Volume III (June 2020)
NIHL Claims: A Collection of Articles from BC Disease News
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NIHL Claims:
A Collection of Articles from BC Disease News
Volume III
CONTENTS
PAGE 6 Introduction
PAGE 7 Hearing Loss and Anaemia (BCDN Edition 200)
PAGE 7 Drill Bit Wear Intensifies Harmful Exposure at Work (BCDN Edition 202)
PAGE 8 Feature: The New NIHL Fixed Scheme - Will It Save You Money? (BCDN Edition 202)
PAGE 15 Hearing Impairment and Dementia (BCDN Edition 204)
PAGE 16 Date of Knowledge in NIHL Claims: Smith v Brentford Nylon Limited, Shegl Realisations Limited & Dunlop Rubber Company Limited (BCDN Edition 207)
PAGE 17 A Third of Over 65’s May Have Age Related Hearing Loss (BCDN Edition 209)
PAGE 18 Report Finds Aircraft Noise Levels in the US are Within Allowable Limits (BCDN Edition 209)
PAGE 19 Hearing Organisations Call for Policy-Makers To Help Raise Awareness Of The Effects Of Hearing Loss (BCDN Edition 212)
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PAGE 20 Survey Investigates Effects of Hearing Loss on Older British Workers (BCDN Edition 212)
PAGE 21 Survey Investigates Effects of Hearing Loss on Older British Workers (BCDN Edition 212)
PAGE 22 Public Transport Noise Levels Enough to Cause Hearing Damage (BCDN Edition 215)
PAGE 27 Feature: De Minimis and The LCB Guidelines – An Update (BCDN Edition 216)
PAGE 30 Hearing Loss on the London Underground (BCDN Edition 217)
PAGE 30 Hearing Loss in American Agriculture, Forestry, Fishing and Hunting Sectors (BCDN Edition 221)
PAGE 33 Section 33 Discretion in NIHL Claims: Carr v Panel Products Limited [2018] EWCA Civ 190 (BCDN Edition 222)
PAGE 37 Link Between Syphilis and Hearing Loss? (BCDN Edition 223)
PAGE 38 Acoustic Shock: Goldscheider v the Royal Opera House Covent Garden Foundation [2018] EWHC 687 (QB) (BCDN Edition 225)
PAGE 39 Smokers at Increased Risk of Hearing Loss at 4 kHz (BCDN Edition 225)
PAGE 40 Feature: Acoustic Shock: An Update (BCDN Edition 226)
PAGE 51 Feature: Future Hearing Assistance Claims: The McShefferty Papers (BCDN Edition 233)
PAGE 56 Great Ormond Street Hearing Loss Prevention Drug Trials (BCDN Edition 235)
PAGE 56 Feature: Hearing Testing Methods Additional to Pure Tone Audiometry (Part 1) (BCDN Edition 235)
PAGE 65 Feature: Hearing Testing Methods Additional to Pure Tone Audiometry (Part 2) (BCDN Edition 236)
PAGE 73 Feature: Reliability of CERA and PTA Testing: Sumner v Turtle Wax Limited (Liverpool County Court, 2018) (BCDN Edition 237)
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PAGE 77 Hearing Loss Onset 25 Years Post-Noise Exposure: Harte v Hawker Siddeley Dynamics Ltd & 2 Ors (Wigan County Court, 2018) (BCDN Edition 240)
PAGE 79 Feature: A Review of De Minimis in NIHL Claims Post-Dryden: Nicholls v Osram Ltd & Anor (Newcastle County Court, 2018) (BCDN Edition 241)
PAGE 85 Feature: Maximum Bulging at 2 kHz: Callaghan v Imperial Chemical Industries Limited & Anor (2018, Middlesbrough County Court) (BCDN Edition 243)
PAGE 91 Feature: Investigations in Disease Claims: Feature 1 – NIHL Claims (BCDN Edition 244)
PAGE 101 Using 6 kHz as an Anchor Point: Percy v Northern Gas Networks & 2 Ors. (Newcastle County Court, 15 June 2018) (BCDN Edition 245)
PAGE 104 Double Compensation and an Application for Strike Out and QOCS Disapplication: Smith v Baird Clothing Menswear Limited & Ors (2018) (BCDN Edition 245)
PAGE 105 12% Increase in Canadian Worker NIHL Cases as Hearing Protection Uptake Increases (BCDN Edition 245)
PAGE 106 How Do Cognitive and Auditory Factors Affect the Perception of Speech in Background Noise? (BCDN Edition 248)
PAGE 108 More De Minimis Success in NIHL Claims: Wiseman v Overhead Doors (GB) Limited (2018) (BCDN Edition 249)
PAGE 111 Royal Opera House Granted Permission to Appeal ‘Acoustic Shock’ Ruling (BCDN Edition 253)
PAGE 112 Slater and Gordon to Dispense with its NIHL Team Before 2020 (BCDN Edition 254)
PAGE 112 Researchers Identify ‘Essential’ Hearing Loss Gene (BCDN Edition 254)
PAGE 114 Feature: Second Audiograms Underscore Reliability: Pandya v Walkers Crisps Ltd & Anor (Leicester County Court, 2018) (BCDN Edition 257)
PAGE 120 Feature: More Success with De Minimis NIHL Defence: Fotherby v Quibell And Sons Limited & 2 Ors (Sheffield County Court, 2018) (BCDN Edition 258)
PAGE 126 County Court Jurisdiction in Sea-Based Disease Claims: Meeks v BP Shipping and Fyffes (Unreported, 2018) (BCDN Edition 259)
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PAGE 130 Feature: Establishing Breach of Duty in NIHL Claims – ‘Peripatetic’ Noise Exposure and Absent Noise Surveys: Mackenzie v Alcoa Manufacturing (GB) Ltd [2019] EWHC 149 (QB (BCDN Edition 261)
PAGE 137 £1.3 Million Military Deafness Claim Listed for High Court Trial in March (BCDN Edition 262)
PAGE 139 Royal Marine Reaches Agreement with MoD Over £1.3 Million Deafness Claim (BCDN Edition 265)
PAGE 140 Feature: Fundamental Dishonesty Under Section 57 of the Criminal Justice and Courts Act 2015: A Matter for Trial or Interlocutory Application? (BCDN Edition 265)
PAGE 142 US Military Invests in Drug to Inhibit NIHL Onset (BCDN Edition 266)
PAGE 144 Court of Appeal Judgment Reserved in Acoustic Shock Appeal (BCDN Edition 268)
PAGE 146 NIHL Claimant May Face Committal Proceedings for ‘Lying’ (BCDN Edition 270)
PAGE 147 £550,000 Quantum Ruling in Military Deafness Case: Inglis v Ministry of Defence [2019] EWHC 1153 (QB) (BCDN Edition 273)
PAGE 151 Insurer Edges Closer Towards Committal Proceedings Against Dishonest NIHL Claimant: Zurich Insurance Plc v Romaine [2019] EWCA Civ 851 (BCDN Edition 275)
PAGE 154 How Accurate Are ‘Speech Communication Method’-Generated Noise Levels? (BCDN Edition 280)
PAGE 156 Upcoming Interlocutory Hearing to Consider Strike Out of NIHL Claims Handled by Heptonstalls Solicitors for Payment of Incorrect Court Fee (BCDN Edition 283)
PAGE 158 A Barrister’s Comment on the Issue of Whether Service of Particulars of Claim Always Requires Concurrent Service of a Medical Report? (BCDN Edition 285)
PAGE 164 NIHL Claims NOT Struck Out, as Heptonstalls Court Fee Saga is Resolved at ‘Show Cause’ Hearing (BCDN Edition 291)
PAGE 167 Study on the Impact of Tinnitus on Professional Musicians to Begin in December 2019 (BCDN Edition 291)
PAGE 170 London Underground Suspend Industrial Action, as TfL Promise to Take Action on ‘Complex’ Tube Noise Issue (BCDN Edition 292)
PAGE 173 Feature: Why is Tinnitus Playing an Ever-Dominant Role in ‘Common Whiplash’ Claims? (BCDN Edition 293)
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PAGE 178 Feature: Allegations of Historic Noise Exposure Devoid of Noise Surveys: Mackenzie v Alcoa Manufacturing (Gb) Ltd [2019] EWCA Civ 2110 (BCDN Edition 299)
Introduction
BC Disease News has covered a wide range of issues that arise in hearing loss claims. This reference guide collates all of our articles into one collection, across four volumes (1 volume for every 100 BC Disease News Editions), with the aim of making the information more accessible and practically beneficial.
Any comments or feedback can be sent to Boris Cetnik or Charlotte Owen.
As always, warmest regards to all.
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Hearing Loss and Anaemia (BCDN Edition 200)
Earlier this year, a study by Pennsylvania State University College of Medicine published in the JAMA Otolaryngology Head & Neck Surgery journal found a positive association between hearing loss and anaemia.
One reason for hypothesising an association is that ‘blood supply to the inner ear via the labyrinthine artery is sensitive to ischemic damage (damage caused by reduced blood flow)’. Another, is that ‘Reduced iron in the body causes the breakdown of lipid saturase and desaturase, both of which are important in energy production and, consequently, the production of myelin’, which coats the auditory nerve and is important for the efficient conduction of signals along its fibres.1
The author of the study, Kathleen M. Schieffer, stated that:
‘… iron deficiency anaemia was positively associated with sensorineural hearing loss and the presence of combined hearing loss’.
‘The overall risk for sensorineural hearing loss in persons with iron deficiency anaemia was 82% higher than for someone without the blood condition and the risk of a mixed hearing loss … was 240% higher than for people without iron deficiency anemia’.2
Although a positive association was found, the author professes that:
‘Further research is needed to better understand the potential links between IDA [iron deficiency anaemia] and hearing loss and whether screening and treatment of IDA in adults could have clinical implications in patients with hearing loss’.3
Drill Bit Wear Intensifies Harmful Exposure at Work (BCDN Edition 202)
Advice from the Center for Construction Research and Training (CWPR) suggests that exposure to noise, silica and vibration, as a consequence of work-related hammer drill usage, can be significantly reduced by replacing components on a more regular basis.4
Using a specially designed test bench, researchers at the University of California were able to investigate the effect of carbide-tipped drill bit wear on drilling efficiency, while drilling through rock.5 It was hypothesised that inefficiency would lead to longer periods of harmful exposure.
The results of the investigation, published in the Annals of Work Exposures and Health, are displayed in the tables below:
1 Tim Newman, ‘Anemia and hearing loss: Is there a link?’ (4 January 2017 Medical News Today)
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VIBRATION:
NOISE EXPOSURE:
It was also discovered that drilling with a dull drill bit increased the amount of breathable silica dust by 80-114%, compared with a sharp drill bit.
The upshot of this investigation has been a recommendation to drill bit manufacturers to introduce ‘wear marks’ on disposable parts. This would indicate that a change of component is necessary.
Feature: The New NIHL Fixed Scheme - Will It Save You Money? (BCDN Edition 202)
Introduction
In edition 199 of BC Disease News (here), we reported that the Civil Justice Council’s NIHL Working Party had published its final report entitled, ‘Fixed Costs in Noise Induced Hearing Loss Claims’ and proposed a fixed fee scheme for handling NIHL claims. In this feature, we consider whether insurers will achieve a lower indemnity spend under a fixed fee scheme compared to current handling regimes.
The fixed fee scheme - a recap
But first, let’s remind ourselves of the proposed fixed fee regime which would apply to more ‘straightforward’ NIHL claims. The Working Party report states that these claims ‘are still the majority’. As such, the proposed matrix of costs is restricted to cases which would remain within the fast track (both on value and on complexity), cases which are considered less suitable for fixed costs, or are more complex than the norm, for example: 1. Single defendant cases where the defendant puts their name on a list for all their cases to commence within the EL/PL portal 2. Single defendant cases commenced within EL/PL portal which subsequently fall out of the portal. 3. Military claims. 4. Claims valued at more than £25,000. 5. Claims with more than 3 defendants. 6. When a defendant argues in their letter of response: a. The occupational loss is de minimis b. Requests a second audiogram c. Requests their own medical evidence d. Treats this as a ‘test case’ (the scope of this has not been agreed).
Any argument by any defendant under 6 a) to d) will remove the ‘whole case’ from the fixed fee regime. So once the claim falls out of scope for fixed fees it cannot come back in and costs going forward will be assessed on the standard basis. This is not the same where claims, pre-litigation, are run under the fixed fee regime and then fall out once litigation has started. These claims will attract the fixed fee outlined for pre-litigation but the post litigation costs will be paid on the standard basis.
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The scheme includes: - A new letter of claim which will need to be accompanied by: o An audiogram produced by a suitably experienced and approved provider; o Schedule of employment from HMRC; and o Search results from the Employer’s Liability Tracing Office (ELTO). - Audiograms will need to be from an ‘acceptable UK “quality standard” audiologist’ and the test must be conducted in acceptable conditions. - A new letter of response.
The scheme is underpinned by single audiometry. For reasons we have extensively reported on in editions 2 (here) and 160 (here) of BC Disease News, this will inevitably result in claimants without NIHL being paid compensation, even where the audiometry is performed under acceptable conditions. Based on our most recent analysis of over 20,000 claimant audiograms c. 95% are diagnostic of NIHL when there is a simplistic application of the CLB6 / LCB7Guidelines.
The costs under the scheme
Pre-litigation
There are 4 different procedural stages defined in the Working Party’s report, as follows:
Liability Is Admitted
2A = A claim that settles before the claimant’s solicitor has prepared papers to issue proceedings. 2B = A claims that settles after the claimant’s solicitor has prepared papers to issue proceedings.
Liability Is Denied
3A = A claim that settles before the claimant’s solicitor has prepared papers to issue proceedings. 3B = A claim that settles after the claimant’s solicitor has prepared papers to issue proceedings. The fixed costs are determined by the stage at which a claim concludes and also the number of defendants involved-with an additional £500 for each defendant successfully pursued as shown in the table below:
All these fees are exclusive of VAT and any reasonable disbursements.
In addition, restoration fees of £1,280 (exclusive of VAT) per restored defendant successfully pursued will be paid, plus any reasonably incurred disbursements but not counsel’s fees.
Litigation
Pre-litigation costs will be paid as per fixed costs - irrespective if the claim falls out of the regime on litigation, with post litigation costs paid on a standard basis. Below is the proposed matrix of fixed recoverable costs for litigated NIHL claims:
6 Coles R.R.A., Lutman M.E., Buffin J.T. (2000) Guidelines on the diagnosis of noise-induced hearing loss for medicolegal purposes. Clin. Otolaryngol. 25, 264-273. 7 Lutman M.E., R.R.A Coles, Buffin J.T. (2015) Guidelines for quantification of noise-induced hearing loss in a medicolegal context, on-line.
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The £4000 figure for pre-issue in this matrix refers to the pre-litigation fee in the table above for the category ‘3B’ i.e. a single defendant where the claimant solicitor has prepared papers to issue proceedings (which of course they would have if this litigated matrix is being used). As per the pre-litigation matrix, £500 is added per extra defendant.
Once the claim is issued, post litigation costs for a single defendant (excluding VAT and reasonable disbursements) are as follows:
For each additional defendant successfully pursued a 20% uplift is applied per defendant at each stage.
The figures in the post-litigation matrix are cumulative so you can see that once the claim is issued, but not yet allocated, a single defendant claim would have a fixed fee of £5,650. We have broken down each stage, along with the uplift calculations for extra defendants below:
Post Issue – Pre Allocation Calculation
£4000 (pre-litigation fee) + £1,650 (issued to allocation for single defendant) = £5,650. If there is an extra defendant, you must add £500 from the pre-litigation stage to 20% of the £1,650 (£330) issue to allocation fee, which will give you the £830 uplift at this stage.
Post Allocation – Pre-Listing Calculation
If the claim is then allocated but not yet listed, another £1,656 can be added, which represents the £7,306 figure.
Again, if there is an extra defendant, you must add the £500 from the pre-litigation stage to the 20% uplift for the issued to allocation stage (£330) and 20% of the post allocation to listing fee (£331) which will give you the £1,161 uplift for this stage.
Post- Listing – Pre Trial Calculation
Finally, once the claim is listed £1,881 can be added which equates to £9,187 as above.
If there is an extra defendant, you must add the £500 from the pre-litigation stage to the 20% uplift for the issued to allocation stage (£330), plus 20% of the post allocation to listing fee (£331) and 20% of the listing to trial fee (£376) which will give you the £1,537 uplift.
In addition to the above and as previously stated, a fee of £1,280 would be recoverable for restoring a company to the register.
The Working Party did not reach full agreement on the trial advocacy fee, however, Jackson recommended that these be the same as those proposed for Band 4 claims in the new ‘intermediate’ track i.e. £1,380 so this can be added to the final fee of £9,187.
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Each stage in the post-litigation fixed fee matrix also has the 20% figure which would need to be added for each extra defendant.
Where there is more than one defendant, the applicable fees for pre and post-litigation can become fairly complicated and difficult to navigate. As such we have created an easy to use tool which will calculate the fees available depending on each particular scenario - please contact us if you would like a copy.
Current spend
Spend on NIHL claims is largely driven by repudiation rates and leakage into litigation. The more claims that can be successfully repudiated pre-litigation the lower the spend. In edition 144 of BC Disease News (here), we reported on the Institute and Faculty of Actuaries UK Deafness Working Party statistics indicating that the mature repudiation rate for claims notified between 2013-2015 notification years would be c.75%. This was significantly higher than the mature repudiation rate for 2010-2012 claims (between 52% and 64%). We also reported (here) that Aviva’s repudiation rate was 85% in 2015.
Let’s look at the estimated spend of settling 1,000 NIHL claims applying differing repudiation rates and assuming 5% of claims leak into litigation.
For all scenarios, we assume typical spend as shown in the table below. It is assumed that currently most claims involve relatively low level NIHL with average damages of £5,000.8
Assumed typical spend per NIHL claim
Scenario 1 - 90% Repudiation Rate
Overall 900 claims are repudiated and 100 are paid. 50 claims leak into litigation. 950 claims are concluded pre- litigation - 865 defended and 85 paid. In all scenarios, we assume 70% of claims which leak into litigation are repudiated - i.e. 15 paid in litigation and 35 defended in litigation.
Therefore, of the 900 claims repudiated, 865 are pre-litigation and 35 are litigated.
Of the claims paid, 85 are pre-litigation and 15 are litigated-see figure of claim outcomes below.
8 Our analysis of c. 10,000 audiograms on first introduction of the LCB Guidelines indicated 75% of claims with NIHL of 10 dB or less applying the LCB full method to determine disability.
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Applying the above assumed spend per claim, then the overall spend is £2,590,000 as shown in the figure below.
With each 10% increase in the repudiation rate the overall spend decreases by an average of £1,165,200 - see the figure below.
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Spend under the new fixed scheme
The dynamic of claims handling may well change under the fixed fee scheme and over time some insurers may adopt a no fault liability approach, similar to that under the historic ‘GMB-Iron Trades Scheme’. In our first scenario below we assume 80% of claims paid and 20% repudiated. We again assume: - -average damages of £5,000 per claim - -average disbursements of £1,000 per claim - -5% leakage into litigation - -A broadly equal spread of claims settling at the different procedural stages of the fixed fee scheme
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So, with 80% of claims paid, the total indemnity spend is just under £7.9 million.
This is the equivalent spend which would be reached with a c. 45% repudiation rate under current handling.
Any current repudiation rates above 45% means that indemnity spend would increase under the new scheme.
In the table below we show how spends would differ by repudiation rates.
Table: Spend comparison between current & fixed fee scheme (assuming 80% claims paid under scheme)
Making your own assessment on spend
We have prepared an easy to use calculator to compare your current claims spend against predicted spend under the new fixed fee scheme. You will need to know: - Your pre-litigation repudiation rate - Current pre-litigation claim cost for a repudiated claim - Current pre-litigation claim cost for a paid claim - Your % leakage into litigation - Your litigation repudiation rate - Current litigation claim cost for a repudiated claim - Current litigation claim cost for a paid claim
You can assume different repudiation rates under the fixed fee scheme and assess spend outcomes. For access to the calculator please contact [email protected]
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We will shortly publish a full White Paper on the scheme which outlines its potential risks on damages, claims volumes and costs.
Hearing Impairment and Dementia (BCDN Edition 204)
In edition 129 of BC Disease News (here), we discussed suggestions that dementia prevalence has risen, because of a system of hearing aid rationing, introduced by the National Health Service (NHS). Out of 11 million people in the UK estimated to have impaired hearing, just 1.4 million use hearing aids.9 Using hearing aids has been shown, by an extensive French study, not just to maintain the same cognitive levels as those without hearing loss, but also to treat cognitive decline in those with hearing loss. Criticism has therefore been directed at NHS rationing, after physician, Frank Lin, theorised that up to 36% of dementia sufferers, with impinged memory function, may have overtaxed their brains when straining to hear. This week, we report on recently published research from three separate studies, each of which tested the association between dementia and hearing loss.
Currently, there is no scientifically proven causal relationship between hearing loss and cognitive decline, although a comprehensive report from the Lancet Commission on Dementia Prevention, Intervention and Care referred to hearing loss as one of nine risk factors increasing the risk of dementia.10 It has been assumed by researchers that reduced audiological input and social isolation, caused by a loss of hearing, may explain a potential relationship.11
This year, an English study established that the risk of dementia in over 50s was 40% greater in those who reported having moderate hearing loss and 60% greater in those who reported having poor hearing.12 The author of the study stated:
‘these findings are consistent with the rationale that correction of hearing loss could help delay the onset of dementia or that hearing loss itself could serve as a risk indicator for cognitive decline’.
Meanwhile, researchers in Germany analysed 4 years’ worth of insurance records, containing over 14,000 incidents of dementia and concluded that hearing loss sufferers had a 20% to 40% higher risk of developing dementia than those who were not hard of hearing.13 This increase in risk was not consistent with cases of unilateral hearing loss, however.
Finally, results of a Taiwanese study, comparing approximately 4,000 people without age associated hearing loss (AAHL) with an equal number of AAHL sufferers, found that those diagnosed with AAHL were 30% more likely to have dementia.14
Further findings from the Taiwanese study demonstrate that co-morbidities, such as rheumatoid arthritis, hypertension, diabetes and stroke, put people at 3.6 times the risk of dementia, which is, admittedly, far greater than the risk that hearing loss poses.
9 ‘Statistics’ (Action on Hearing Loss)
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Date of Knowledge in NIHL Claims: Smith v Brentford Nylon Limited, Shegl Realisations Limited & Dunlop Rubber Company Limited (BCDN Edition 207)
In the first edition of BC Disease News, we discussed how defendants in noise induced hearing loss claims would be impacted by the Court of Appeal decision in Johnson v Ministry of Defence [2013] P.I.Q.R. P7, which ruled on limitation. In September of this year, a County Court judgment was handed down in the case of Smith v Brentford Nylon Limited, Shegl Realisations Limited & Dunlop Rubber Company Limited, which has ruled on the same issue.15
Under s.11 of the Limitation Act 1980, a NIHL claimant’s cause of action starts on the date NIHL is caused or the date of knowledge of the person injured.
The definition of ‘date of knowledge’ is located in s.14(1):
Knowledge is subject to an objective test, detailed in s.14(3):
In most hearing loss cases, applying a test of reasonable objectivity, it is difficult for claimants to argue that they recognised significant hearing loss as being potentially attributable to their employment at a later date than when hearing loss could have been diagnosed, either by themselves, or with the help of an expert. Claims, in which the date of first onset and the date of knowledge are years (possibly decades) apart, are most common in occupations where hearing protection and information surrounding noise-related risks were not readily available.
As a reminder, in Johnson, s.14(3)(b) was analysed in greater detail by the judge, Dame Janet Smith, questioning what curiosity a 21st century man would have in respect of his perceived deafness, to trigger the consultation of expert medical advice. At paragraph 28 to 29, the judge opined:
‘In the circumstances I think that a reasonable man would have consulted his GP about his deafness ... It follows that I think it probable that if the GP had been consulted as to the cause of the deafness, he would have asked about the appellant’s employment history and the possibility of noise deafness would have come to light’.
However, the judge tempered the harshness of her ruling, at paragraph 31, by allowing:
15 ‘Johnson v MoD and date of knowledge in noise-induced hearing loss limitation trials’ (13 October 2017 Zenith PI)
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‘... some ‘thinking time’ between the time when he realised that he had a significant condition and the date on which he ought reasonably to have taken expert advice. The time to be allowed must depend on the nature of the condition but, with a condition such as deafness which presents in an insidious way, I would be prepared to allow about a year for consideration’.
Therefore, an extension of around 12 months may be granted, from the moment of initial realisation of hearing loss, in order to attribute the symptoms of deafness with the relevant period of noise exposure.
In Smith, the claimant alleged that he became aware of his hearing loss shortly before having received a leaflet, in August of 2014, which invited hearing loss sufferers, who had been employed in noisy industrial environments, to call a telephone enquiry number. The realisation of the link between his former occupation and his recently perceived deafness was alleged to have occurred shortly after the leaflet was delivered and this date was reflected on the claim form.
Johnson was applicable to Smith on the facts, given that both claimants were relatively young (Mr Johnson was 61 and Mr Smith was 68) and both periods of noise exposure had occurred many years in the past (for Mr Smith, 30 years ago). Under the objective test, extended by a year of thinking time, in Johnson, Mr Smith’s date of knowledge had to be, at most, one year after the date when significant hearing loss was first acknowledged which he said was shortly before receiving the leaflet. If it were not, the claim would be statute barred. As mentioned above, the claimant alleged his date of knowledge was shortly after the leaflet was delivered, so no longer than the year.
However, HHJ Gargan, handing down judgment in September of 2017, reached the conclusion that the claimant had likely been aware of his suffering with significant hearing loss before the date of knowledge asserted by the claim form, indeed, she concluded he would have been aware for a period in excess of a year preceding receipt of the leaflet. The claimant would not have understood the relevance of the leaflet, otherwise. Thus, the claim was statute-barred.
In order to distinguish the case of Johnson on the facts, the hearing loss must be slight, and/or the claimant must be significantly older than Mr Johnson was at the date of first knowledge. If the claimant is successful in doing so, the date of knowledge, between having first noticed significant symptoms of deafness and the date at which these symptoms are objectively attributable to noisy employment, may stretch beyond the shorter period of one year, prescribed by Johnson.
A Third of Over 65’s May Have Age Related Hearing Loss (BCDN
Edition 209)
A Dutch study has looked into the prevalence of age-related hearing loss (AHL), in order to better understand the extent to which hearing loss increases with age.16 For elderly patients, bringing noise induced hearing loss claims, AHL, or Presbycusis, is often used as a causation defence to causation arguments made by claimant solicitors, when analysing audiograms. Indeed, we wrote, in a previous edition (here), that by the age of 80, it is arguable that noise exposure has virtually no impact on an individual’s hearing ability.
4,743 test subjects, aged 50 and over, were selected from the National Health Interview Survey (NHIS) and included in the study. Results, published in the Laryngoscope and Disability and Health Journal,17 showed that, for persons over the age of 65, hearing loss of greater than 35 dB was 33% and 29% between 0.5 kHz and 4 kHz, among men and women, respectively. Further, hearing loss of 41 dB or higher was recorded in 21% of men and 18% of women.
The authors of the study observed a decreasing discrepancy in figures between men and women, when compared with the results of older cohort studies, especially at the higher frequencies of 4 kHz and 8 kHz. The reasoning given for this finding was that gender equality is playing a lesser role in bringing about the environmental factors which might result in the onset of hearing loss.
16 ‘One in three aged 65 or older has an age-related hearing loss’ (14 November 2017 Hear It)
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Report Finds Aircraft Noise Levels in the US are Within Allowable
Limits (BCDN Edition 209)
The United States Government Accountability Office (GAO) has published a report on noise levels experienced by crewmembers on commercial service aircraft and their access to hearing protection.18 GAO examined, firstly, knowledge surrounding aircraft cabin and cockpit noise levels and how this compares with occupational noise exposure standards. Secondly, it examined a selection of airline policies on hearing protection for crew members.
GAO reviewed regulations and guidance, relating to occupational noise, from the Federal Aviation Administration (FAA), the Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH). Accordingly, OSHA and NIOSH databases were scanned, in order to find reports of enforcement activity, in relation to aircraft noise, as well as reports on noise interference with onboard communication. In addition, academic, Government and trade publications were searched for studies measuring noise levels inside aircraft. 10 suitable studies were identified. Interviews with officials from FAA, OSHA, NIOSH, labour groups, aviation trade associations, aircraft manufacturers and eight airlines were conducted.
The review of studies and data were suggestive of the fact that aircraft cabin and cockpit noise levels do not exceed the OSHA standard. Further, none of the studies detected noise levels which clearly exceeded the OSHA standard, although two of the studies found that noise exposure over long durations, in certain types of aircraft, may reach the more restrictive NIOSH exposure limit. As such, few noise level related complaints have been received by OSHA and the FAA.
Moreover, officials from four aircraft manufacturers confirmed that cabin and cockpit noise levels are tested in each new model of aircraft, and have measured sub-OSHA levels. However, officials from the labour groups which represent pilots and flight attendants told GAO that, while noise levels are unlikely to exceed the OSHA standard, they believe crewmembers may be exposed to unsafe levels of noise on occasion.
Eight different airlines reported varying policies regarding availability and use of hearing protection. All of them reported that pilots are allowed to wear hearing protection, such as earplugs, or noise-reducing headsets, while five airlines reported that flight attendants are allowed to wear earplugs during flight operation. However, labour group officials admitted that the number of crewmembers using hearing protection may be limited. For pilots, comfort, expense, and incompatibility with aircraft communication systems may explain the reasoning behind limited usage of hearing protection.
In summary, the report found that noise levels do not generally exceed allowable limits, and that hearing protection is generally available, in spite of its varying use.
18 Commercial Aviation: Pilots’ and Flight Attendants’ Exposure to Noise aboard Aircraft. GAO-18-109R. Government Accountability Office. 15 November 2017
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Hearing Organisations Call for Policy-Makers To Help Raise
Awareness Of The Effects Of Hearing Loss (BCDN Edition 212)
Eight organisations have formed The European Coalition on Hearing Loss and Disability and are calling on European policy-makers to help to raise awareness of hearing loss.19 The members of the coalition are: • Health First Europe • The European Federation of Hard of Hearing People • The European Association of Hearing Aid Professionals • AGE Platform Europe • European Association of Cochlear Implant Users • The European Hearing Instrument Manufacturers Association • The Ear Foundation (UK) • The International Federation of ORL Societies.
According to the coalition, 10 % of the total population of Europe (52 million people) self-report experiencing hearing loss. Of these, 73 % consult a medical professional, but only 50 % are referred to hearing care professionals. Other sources have reported that up to 16 % of adult Europeans suffer from hearing loss that is great enough to have adverse effects on their everyday life20.
In their manifesto21, the Coalition reports that,
‘Hearing loss is a huge problem for the health of Europe’s citizens, threatening to put huge pressure on Europe’s health and social care systems if left untreated. Innovative medical technology, such as hearing aids and hearing implants, can alleviate the burden. Action from European policy-makers is called to help raise awareness of this condition, look at effective ways of prevention, facilitate access to these technologies where appropriate, improve care and share best practices among Member States’.
The Coalition calls upon the Member States: 1. To share best practice on hearing care 2. To integrate strategies for hearing care into primary health care systems 3. To promote access to hearing devices 4. To remove age limits in disability support measures that prevent older persons with disabilities, such as hearing impairment, from enjoying their rights under the United Nations Convention on the Rights of Persons with Disabilities (CRPD) 5. To promote effective initiatives to improve access to information 6. To ensure education and recognition for hearing care professionals in their country.
The Coalition calls upon the European Commission and the Council: 1. To take the lead in ensuring the access to professional hearing care is a right 2. To support member states to co-ordinate health policies 3. To develop a European strategy on hearing loss 4. To launch programmes to increase awareness of the effects of hearing loss on everyday life and overall health 5. To invest in research on hearing loss.
The manifesto outlines some of the effects of hearing loss, at both personal and societal levels. It also provides references to studies in which interventions have reduced some of these effects.
The World Health Organisation estimates that in Europe the total cost of untreated hearing impairment amounts to € 178 billion each year. These costs are due to health system expenditure, loss of productivity caused by unemployment and premature retirement, societal costs, and costs of educational support for children with hearing
19 Action from European policy-makers is called for to help raise awareness of hearing loss. Hear-it.org 1 December 2017 https://www.hear-it.org/action-european-policy-makers-called-help-raise-awareness-hearing-loss (Accessed 12 December 2017) 20 One in Six Adults Suffers from Hearing Loss. Hear-it.org https://www.hear-it.org/one-in-six-adults-suffers-from-hearing-loss-1 (Accessed 13 December 2017) 21 Manifesto on Hearing Loss and Disability The European Coalition on Hearing Loss and Disability. http://www.ehima.com/wp- content/uploads/2017/11/Manifesto-Hearing-Loss-and-Disability-1711-Final.pdf (Accessed 13th December 2017)
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loss. Early retirement and unemployment may require an individual to need state benefits. At the patient level, hearing loss can reduce a person’s chances of employment, lead to greater amounts of sick leave and limit opportunities for career progression. Several studies are referred to in which prevention or treatment of hearing loss has reduced a patient’s chance of unemployment.
In children, hearing loss can reduce their ability to learn. However, studies have shown that use of hearing devices, such as cochlear implants, allow greater numbers of hearing impaired children to attend mainstream fulltime education and to reach age-appropriate educational standards.
Hearing loss can also have effects on general health. Hearing loss is associated with cognitive decline such as dementia, depression, becoming dependant on others, and increased risk of accidents. The burden of hearing loss is going to increase as the population ages and the numbers of older people increase. In older people, hearing loss can increase dependence on others, which may accelerate progression into care homes or similar. Lack of independence in older people can also lead to depression and loss of productivity.
Prevention and treatment of hearing loss could attenuate some of the adverse effects mentioned above, and this is among the objectives of the Coalition. National screening programmes and easier access to interventions such as cochlear implants and hearing aids can help to address hearing loss. The WHO recognises the need for screening programmes for groups of people including those exposed to noise in occupational and recreational settings.
In summary, the coalition aims to raise awareness of the adverse effects of hearing loss, including societal costs and personal welfare, and to mitigate these effects by provision of better access to prevention and treatment programmes.
Survey Investigates Effects of Hearing Loss on Older British Workers (BCDN Edition 212)
According to a survey by the English marketing company OnePoll, 60 % of workers of the age of 55 or over have noticed that their hearing is deteriorating and that it affects their ability to perform at work. The survey, of 800 workers, looked at the effects of hearing loss in the workplace22.
A reduction in confidence due to hearing problems was reported by 40 %, and feeling less productive and marginalized were other significant sources of anxiety. The first signs of hearing deterioration were having to ask colleagues to repeat themselves, reported by more than half the respondents, and having to concentrate much harder to follow conversations and increasing the volume on laptops and phones.
The survey found that communication at work becomes more difficult in many with hearing deterioration. Almost half of respondents say they would avoid using the telephone at work, and a third say they try to avoid meetings. A quarter said that they avoid socializing with colleagues, to keep their hearing loss hidden.
General background noise and colleagues not talking clearly were the two most challenging listening scenarios, reported by more than half of the respondents.
Almost half of the respondents reported having to ask colleagues to speak more loudly or to repeat themselves. Around 30 % said they carefully choose locations for meetings, and around 20 % use lip reading.
Many reported that they do not tell their colleagues or employer about their hearing loss. More than half the respondents were concerned that their employer would not be supportive, and thus they keep their hearing loss to themselves.
22 Hearing loss fear in the workplace for British ageing workers. Smallbusiness.co.uk. 28 June 2017 http://smallbusiness.co.uk/hearing-loss-fear-workplace-2539330/ (Accessed 13 December 2017)
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The main reasons why workers were not addressing their hearing loss, by for example, taking a hearing test and investing in hearing aids, were that they wanted to feel younger and more proficient. Four in ten respondents said they would not wear a hearing aid because it would make them look and feel old, and two in ten had concerns that colleagues would perceive them negatively.
Public Transport Noise Levels Enough to Cause Hearing Damage (BCDN Edition 215)
The levels of noise to which commuters in Toronto are exposed were measured in a new study23. Though the mean noise levels were within the recommended level of safe noise exposure, cumulative bursts of loud noise have the potential to place individuals at risk of hearing damage due to noise.
The researchers took measurements of noise levels using a dosimeter attached to a shirt collar, 2 inches away from the ear. A number of transportation methods were investigated, including buses, streetcars, private car, cycling and walking.
The average noise levels ranged from 67.6 dB in a personal car to 81.8 dB on a bike. The mean maximum levels recorded for each transport type ranged from 108.6 dB in a streetcar to 123.8 dB on a bike. Peak noise exposures did not differ significantly between combined subway, streetcar or buses, however, the mean peak noise levels were louder in subway vehicles than subway platforms. In contrast, for buses, mean peak noise was louder on bus platforms than within buses. Bus platforms were also found to be on average louder than subway and streetcar platforms. Within personal transport options, cyclists were exposed to louder peak noise than pedestrians. For public transport users, the loudest sound measurement came from a bus stop (128.1 dB) and the loudest peak sound for personal transport was while biking (135 dB).
The Environmental Protection Agency (EPA) states that exposure to 114 dB for more than four seconds can damage hearing24. The mean peak exposures on bus platforms and while cycling were greater than 114 dB, and individual measures greater than this level were found: within subway vehicles, streetcars and buses; within personal cars; whilst biking and walking; and on subway and bus platforms. Up to 20 % of subway measurements had mean peak noises greater than 114 dBA, and up to 85 % of bus platform measurements exceeded this threshold, with 54 % greater than 120 dBA. The frequency with which peak noise levels exceed 114 dB is perhaps the most important finding from this study.
The researchers also considered the average length of time spent commuting, which correlated with an EPA recommended noise exposure of approximately 85 dB as average. This level of average noise exposure was exceeded in 9 % of subway measurements, 12 % of bus measurements, and 14 % of biking measurements. None of the streetcar, personal car or walking measurements exceeded this threshold.
The researchers concluded that, given sufficient exposure duration, noise levels associated with mass transit are sufficiently intense to produce noise induced hearing loss in commuters. Noise exposures from personal transportation methods such as cycling are also intense enough. This study demonstrates a significant non- occupational source of noise exposure that is likely to affect many people.
23 Yao, C. M. K. L., Ma, A. K., Cushing, S. L. & Lin, V. Y. W. Noise exposure while commuting in Toronto - a study of personal and public transportation in Toronto. Journal of Otolaryngology - Head & Neck Surgery 46, 62 (2017). https://journalotohns.biomedcentral.com/articles/10.1186/s40463-017-0239-6 (Accessed 11 January 2018) 24 Take public transit to work? Your hearing may be at risk, researchers say. Safety and Health Magazine, 26 December 2017 http://www.safetyandhealthmagazine.com/articles/16547-take-public-transit-to-work-your-hearing-may-be-at-risk-researchers- say (Accessed 11 January 2018)
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Feature: De Minimis and The LCB Guidelines – An Update (BCDN Edition 216)
Introduction
We discussed the issue of de minimis in NIHL claims in editions 3, 93, 108, 133 and 161 of BC Disease News i.e. does NIHL of a magnitude of only a few decibels, or, outside of the key frequency range for hearing, materially affect the claimant?
This week, we revisit the topic in light of the recent decision in Evans v Secretary of State for the Department of Energy & Climate Change and JJ Maintenance Limited (12th December 2017, Cardiff County Court), in which the LCB Guidelines (2016) for the quantification of NIHL were utilised, alongside a de minimis defence.
Background to De Minimis
For the purposes of this article, it is worth revisiting the topic of human hearing. The human range of hearing is between in the region of 20 Hz and 20 kHz in children and young adults but with the high range frequencies at 8 kHz and above fading with age.
The human voice produces sound within a frequency range of about 60 Hz-7 kHz but most human speech falls within a range of 250 Hz-3 kHz. The primary importance of sound within the human speech frequency range of 250 Hz-3 kHz is internationally recognised in the transmission of speech through telecommunications networks with circuitry designed to capture sound within that range only.
However, sound at 4 kHz can also play a part in speech recognition. According to an Irish Expert Hearing Group ‘each individual frequency supplies a different quantity of information for understanding speech. All frequencies between 250 Hz and 4,000 Hz contribute to speech comprehension, but some are more important than others. The most important frequency for understanding speech in a quiet environment is 2,000 Hz. The other frequencies, e.g. 250 Hz, 500 Hz and 4,000 Hz, are less important’.25 Importantly the same Expert Hearing Group concluded that ‘frequencies of 6,000 Hz and 8,000 Hz carry no information for speech comprehension’. This is reflected within the figure below reproduced from the Group’s report showing the frequency ranges important for understanding speech.
25 Hearing Disability Assessment, Report of the Expert Hearing Group, Department of Health and Children (Ireland) 1998.
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De Minimis NIHL?
With the nature of human hearing in place, we can now ask how the legal principles are to be applied in NIHL cases. Is hearing loss of only a few decibels actionable? Similarly, is more significant hearing loss outside of the key frequencies for human hearing – that is 250 Hz-3 kHz – actionable? We posed these questions in earlier editions of BCDN – where did we leave this topic?
Case Law Thus Far
To our knowledge there have now been 8 County Court decisions which address de minimis arguments in NIHL claims (there are no doubt other decisions out there). Defendants have succeeded in 3 of these cases which we summarise below:
Evans v Secretary of State for the Department of Energy and Climate Change
Let us turn to the facts of the case in Evans.
The claimant claimed damages from 2 of his former employers for NIHL, including for the provision in future years of hearing aids and for the maintenance of those aids.
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He was employed by the 1st defendant, NCB, from 1975-1979 and by the 2nd defendant as a general labourer from 2000-2010. It was estimated by an acoustic engineer that the claimant’s Noise Immission Level (NIL) was in the region of 104 dB and this was accepted by both parties. This took into account any hearing protection worn by him. Both defendants conceded breach of duty and neither advanced a limitation defence.
The parties also agreed, applying the criteria in Coles 2000 Guidelines, that the claimant had suffered NIHL as a result of his exposure to noise in his various employments. The agreed NIL satisfied R2 requirement of the Guidelines, the audiogram showed a high-frequency hearing loss in both ears consistent with the R1 requirement of the Guidelines and the experts agreed that there was a bulge at 3 and 4 kHz in both ears consistent with the R3 requirement.
However, the defendants disagreed about the quantification of that hearing loss and about whether the loss was significant or appreciable and so submitted that unless the claimant could prove, on the balance of probabilities, that his hearing loss was significant or appreciable that it should be treated as ‘de minimis’ or non-compensable.
The expert for the claimant was Mr Singh and the expert for the defendant was Professor Lutman. The claimant was examined by Mr Singh in February 2013 and complained that he had hearing difficulties for around 1 to 2 years. His right ear was subjectively his worst hearing ear and he found his hearing loss to be problematic in domestic and social situations e.g. having to turn up the volume on the television and struggling to hear conversation. He did not report suffering from tinnitus.
Two audiograms were carried out by Mr Singh on the claimant with the results as follows:
Mr Singh, relying on figures in the ‘Black Book1’, assessed the claimant’s average hearing loss over 3 and 4 kHz as 11.2 dB. Professor Lutman, however, relied upon the recent LCB Guidelines (2016), to quantify the claimant’s loss over 1, 2 and 3 kHz, which he assessed to be 1.1dB which he argued was too small to have a noticeable effect on the claimant’s day-to-day hearing ability.
The LCB Guidelines (2016) assume that the ‘anchor point’ threshold values, typically at 1 and 8 kHz, will to some extent be affected by NIHL. To assume that the thresholds at the anchor points are purely down to AAHL will under- estimate the NIHL component. The new guidelines offer a method for estimating the NIHL at the anchor points and obtaining AAHL data against which to better compare the claimant’s hearing thresholds and most accurately quantify the NIHL.
Mr Singh did not agree with Professor Lutman’s use of the LCB guidelines which he referred to as ‘illogical and unfair’. In support of this he relied upon a joint statement in a previous case from 2014 in which Professor Lutman appeared
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to accept Mr Singh’s suggestion that the logical problems with the LCB guidelines could be avoided by assessing the binaural loss at 2, 3 and 4 kHz.
Professor Lutman in the present case conceded that if LCB 2016 was strictly used with 1 kHz as the lower anchor point, the estimation of NIHL, might be distorted.
In relation to this HHJ Bidder QC, stated at para 18 of the judgment:
‘It seems to me that that must be taken as a concession by one of the authors of the 2016 paper that that paper needs refinement. While it is, I accept, a peer-reviewed paper in a respected journal, it should be noted that the authors specifically describe it within the paper as a “proposal”. While Miss Williams for the Defendants tells me, and I accept from her, that LCB 2016 has been accepted by some 1st instance judges (and, no doubt, rejected by others) it has not been considered at an appeal level’.
He also went on to point out that the parties had not cited any responses by experts in this field to the proposals in the 2016 Guidelines. As such, in relation to the Guidelines HHJ Bidder concluded:
‘Given that Prof Lutman accepts, in this case, that strict adherence to the paper by use of the 1 kHz level as an anchor point may distort the estimation of NIHL in this case, I do not consider that it is necessary for me to conclude, on a balance of probabilities, that that paper must be accepted as some sort of “gold standard” for the quantification of NIHL’.
Professor Lutman, accepting the distortion caused by taking 1 kHz as the lower anchor point, made an adjustment recommended in the 2016 Guidelines where there is a steep fall off at 8 kHz and he replaced the measured thresholds at 1 kHz with a value of 7 dB (instead of the measured value of 15dB). 7 dB corresponds with the 50th percentile for age associated hearing loss at 1 kHz. Once that procedure was adopted, the NIHL was then assessed as 2.3 dB (binaural 1, 2, 3 kHz average). Professor Lutman, again contended that this loss was too small to be noticeable and in cross-examination, Mr Singh agreed with this.
However, Mr Singh, argued that hearing at 3 and 4 kHz are also very important in terms of speech intelligibility. He submitted that in the Black Book, there is an acknowledgment that the adoption of the 1,2 and 3 kHz frequencies for conventional noise loss should not imply the absence of any disability in some individuals with hearing losses restricted to frequencies outside that rage – with there being a significant loss at 3 and 4kHz in this case.
He also relied on a paper written by Professor Moore of the Cambridge Neurosciences Department in July 2016, published in the International Journal of Audiology. This paper summarises a large amount of research material which, Mr Singh contended, supported the importance of hearing loss at 4 kHz. In particular it states at page 131:
‘There are many studies showing that frequency components above 3 kHz contribute to speech intelligibility for people with normal hearing’.
The paper goes on to use the example of a man aged 55 assessed using the LCB 2016 guidelines to which he said:
‘The mean estimate of the NIHL at 1, 2 and 3 kHz is only 2.4 dB which would usually be considered as of not importance. The mean estimate of the NIHL at 1, 2 and 4 kHz is more substantial, at 11.7 dB…This example illustrates how the noise-induced component of the hearing loss at frequencies above 3 kHz can lead to some increase in difficult in understanding soft speech in quiet and a marked increase in difficult in understanding speech in background noise’.
Professor Moore, also presents research which alleges that hearing the voices of women and children and certain bird song may be compromised by hearing loss at 4 kHz and above and that the ability to determine whether a sound is coming from in front or behind.
Finally, the following statement of Professor Moore was also relied upon:
‘Therefore the audiometric threshold at 4 kHz and possibly also at 6 kHz, should be taken into account when considering compensation for occupational NIHL in a medico-legal context. A major complaint of people with NIHL
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is difficulty in understanding speech in noise. A good predictor of the ability to understand speech in noise for people with NIHL is the average audiometric threshold at 2 and 4 kHz’.
Professor Lutman rejected this analysis and contended that the loss of 11dB at 3 and 4 kHz could not be taken to be significant because of the lack of published research as to whether such losses at those frequencies have any impact. He relied upon his previous collaborative work undertaken with Professor Moore in which they were unable to find a statistically significant effect of that additional hearing loss and moreover, that any trend showed minimal effect. Indeed the specific finding (as written by Moore) was that:
‘Similar to what was seen in the multiple regression analysis above, there is a trend (not statistically significant) for the additional “bulge” in the audiograms shown above to confer a small decrement in performance on the speech recognition in noise test. From a scientific point of view, the trend should not be relied upon, as it is not statistically significant; in other words there is a chance that a repeat study might not show the same thing’.
HHJ Bidder QC addressed this argument as follows at para 45:
‘Clearly I must give weight to that scientific view of the significance of the evidence. That experiment did not show to scientific probability, the appreciable impact of the higher frequency losses. However, that analysis was in 2014. The larger scale survey which was clearly needed to establish statistical significance, if it could do so, has not taken place and what followed was the Moore survey in 2016 which, in my judgment, on balance of probabilities does establish the real significance of 4 kHz and above to those suffering from an established NIHL at that frequency’.
Professor Lutman also relied on 2 studies carried out in 2015 and 2016 by McShefferty which consider the ‘just noticeable difference’ in speech to noise ratio and points out that there is no benchmark for what is a ‘just noticeable difference’ in speech to noise ratio (SNR). The studies suggested that noise reduction schemes might need to achieve a benefit of greater than 3 dB to be reliably discriminable. In the later paper, the ‘just meaningful difference’ in SNR was considered. They found that the mean difference for more clinically relevant tasks was 6-8 dB regardless of hearing ability.
However, on the facts of this case, HHJ Bidder QC, rejected these findings as unhelpful, he said at para 50:
‘Mr Singh, at page 119 criticises the limitations of the 2 studies – and I do not believe that Professor Lutman has disputed those limitations, but, in my judgment, more significantly, he contends that if those papers are accepted, all I am able to conclude is that 3 dB and 6 dB are likely to be of significance in terms of just noticeable and just meaningful levels in terms of speech to noise rations when considering a relatively broad speech spectrum. Here, however, it is not in dispute between the experts that there is a binaural noise loss of 11.2dB averaged at 3 and 4 kHz and, even accepted the McShefferty research that cannot be regarded as insignificant’.
As a result, the judge concluded that:
‘In my judgment, there is support in the Coles 2000 paper for taking an average of 2,3 and 4 kHz to assess NIHL in certain circumstances and I prefer the conclusions of Mr Singh to those of Professor Lutman in relation to the correct anchor point, for reasons I have given above. There is agreement between the experts that there is an 11.2 dB NIHL averaged binaurally at 3 and 4 kHz and I consider the weight of the expert evidence favours that as being likely to cause a material and appreciable difference for this claimant in both audibility of sound and resolution of speech. In particular, I prefer the clinical experience of Mr Singh, who is used to seeing the effects of such sensorineural loss on patients he treats’.
It was found therefore that the claimant had proved, on a balance of probabilities, that the noise he was exposed to during his employment with the defendants contributed to the NIHL and it made a material, significant and appreciable difference to his capacity to hear and understand sounds. Therefore, he said, the damage was ‘unquestionably compensable’. Applying the JC Guidelines for NIHL, the judge categorised the claimant’s hearing loss as moderate but towards the bottom of the bracket and as there was no tinnitus, the award for general damages was £7,500. As to the need for hearing aids, an award of special damages was made in the sum of £4,067.49. The total award of damages was therefore £11, 567.49, this was apportioned so that the first defendant was liable for the sum of £1,272.42 and the second defendant for £4,279.97.
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Conclusion
We predicted in our guide to the new LCB Guidelines (2016) (here), that as these guidelines were adopted, de minimis arguments would become an increasing feature of NIHL claims. In this Guide, we analysed some 10,000 audiograms and the impact of the LCB Guidelines was that around 50% of claims broadly fell within a de minimis categorisation.
So what can be taken from this most recent judgment?
Whilst there is nothing in this judgment which specifically rejects the LCB Guidelines (2016), and the use of the frequencies of 1, 2 and 3kHz are still the norm – it is fair to say that Professor Lutman’s concession, in which he appears to accept Mr Singh’s suggestion that the logical problems with the LCB guidelines could be avoided by assessing the binaural loss at 2, 3 and 4 kHz, was detrimental to this case.
It is likely that in future cases where there is a loss at 4kHz, that this argument and studies in support will be utilised by claimants, however, this does not alter the fact that quantifying hearing loss over 1, 2 and 3 kHz and its impact on hearing remains the usual approach.
Hearing Loss on the London Underground (BCDN Edition 217)
Research, analysed by the University College London Ear Institute, has sought to discover whether noise levels on the London Tube network are capable of inflicting hearing loss on passengers.26 Previously, in edition 215 of BC Disease News (here), we reported on noise exposure from various transport methods in Toronto, where research concluded that mean noise levels were within recommended safe levels, although cumulative bursts of loud noise still had the potential to place individuals at risk of hearing damage.
In this latest study, the BBC spent one week recording sound levels in zones 1 and 2 of the London tube network.
Findings showed that, on average, the Victoria, Jubilee and Northern Lines were loudest, exceeding 85 dB, and would require hearing protection if they were places of occupation in excess of 8 hours per day. The UCL Ear Institute described this as ‘concerning’, and further said:
‘If someone was on a noisy Tube line every day for long journeys, it is perfectly possible this could increase the risk of hearing loss and potentially tinnitus’.
The loudest noise reading was registered between Liverpool Street and Bethnal Green at 109 dB. During 10 journeys, noise levels were seen above 105 dB as shown in the graphics below.
26 Gareth Furby, London Underground noise could damage hearing, says academic (19 January 2018 BBC London)
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Arranged by average noise level, the loudest journeys were:
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Peter Rogers, of the Institute of Acoustics, has urged TfL to introduce ‘quieter carriages’, as a means to tackle the risk of hearing loss for commuters.
Nigel Holness, of Transport for London (TfL), responded to the findings by stating that:
‘While customers travelling on our network can experience noise, higher volumes tend to be for short periods of time and Health & Safety Executive guidance on noise suggests it is highly unlikely to cause any long-term damage to customers' hearing.
We are confident that nobody out there is exposed to an unsafe nose level. Of course, there are parts of the network that are noisier than others, but you would need to be exposed to that noise for a significant period of time for it to cause you any hearing damage. One of the things we are doing of course is to look at things like quieter track fastenings, we grind the rails, we replace the rails, all of that is designed to give a smoother journey, but also a quieter journey’.27
Hearing Loss in American Agriculture, Forestry, Fishing and Hunting Sectors (BCDN Edition 221)
A new study from the USA involved investigation of hearing loss in workers in the Agriculture, Fishing, Forestry and Hunting (AFFH) sectors28. This is the first study to estimate prevalence and risk of hearing loss for sub-sectors within the AFFH sector29.
Audiograms from 1.4 million workers, of which 17,299 were in the AFHH sectors, were examined between 2003 and 2012. Over all sectors combined, the prevalence of hearing loss was 19%, and the prevalence among the AFFH sector overall was lower, at 15%. However, some sub-sectors had higher prevalence of hearing loss, such as forest nurseries and gathering of forest products, with a prevalence of 36%, timber tract operations, with a prevalence of 22%, and fishing, with a prevalence of 19%.
‘While we found the overall prevalence of hearing loss in the AFFH sector to be less than all industries combined, which is 19 percent, our study shows there are many industries within the sector that have a large number of workers who have or are at high risk for hearing loss,’ said Elizabeth Masterson, PhD, epidemiologist and lead author of the study. ‘Workers in the high-risk industries identified in this study would benefit from continued hearing conservation efforts.’30
Section 33 Discretion in NIHL Claims: Carr v Panel Products Limited [2018] EWCA Civ 190 (BCDN Edition 222)
In this article, we discuss the recent Court of Appeal judgment in Carr v Panel Products Limited [2018] EWCA Civ 190, concerning limitation under the Limitation Act 1980. The claimant appealed the first instance judge’s decision not to extend the 3 year limitation period afforded by the Limitation Act 1980.
The claimant brought a claim 32 years after the end of his employment, issuing the Claim Form on 29 August 2013.
Facts
The claimant was employed by the Defendant (Panel Products) between 1974 and 1981. The defendant was the manufacturer of flat pack furniture and was involved working with wooden materials. He stated that, during the
27 ‘Inside Out London’ (29 January 2018 BBC iPlayer)
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course of his employment, he was unaware that noise could be injurious to hearing and only realised this by (perhaps) his late 30s, between 1984 and 1994.
Even though the claimant was just 51 in 2007, he attributed his hearing lose to ‘old age’.
However, in late 2010/early 2011, the claimant attributed his hearing loss to his work because he had seen a flyer advertising Noise Induced Hearing Loss claims.
First Instance Decision
The limitation period is three years. Under s.11(4), the date from which the limitation period begins is either the date of the cause of action or the date of knowledge (if later). In NIHL claims, the relevant date will usually be the date of knowledge.
Pursuant to s.14 of the Limitation Act 1980, counsel for the claimant argued that the claim was within the limitation period. The date of knowledge is defined in s.14(1), as follows:
The judge at first instance, DJ Jenkinson, ruled that the actual date of knowledge was 2007/08. Adopting Dame Janet Smith’s approach in Johnson v Ministry of Defence [2012] EWCA Civ 1505, constructive knowledge was deemed to be one year post-actual knowledge. As such, at paragraph 23, he decided:
‘Applying an actual date of knowledge of 2007/2008 the claim should have been issued by 2010/2011. Applying a constructive date of knowledge of 2008/2009 the claim should have been issued by 2011/2012. On any basis, given my findings as to date of knowledge, this claim has been issued outside of the limitation period, and is accordingly statute barred by reason of the 1980 Act’.
In the alternative, counsel for the claimant submitted that the judge could exercise his discretion under the list of statutory factors in s.33(3) of the Limitation Act 1980:
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At first instance, the judge ruled, at paragraph 22:
‘... the claim had been issued between one and three years late and that that delay had been unexplained. He considered that the defendant's audiology evidence would have been more cogent had it been undertaken earlier; he noted that Mr Carr's expert contended that his audiometry was more accurate than that of Panel's expert for a number of reasons, some of which would not have been open to him if Panel's expert had been instructed earlier. The judge considered that, even after Mr Carr clearly knew that his problem might be attributable to his work for Panel, there were delays in instructing the medical expert and in the commencement of proceedings to restore Panel to the register; these delays were unexplained.’
The Decision on Appeal
Lord Justice McCombe heard the appeal trial. The claimant’s first ground of appeal was in relation to s.14 of the Limitation Act 1980:
‘…the judge [at first instance] fell into the same error as the judge in Johnson (supra), identified in paragraph 18 of the judgment in this court in that case, in finding that Mr Carr had the relevant knowledge in 2007/8 because he knew (a) that he had hearing loss; (b) that noise could cause hearing loss; (c) that he had been exposed to noise; and thus (d) that his hearing loss had been caused by such exposure. As Johnson's case shows, one cannot jump to point (d), simply because points (a) to (c) are satisfied.’
However, McCombe LJ, in his judgement, upheld the decision of the first instance judge. DJ Jenkinson was correct in his finding of actual knowledge (2007/08), as he had the full evidence before him.
Counsel for the claimant then argued that the judge at first instance was wrong in his finding on constructive knowledge.
On the contrary, McCombe LJ reasoned, at paragraph 38:
‘… the judge [at first instance] was quite entitled to reach the view that he did as to what Mr Carr would have learnt at the hypothetical GP appointment which Mr Carr accepted could easily have been had [and] … It seems to me that his situation is indistinguishable for practical purposes from that of the claimant in the Johnson case’. Subsequently, McCombe LJ moved on to consider the claimant’s appeal concerning s.33 of the Limitation Act 1980. Claimant counsel argued that the judge at first instance had not taken into account ‘… the failure by the judge to consider prejudice to Mr Carr, presumably owing to the passage of time in conduct of the proceedings and in the potential loss of his claim’, pursuant to s.33(1)(a) of the Limitation Act 1980:
Counsel for the Defendant, however, submitted that prejudice, under s.33(1), relates ‘exclusively, or at least mainly’ to the prejudice caused by loss of the claim, as opposed to general prejudice to litigation. Nevertheless, McCombe LJ, at paragraph 46, indicated that prejudice ‘does not need to be expressly raised by a claimant in pleading or argument’ and went on to state, at paragraph 48:
‘As I have said already, potential prejudice to a claimant by the loss of his or her claim is the universal consequence of a claimant losing a limitation argument. Further, the Master of the Rolls said in paragraph 42(3) of his judgment in Carroll (supra) that the burden was on the claimant to show that his or her prejudice would outweigh that to the defendant. This must presume that factors of prejudice, beyond mere loss of the claim itself, can be advanced by a claimant in argument on the application of section 33 in any given case in order to satisfy that burden’.
He continued, at paragraph 49, to say:
‘However, in my judgment, I do not consider that the judge can be faulted on this aspect of the case. This is simply because Mr Carr did not raise, either in his pleadings or in his evidence, any specific issue of prejudice caused to him by the passage of time to meet the burden that was on him in this respect’.
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At paragraph 82 & 83 of the judgement, McCombe LJ dismissed the appeal:
‘In my judgment, on overall consideration of the judge's decision, I do not consider that he went outside the bounds of his reasonable discretion in the matter’.
‘If and in so far as any criticism can by properly levelled at the judge's decision, I consider that this court could properly re-make the section 33 decision and should reach the same conclusion as did the judge. In my judgment, the cumulative features of this case to which I have already referred in this judgment, excluding the factor relating to the audiometry results, added in by the judge of his own initiative, amply justified his conclusion not to exercise discretion in Mr Carr's favour’.
The full text judgment can be here.
Link Between Syphilis and Hearing Loss? (BCDN Edition 223)
‘Increased awareness of the role of syphilis in ear disease has been raised within the sexual health community, but this awareness has not been reflected among ENT specialists.’31
Syphilis is an infection caused by Treponema pallidum bacteria. It is usually transmitted sexually (acquired syphilis), and can also be passed from a pregnant mother to the offspring (congenital syphilis). Since the late 1990s, there has been a sustained increase in the numbers of syphilis cases in England, particularly in London3233.
Syphilis is divided into stages. These are: • Primary syphilis: symptoms are sore(s) at the original site of infection, which usually appear 10-90 days after infection (average around 3 weeks); • Secondary syphilis: various symptoms appear 4-10 weeks after the primary stage, or around 3 months after infection; • Latent stage: bacteria are still present in the body, but there are no signs or symptoms. This stage can last for years; • Tertiary syphilis: The heart, brain, nerves, liver and other organs can be affected. Can appear 10-40 years after infection was first acquired.
Relationship Between Syphilis and Hearing Loss, Otherwise Known as Otosyphilis
Congenital syphilis can be a cause of hearing loss in children. In this article, however, we will focus on acquired syphilis, causing hearing loss in adults.
Both secondary and tertiary acquired syphilis may cause sensorineural hearing loss, and some research papers explain the mechanism by which this can occur34. Late stage otosyphilis, whether acquired or congenital, can
31 Phillips, J. S., Gaunt, A. & Phillips, D. R. Otosyphilis: A Neglected Diagnosis? Otology & Neurotology 35, 1011 (2014). https://journals.lww.com/otology-neurotology/Citation/2014/07000/Otosyphilis__A_Neglected_Diagnosis_.14.aspx (Accessed 12 March 2018) 32 Recent epidemiology of infectious syphilis and congenital syphilis. Public Health England. Infection Report 7 (44). 1 November 2013. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/336760/hpr4413_sphls.pdf (Accessed 12 March 2018) 33 Syphilis epidemiology in London. Public Health England. 17 August 2016. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/547072/london_syphilis_report.pdf (Accessed 12 March 2018) 34 Nadol, J. B. Hearing loss of acquired syphilis: diagnosis confirmed by incudectomy. Laryngoscope 85, 1888–1897 (1975). https://www.ncbi.nlm.nih.gov/pubmed/1195972 (accessed 12 March 2018)
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present up to 50 years or more after exposure35. Diagnosis of hearing loss, caused by syphilis, tends to be made when other causes of hearing loss can be excluded and a patient’s blood tests are positive for syphilis36 37 38.
Patients whose syphilis has caused hearing loss are also likely to have other manifestations of syphilis and may also have tinnitus39. In a 1983 study, it stated that40:
‘… the greatest number of hearing disturbances occurred in persons suffering from general paresis, 65 % were affected’.
[Paresis is inflammation of the brain in tertiary syphilis, causing disorders, such as dementia and paralysis.]
In 2007, Yimtae and colleagues published a review of 85 patients with positive blood test results and cochleovestibular symptoms. It was assumed that all patients had acquired syphilis. 90.6% had hearing loss, 72.9% had tinnitus and 52.9% had dizziness. After treatment, hearing results were improved or stable in 93.4% and 83.3% in the short and long-term, respectively41.
Hearing loss caused by syphilis is one of the few types of sensorineural hearing loss which may be reversible. In a 1983 study, by Dobbin and Perkins, long-term treatment was successful in 15% of 13 patients42. A 1992 study, by Gleich, found that, among 18 patients with cochleovestibular dysfunction of unknown etiology and positive syphilis serology, who were treated with intravenous penicillin and corticosteroids, hearing improved in 5 of 16 patients (31 %). Further, tinnitus decreased in 11 of 13 (85 %) and vertigo improved in 6 of 7 (86 %)43.
Characteristics of Hearing Loss Caused by Syphilis
Both ears may be affected simultaneously, or at different times44. According to a recent commentary45:
‘Otosyphilis should be considered in all patients who present with sudden sensorineural hearing loss, a fluctuating sensorineural hearing loss, and recurrent or persistent vestibular symptoms’.
In the Yimtae study, 75.3% of patients had gradual onset. The duration of symptoms was between 1 day and 20 years (mean 2 years). Hearing loss was usually bilateral, and could be either symmetrical (42.4%) or asymmetrical (32.9%)46.
In a study of 38 patients with cochleovestibular dysfunction and no cause other than syphilis, there was no pattern of dysfunction. Sensorineural loss was bilateral in 82% and unilateral in 18%. This study also found that the impairment was lesser in the first 5 years of hearing loss, and was similar throughout the second to fifth decade affected47.
35 Phillips, J. S., Gaunt, A. & Phillips, D. R. Otosyphilis: A Neglected Diagnosis? Otology & Neurotology 35, 1011 (2014). https://journals.lww.com/otology-neurotology/Citation/2014/07000/Otosyphilis__A_Neglected_Diagnosis_.14.aspx (Accessed 12 March 2018) 36 Becker, G. D. Late Syphilitic Hearing Loss: A Diagnostic and Therapeutic Dilemma. The Laryngoscope 89, 1273–1288 (1979). http://onlinelibrary.wiley.com/doi/10.1002/lary.1979.89.8.1273/full (Accessed 12 March 2018) 37 Hughes, G. B. & Rutherford, I. Predictive Value of Serologic Tests for Syphilis in Otology. Ann Otol Rhinol Laryngol 95, 250–259 (1986). http://journals.sagepub.com/doi/abs/10.1177/000348948609500308 (Accessed 12 March 2018) 38 Bradshaw, D., Pallawela, S., Nelson, M., Scott, C. & Day, S. Otosyphilis: missed opportunities for early treatment? Sex Transm Infect 88, 573–573 (2012). http://sti.bmj.com/content/88/8/573.short (Accessed 12 March 2018) 39 Singh, A. E. & Romanowski, B. Syphilis: Review with Emphasis on Clinical, Epidemiologic, and Some Biologic Features. Clin. Microbiol. Rev. 12, 187–209 (1999). http://cmr.asm.org/content/12/2/187.full. (Accessed 12 March 2018) 40 Schröder, M., Prange, H. W. & Bartels, J. [Hearing and equilibrium disorders in patients with neurosyphilis]. HNO 31, 117–122 (1983). http://europepmc.org/abstract/med/6853226 (Accessed 12 March 2018) 41 Yimtae, K., Srirompotong, S. & Lertsukprasert, K. Otosyphilis: a review of 85 cases. Otolaryngol Head Neck Surg 136, 67–71 (2007). http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.828.4687&rep=rep1&type=pdf (Accessed 12 March 2018) 42 Dobbin, J. M. & Perkins, J. H. Otosyphilis and hearing loss: Response to penicillin and steroid therapy. The Laryngoscope 93, 1540–1543 (1983). http://onlinelibrary.wiley.com/doi/10.1288/00005537-198312000-00003/full 43 Gleich, L. L., Linstrom, C. J. & Kimmelman, C. P. Otosyphilis: A diagnostic and therapeutic dilemma. The Laryngoscope 102, 1255–1259 (1992). http://onlinelibrary.wiley.com/doi/10.1288/00005537-199211000-00010/full (Accessed 12 March 2018) 44 Ibid Nadol 1975 45 Ibid Philips 2014 46 Ibid Yimtae 2007 47 Steckelberg, J. M. & Mcdonald, T. J. Otologic involvement in late syphilis. The Laryngoscope 94, 753–757 (1984). http://onlinelibrary.wiley.com/doi/10.1288/00005537-198406000-00005/full (Accessed 12 March 2018)
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In a 1992 article, ‘On syphilis and the ear – an otologist’s view’, it is noted that, in secondary or early syphilis48:
‘…at some stage the patient presents with tinnitus and deafness, usually bilateral, developing rapidly over a day or two’.
This article also reported that the hearing loss is high tone, and that congenital syphilis, affecting the ear, is more common in younger females, while acquired syphilis is more common in older males. The following observations of the pattern of hearing loss are made:
‘The deafness in late congenital syphilis is usually symmetrical while in late acquired disease it is often asymmetrical and may remain unilateral for months or years. The onset with tinnitus is sudden in 20% of cases and the symptoms fluctuate in 30%, especially the distortion and discrimination. Within the first two years of onset the pure tone hearing loss, as in Meniere’s disease, is low or low plus high-tone. As deafness progresses the loss becomes high tone and finally subtotal to total’. The article goes on to say:
‘The rapidity of progression is variable. Within the first 5 years of ontological manifestation the hearing loss may be as little as 50 dB or as great as 120 dB’.
Some sources suggest that sudden hearing loss is more typical of syphilis infection. In the 2014 European Guideline on the Management of Syphilis, it is mentioned that a patient suspected of early neurosyphilis might have unexplained sudden deafness. In the section of the report that deals with diagnosis, under the heading: ‘Investigation for auricular syphilis’ is the statement:
‘Any patient with unexplained sudden hearing loss should be screened for syphilis’.
The report also makes recommendations for treatment of auricular syphilis49. Furthermore, a 2005 review of syphilis and immune disorders of the inner ear notes that50:
‘The clinical course of the early acquired and late congenital forms are similar: sudden or rapidly progressive bilateral sensorineural hearing loss with mild vestibular symptoms’.
In addition, a 2011 case report of a patient with sudden unilateral hearing loss and tinnitus, caused by syphilis, notes that hearing loss may be unilateral or bilateral; usually progresses rapidly; and may have a sudden onset. Additionally, the report notes that syphilis should be considered in patients with sudden sensorineural fluctuating hearing loss51. A similar case report, in which the patient developed bilateral hearing loss over the course of a week, also comments that sudden-onset hearing loss can be caused by syphilis52.
What Proportion of Hearing Loss is Due to Syphilis?
There is little information available that addresses this question. A 1978 study by Zoller was an investigation into 306 patients with sensorineural hearing loss, in order to determine how many had hearing loss due to syphilis. 20 of the hearing loss patients (6.5%) tested positive for syphilis, compared to 2 out of the 100 subjects in the control (without hearing loss) group (2%)53. All that can be concluded from this is that up to 6.5%, but probably less, of hearing loss is caused by syphilis.
48 Morrison, A. W. On syphilis and the ear--an otologist’s view. Genitourin Med 68, 420–422 (1992). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1194985/ (Accessed 12 March 2018) 49 2014 European Guideline on the Management of Syphilis. International Union against Sexually Transmitted Infection. 2014. https://www.iusti.org/regions/Europe/pdf/2014/2014SyphilisguidelineEuropean.pdf (Accessed 12 March 2018) 50 García-Berrocal, J. R. et al. Otosyphilis mimics immune disorders of the inner ear. Acta Oto-Laryngologica 126, 679–684 (2006). https://www.tandfonline.com/doi/abs/10.1080/00016480500491994 (Accessed 12 March 2018) 51 de Goffau, M. J., Doelman, J. C. & van Rijswijk, J. B. Unilateral sudden hearing loss due to otosyphilis. Clin Pract 1, (2011). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3981434/ (Accessed 12 March 2018) 52 Cassilde, A.-L., Barnaud, G., Baccar, S. & Mortier, E. Sudden-onset bilateral deafness revealing early neurosyphilis. Eur Ann Otorhinolaryngol Head Neck Dis 131, 389–391 (2014). https://www.sciencedirect.com/science/article/pii/S1879729614000611 (Accessed 12 March 2018) 53 Zoller, M., Wilson, W. R., Nadol, J. B. & Girard, K. F. Detection of Syphilitic Hearing Loss. Arch Otolaryngol 104, 63–65 (1978). https://jamanetwork.com/journals/jamaotolaryngology/article-abstract/607115 (Accessed 12 March 2018)
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A 1986 study, by Hughes, investigated whether false-positive results can occur, leading to misdiagnosis. In this study, of 5,439 patients with otologic complaints, 31 were diagnosed as having otologic syphilis. Based on the general prevalence, only 22% of otologic patients who test positive actually have otologic syphilis54. One might also ask in what proportion of syphilis cases that deafness is found. It has been claimed that evidence of sensorineural hearing loss may be found in as many as 17% of early syphilis cases55. Following the resurgence of syphilis in the UK, unusual manifestations, such as otosyphilis, are likely to become increasingly common56.
Sources of information about syphilis tend to mention hearing loss as a possible symptom, but hearing loss sources may or may not mention syphilis as a possible cause. This suggests that syphilis may not be considered a major source of hearing loss.
Among sources of information easily available to the public, some sources list hearing loss among the symptoms of syphilis, such as the European Guidelines on Management of Syphilis57. In some sources, such as the UK National Guidelines on the Management of Syphilis 2015, clinical features of early, latent and late syphilis are described, and hearing loss is only briefly mentioned58. The NHS website lists symptoms of syphilis and does not specifically mention hearing loss, though meningitis, which can cause hearing loss, is listed59. A Fact Sheet from the Centers for Disease Control and Prevention (CDC) describes the symptoms of the stages of syphilis with no mention of hearing loss60.
Sources of information about hearing loss may list syphilis as a potential cause, with little further information, though some sources do not mention syphilis (e.g. NHS website61). Some sources only mention a link between hearing loss and syphilis, in the case of congenital syphilis (e.g. World Health Organisation62). The website, hear-it.org, indicates that: ‘Viruses associated with sudden hearing loss include mumps, measles, rubella, as well as meningitis, syphilis and AIDS…’63 Further, a search for ‘syphilis’ on the Action Hearing Loss UK’s website yield’s no positive result.
Conclusion on All Available Evidence
It seems to be accepted that syphilis can cause hearing loss, but it is probably a minor cause of hearing loss, as some hearing loss sources do not mention it. However, it may be that there is a lack of awareness of syphilis in the ENT field, due, in part, to the lack of studies which attempt to determine what proportion of hearing loss is caused by syphilis. A number of reports note that the diagnosis of hearing loss, due to syphilis, is made when there is no other obvious source of hearing loss. In many case reports, in which hearing loss is attributed to syphilis, the hearing loss has developed rapidly or suddenly. However, when the literature as a whole is considered, it seems that otosyphilis does not follow any particular pattern.
54 Hughes, G. B. & Rutherford, I. Predictive Value of Serologic Tests for Syphilis in Otology. Ann Otol Rhinol Laryngol 95, 250–259 (1986). http://journals.sagepub.com/doi/abs/10.1177/000348948609500308 (accessed 12 March 2018) 55 Ibid Singh 1999 56 Jeans, A. R., Wilkins, E. G. L. & Bonington, A. Sensorineural Hearing Loss Due to Secondary Syphilis. Int J STD AIDS 19, 355–356 (2008). http://journals.sagepub.com/doi/abs/10.1258/ijsa.2007.007221?journalCode=stda (Accessed 12 March 2018) 57 2014 European Guideline on the Management of Syphilis. International Union against Sexually Transmitted Infection. 2014. https://www.iusti.org/regions/Europe/pdf/2014/2014SyphilisguidelineEuropean.pdf (Accessed 12 March 2018) 58 UK national guidelines on the management of syphilis 2015. Kingston, M. et al. UK national guidelines on the management of syphilis 2015. Int J STD AIDS 27, 421–446 (2016). https://www.bashhguidelines.org/media/1053/syphilis-2015.pdf (Accessed 12 March 2018) 59 Syphilis Symptoms. NHS Choices. https://www.nhs.uk/conditions/syphilis/symptoms/ (Accessed 12 March 2018) 60 Syphilis – CDC Fact Sheet (Detailed). Centers for Disease Control and Prevention. https://www.cdc.gov/std/syphilis/stdfact- syphilis-detailed.htm (Accessed 12 March 2018) 61 Hearing loss. NHS Choices. https://www.nhs.uk/conditions/hearing-loss/ (Accessed 12 March 2018) 62 Deafness and hearing loss Fact sheet. World Health Organisation. Updated March 2018. http://www.who.int/mediacentre/factsheets/fs300/en/ (Accessed 12 March 2018) 63 Causes of sudden hearing loss. Hear-it.org https://www.hear-it.org/Causes-of-sudden-hearing-loss-1 (Accessed 12 March 2018)
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Study Identifies Potential Hearing Loss Prevention Drugs (BCDN
Edition 223)
A team of researchers, from St. Jude’s Children’s Research Hospital, have discovered medicinal drugs which have the effect of protecting mice and rats from noise, or drug-induced, hearing loss. The findings suggest that drugs which inhibit an enzyme, called cyclin-dependent kinase 2 (CDK2), prevent the death of cells in the inner ear64.
The chemotherapy drug, cisplatin, is used to treat a range of cancers, but causes hearing loss in 50% to 70% of patients. The researchers screened 4,385 drugs for their ability to protect cultures of cochlear cells from cisplatin. 10 compounds, which had a protective effect, were identified, 3 of which were CDK2 inhibitors. 1 of the CDK2 inhibitors, a drug called kenpaullone, was more effective than 4 other compounds currently used in clinical trials for treating hearing loss. Kenpaullone was also effective in protecting adult mice and rats against cisplatin and noise-induced hearing loss.
In the cell experiments, the cells were treated simultaneously with cisplatin and the drug with potentially protective effects. The 10 compounds with the best protective effects were evaluated on cochleae taken from mice. The best compounds were also tested on tumour cells, to see whether they affected the tumour-killing abilities of cisplatin, which they did not.
The top ten compounds were then tested on zebrafish. Kenpaullone was found to protect zebrafish against the hair cell loss caused by cisplatin, though none of the other nine compounds had any protective effect. Kenpaullone was then tested in adult mice and rats. The researchers determined the dose of cisplatin required to cause hair cell loss and hearing loss of 20-40 dB. Then, kenpaullone was injected into one ear of each mouse, while cisplatin was administered two hours later. Hearing ability was examined after 7 and 14 days. After 7 days, all ears had similar hearing loss, and after 14 days, ears treated with kenpaullone had less hearing loss (a reduction in threshold shift of around 10 dB) than untreated ears. Examination of the cochleae revealed that there was loss of outer hair cells in untreated ears, and reduced loss of outer hair cells in kenpaullone-treated ears. The researchers elected to conduct further experiments on a species of rat which exhibited greater cisplatin-induced hearing loss than in mice. In rats, kenpaullone injections into the ear provided complete protection against cisplatin-induced hearing damage at three or four frequencies of 4, 8, 16 and 22 kHz. The difference between kenpaullone-treated and untreated ears was up to 41.7 dB at multiple frequencies. These results provide strong evidence that kenpaullone is a potent protector of ontological damage caused by cisplatin.
The researchers hypothesized that compounds which are protective against cisplatin would also be protective against noise-induced hearing loss, because both types of hearing loss involve similar mechanisms of hair cell death. To investigate whether kenpaullone is also protective of NIHL, they exposed mice to 100 dB of noise in the 8-16 kHz band for 2 hours, and then, immediately afterwards, injected kenpaullone into one ear and a control solution into the other. After 14 days, kenpaullone-injected ears had significantly reduced threshold shifts (i.e. reduced hearing loss) when compared to the untreated ears. Hearing loss was reduced in the 8-16 kHz range, but not in the 32 kHz region. There was less damage in the synapses of kenpaullone-treated ears than in untreated ears. Interestingly, there was no significant protection by kenpaullone under similar conditions when mice were exposed to 106-, 112-, or 120-dB octave band noise.
In additional experiments, mice lacking the CDK2 enzyme were given doses of cisplatin that simulate those used to treat human patients with cancer. After 47 days of treatment, these mice displayed complete protection against cisplatin ototoxicity at 32 kHz. This suggests that the mechanism by which kenpaullone protects from hearing damage is related to lack of CDK2. The mice were also tested for protection against noise injury, and were found to have smaller threshold shifts at 8 kHz at 7 and 14 days after exposure. No protection was observed at any frequency at 106 dB sound level.
Further experiments on cells demonstrated that CDK2 deficiency attenuates the production of reactive oxidative species, which is the mechanism by which cisplatin causes cell death.
64 Teitz, T. et al. CDK2 inhibitors as candidate therapeutics for cisplatin- and noise-induced hearing loss. Journal of Experimental Medicine jem.20172246 (2018). doi:10.1084/jem.20172246 http://jem.rupress.org/content/early/2018/03/06/jem.20172246 (Accessed 8 March 2018)
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In summary, this paper provides evidence, including a possible mechanistic explanation of how kenpaullone treatment or CDK2 inhibition protects against cisplatin-induced cell death. There are still some questions which remain on this issue and hypotheses which require further testing.
The mechanisms appear to differ for noise and cisplatin-induced injury. Exposure to noise at the 100 dB level does not cause hair cell loss, but causes synapse damage which results in hearing loss. It is unclear why kenpaullone treatment conferred protection against noise exposure at 100 dB but not at 106 dB or higher. It may be possible that CDK2 inhibition is more effective at preventing ‘hidden hearing loss’, i.e. hearing loss resulting from synapse changes caused by lower levels of noise. This hypothesis warrants further investigation in mouse models. As 100 dB noise levels are commonly experienced by workers, kenpaullone could have significant clinical application in treating NIHL in humans. Modifications of the treatment regimens, additional optimization of the delivery methods, and structural modification of the compounds could ensure even better results with CDK2 inhibitors in treating hearing loss in humans.
Acoustic Shock: Goldscheider v the Royal Opera House Covent Garden Foundation [2018] EWHC 687 (QB) (BCDN Edition 225)
A musician has been successful at the High Court in claiming damages for acoustic shock, onset by occupational exposure to noise. Goldscheider v the Royal Opera House Covent Garden Foundation [2018] EWHC 687 (QB) is the first instance of success for a musician bringing a claim of this type.65 However, Nicola Davies J, in handing down judgment, said it is ‘not uncommon’ for musicians to complain about noise levels and employers have attempted to take precautionary measures to reduce claims associated with hearing loss.
The claimant, a professional orchestral voila player, suffered aural damage during a rehearsal of Wagner’s Ring Cycle at the Opera House, on 1 September 2012. During a rehearsal session, he was positioned in front of 18 to 20 brass instrument players. Although the claimant had played in orchestras throughout his professional life:
‘... the sensation from so many brass instruments playing directly behind him, in a confined area, at the same time at different frequencies and volumes, created a wall of sound which was completely different to anything he had previously experienced.
The lack of space and the proximity of the trumpets to the claimant’s ears meant that he was in the brass section’s ‘direct line of fire’. It was excruciatingly loud and painful. His right ear was particularly painful because the principal trumpet was directed at that side of his head’.
The injury suffered ‘prevented his return to music’. Subsequently, the claimant brought a claim against his employer, the ROH, on the grounds that it had breached its obligations to protect its employees under common law, the Control of Noise at Work Regulations 2005 and other regulations. He claimed to have been exposed to a maximum daily dose of 87 dB(A) and/or a maximum peak sound pressure level of 140 dB(C).
WHAT IS ACOUSTIC SHOCK?
The judge described acoustic shock as ‘an index exposure to any sound or cluster of sounds of short duration but at a high intensity reflects and is consistent with the evidence of the claimant as to the playing of the principal trumpet at or close to his right ear’. It is a ‘relatively new and thus far primarily associated with reports emanating from call centres’. In edition 109 of BC Disease News (here), we examined whether acoustic shock could be directly caused by unexpected noise exposure.
As a result of the ‘newness’ of the condition, ‘Mr Jones, the defendant’s expert who retired from clinical practice some five and a half years ago, was dismissive of the concept’.
65 Nick Hilborne, ‘High Court: Viola player can claim damages for “acoustic shock”’ (3 April 2018 Litigation Futures)
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Irrespective of this, the judge did not ‘regard the absence of reported cases of acoustic shock amongst professional musicians as being determinative on this issue of causation. Medical learning and knowledge is an evolving concept.
The injury was consistent with the fact that ‘the sound or sounds would have been unexpected because the claimant had only his own musical part in front of him, the trumpet player had his own part’.
COULD THE DEFENDANT BE EXPECTED TO TAKE PREVENTATIVE ACTION FOR ACOUSTIC SHOCK?
Until Goldscheider, there had never been a case of acoustic shock brought by a music industry employee. As such, the ‘extensive available guidance’ did not recognise the risk of acoustic shock.
Davies J, at paragraph 170, explained the defendant’s position, namely that it ‘should reasonably have been governed by the risk of established conditions, namely noise-induced hearing loss, associated with long term exposure, or the risk of acoustic trauma, associated with a peak exposure in excess of 135 dB(C)’.
She went on to explain the position of the defendant, that:
‘Exposure at 90 dB(A)Lepd on a daily basis would only be expected to cause a small amount of noise-induced hearing loss after a period of ten years. There was no foreseeable risk of injury posed by such a level of exposure in the context of a single day's rehearsal, particularly when hearing protection was worn’.
In any event, the claimant had been fitted with ‘custom-moulded earplugs’, shortly after joining the ROH, in 2002. Additional foam earplugs, providing enhanced protection, were provided at the entrance to the orchestra pit.
However, finding in favour of the claimant, Davies J concluded, at paragraph 229:
‘I am satisfied that the noise levels at the afternoon rehearsal on 1 September 2012 were within the range identified as causing acoustic shock. The index exposure was the playing of the principal trumpet in the right ear of the claimant whether it was one sound or a cluster of sounds of short duration. It was that exposure which resulted in the claimant sustaining acoustic shock which led to the injury which he sustained and the symptoms which have developed, from which he continues to suffer’.
The full text judgment can be accessed here.
In next week’s feature article, we will look at the ratio of the judge in greater detail, on breach and causation, and consider the potential impact of the decision, which we understand may be appealed.
Smokers at Increased Risk of Hearing Loss at 4 kHz (BCDN Edition 225)
A new study has found that smokers may be at an increased risk of hearing loss, particularly at 4 kHz.66 To the researchers’ knowledge, this is the largest study to date, which has investigated the association between smoking and incident hearing loss. The participants in the study were 50,195 Japanese employees, who were free of hearing loss at the start of the study. Pure-tone audiometry was performed annually, for up to 8 years, to identify hearing loss at 1 kHz and 4 kHz.
In follow up investigations, 3,532 individuals were found to have developed high-frequency hearing loss, and 1,575 developed low-frequency hearing loss.
66 Hu, H. et al. Smoking, Smoking Cessation, and the Risk of Hearing Loss: Japan Epidemiology Collaboration on Occupational Health Study. Nicotine Tob Res doi:10.1093/ntr/nty026 https://academic.oup.com/ntr/advance- articleabstract/doi/10.1093/ntr/nty026/4925604?redirectedFrom=fulltext (accessed 28 March 2018)
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Current smokers were 1.6 times more likely than individuals who had never smoked to develop hearing loss at 4 kHz, and 1.2 times more likely to develop hearing loss at 1 kHz. Further, the risk of both high- and low-frequency hearing loss increased with the number of cigarettes smoked per day. There was a small increase in the risk of high-frequency hearing loss, but not low-frequency hearing loss, among former smokers. The analysis of data from former smokers showed that the risk of hearing loss reduced after stopping smoking, even among those who stopped just 5 years prior to the start of the study.
Consequently, researchers concluded that smoking is associated with increased risk of hearing loss, especially at the higher frequency, in a dose-response manner, and that the excess risk of hearing loss associated with smoking disappears in a relatively short period after quitting. Further research is required to supplement these findings.
Feature: Acoustic Shock: An Update (BCDN Edition 226)
In this week’s feature article, we provide a comprehensive overview of ‘acoustic shock injury', which we previously discussed in edition 109 of BC Disease News (here) and following the widely reported case of Goldscheider v the Royal Opera House Covent Garden Foundation [2018] EWHC 687 (QB) which we briefly examined in last week’s edition (here). We now analyse the ratio on breach of duty and causation in greater detail, before going on to consider the contextual significance and future implications of the High Court’s ruling against the Royal Opera House.
WHAT IS ACOUSTIC SHOCK?
The Condition
‘Acoustic shock injury’ is a term that has been used to describe instances of exposure to sudden, loud, shocking or startling noises, usually in one ear, which may subsequently develop into symptoms, such as: • headache; • tinnitus; • ear pain; • nausea; • a sensation of numbness, pain or burning in the head, neck, jaw, shoulder or arm on the affected side; • a hollow feeling or fluttering in the ear; • vertigo; • poor balance; • anxiety; • hypersensitivity to sound (hyperacusis); • fatigue; and • serious depression.67
‘Acoustic shock’ is not to be mistaken with ‘acoustic trauma’, by which the hair cells of the inner ear are damaged, either by exposure to loud noise over a long period of time, or by an extremely high intensity sound, typically greater than 120 dB. The sound levels associated with ‘acoustic shock’ are lower than those required to cause ‘acoustic trauma’. ‘Acoustic shock’ can also be differentiated from long-term exposure to noise, above 85 dB, post-Noise at Work Regulations 1989, which may amount to a positive finding of NIHL, as a consequence of cochlear damage. Many institutions have attempted to define ‘acoustic shock’ in the past:
67 Acoustic shock. Hear-it.org. https://www.hear-it.org/acoustic-shock (Accessed 4 April 2018).
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International Telecommunications Union European Transmission Standards Institute (1998)
• ‘Any temporary or permanent disturbance of the functioning of the ear, or of the nervous system, which may be caused to the user of a telephone earphone by a sudden sharp rise in the acoustic pressure produced by it’.
HSE Position Paper (2008) • ‘A term used in connection with incidents involving exposure to short duration, high frequency, high intensity sounds through a telephone headset’. • The Paper goes on to state that exposure to acoustic events is not sufficient to cause hearing damage as assessed by conventional methods.
Health Services Australia Group • ‘Acoustic shock refers to the combination of exposure to a brief, sudden, unexpected, high frequency, high intensity sound emitted (the stimulus) and the subsequent symptoms (the response) which can develop’. • ‘Acoustic incident refers to a sudden, unexpected, high-pitched sound of high intensity…’ It is generally accepted that these ‘acoustic incidents’ are unexpected and randomly occurring with a high frequency at between 2.3 kHz and 3.4 kHz and with intensities varying between 82 dB to 120 dB of varying durations.
Affected Industries
In edition 109, our feature article focused on the risk of ‘acoustic shock’ in call centres. Since 1991, major manufacturers have incorporated an acoustic limiter in the electronics of their headsets to meet the requirements of the Department of Trade and Industry (DTI)specification 85/013.
In the UK, limiters ensure that any type of noise above 118 dB is not transmitted through the headset. However, this can increase ‘central auditory gain’, which may render operatives more susceptible to ‘acoustic shock’. Some manufacturers are now bringing 'acoustic shock protection' and 'headset noise limiter' devices to the PPE market. In November of 2004, the Call Centre Management Association released a press statement indicating that 300,000 call centre workers may be victims of ‘acoustic shock syndrome’.
Medical Research
Medical consensus on ‘acoustic shock syndrome’ has not yet been reached, since this is still a new and developing area of research, with few studies. The term is no more than a description of a constellation of symptoms, many of which appear to be ill-defined and unrelated, and with no (as yet) physiological link with exposure.
The concept of ‘acoustic shock’ was introduced by Milhinch, in 2002. His research identified 103 call centre operators who reported unexpected high-pitched sounds.68 The study sought to provide evidence of injury following acoustic incidents, most likely due a neurophysiological phenomenon, with some psychological cause. Results showed it was possible that psychophysical responses were heightened in individuals with pre-existing high levels of stress.
Milhinch went on to report that ‘acoustic incidents’ capable of triggering ‘acoustic shock injury’ are typically brief and are frequently measured at the intensity and frequency ranges specified by the Health Services Australia Group (above).
Elsewhere, in a Danish study, published in 2015, sounds capable of causing ‘acoustic shock’ were identified between 100 Hz and 3.8 kHz, with intensities varying from 56 dB to 100 dB. Nevertheless, the proximity of the sound to the ear is a common factor to onset the condition.69
68 Milhinch, J.C. Acoustic Shock Injury: Real or Imaginary?. 17 June 2002. https://www.audiologyonline.com/articles/acoustic- shock-injury-real-or-1172 (Accessed 4 April 2018) 69 McFerren, D. Acoustic Shock Canadian Audiologist 2 (2) 2015 http://canadianaudiologist.ca/acoustic-shock/ (Accessed 4 April 2018)
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In 2007, a British paper by McFerran and Baguley identified ‘acoustic shock’ as, ‘a recently recognized clinical entity’.70
However, other sources have suggested that symptoms are largely psychological. A 2003 report by Lawton, at the University of Southampton, produced information on symptoms experienced by 18 call centre workers, who were bringing personal injury claims. The report concluded that claims for ‘acoustic shock’ concentrated on symptoms, such as tinnitus and emotional response.71 Whereas, pain, lightheadedness and numbness, all of which may start after the ‘shock’ incident, were not associated with neurological deficit.
In a study, carried out by Parker and colleagues in 2014, the medical notes and occupational health records of 30 ‘acoustic shock’ ‘sufferers’ were examined: • 90% had tinnitus; • 70% had previous oto-pathology; • 63% had psychopathology; and • 17% had head injuries.
It was again concluded that hearing loss was not necessarily a feature of 'acoustic shock syndrome'. There is often little clinical evidence of pathology.72
In the same year, Hooper identified cases of pseudohypacusis (exaggerated or false hearing loss) and suggested that ‘acoustic shock syndrome’ is predominantly psychogenic, due to: • the variation in the nature of the acoustic incident involved; • the presence of noise-limiting technology in the workplace; • the marked variation in time of symptom onset (following the incident); and • the clusters of cases occurring in the same call centre.73
It has been suggested that the physiological basis of 'acoustic shock injury' could be excessive contraction of the muscles of the middle ear.74 Symptoms of ‘acoustic shock’ may be instigated by tonic tensor tympani syndrome: the initial response after an ‘acoustic incident’ is thought to be an exaggerated startle response with contraction of the tensor tympani muscle. Continued contraction of the tensor timpani muscle could generate many of the symptoms consistent with ‘acoustic shock’. McFerren, in a 2015 article, argued that, even though this model has many proponents, there is no robust scientific support thus far.75
Most recently, in a case study from 2017, in which the patient’s middle ear function was assessed, a difference in middle ear function was observed between ears exposed to ‘acoustic shock’ and unexposed ears. The authors reported:
‘This study is the first to provide experimental support suggesting that middle ear muscles can behave abnormally after acoustic shock injury’.76
The study also suggested that middle ear inflammation may contribute towards tinnitus and pain suffered.
70 McFerran, D. J. & Baguley, D. M. Acoustic shock. The Journal of Laryngology & Otology 121, 301–305 (2007). https://www.cambridge.org/core/journals/journal-of-laryngology-and-otology/article/acoustic- shock/E74A174BB4647C93F64C3961EE1AAA50 (Accessed 4 April 2018) 71 Lawton, B. W. Audiometric findings in call centre workers exposed to acoustic shock. Proceedings Institute of Acoustics 25, 249–258 (2003). https://eprints.soton.ac.uk/10756/1/ac_shock.pdf (Accessed 4 April 2018) 72 Parker, W., Parker, V., Parker, G. & Parker, A. ‘Acoustic shock’: A new occupational disease? Observations from clinical and medico-legal practice. International Journal of Audiology 53, 764–769 (2014). https://www.tandfonline.com/doi/abs/10.3109/14992027.2014.943847 (Accessed 4 April 2018) 73 Hooper, R. E. Acoustic shock controversies. J Laryngol Otol 128 Suppl 2, S2-9 (2014). https://www.cambridge.org/core/journals/journal-of-laryngology-and-otology/article/acoustic-shock- controversies/EFB44746D653FB57A1AF71396CB526EC (Accessed 4 April 2018) 74 Westcott, M. Acoustic shock injury (ASI). Acta Oto-Laryngologica 126, 54–58 (2006). https://www.researchgate.net/profile/Myriam_Westcott/publication/6684004_Acoustic_shock_injury_ASI/links/55b961b508 aed621de0867e3/Acoustic-shock-injury-ASI.pdf (Accessed 4 April 2018) 75 Ibid at 3 76 Londero, A. et al. A Case of Acoustic Shock with Post-trauma Trigeminal-Autonomic Activation. Front. Neurol. 8, (2017). https://www.frontiersin.org/articles/10.3389/fneur.2017.00420/full
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‘Acoustic shock’ may gain widespread medically accepted recognition in the future, if testing of otological function can demonstrate a difference between exposed and unexposed ears.
Treatment
In respect of treatment, Westcott reported 4 cases of ‘acoustic shock’, which were treated with sophisticated in-the- ear digital hearing aids, set up to act as electronic filters, compressing all sounds down to the range of conversational speech. The rationale for this approach was that it would protect against dangerous sound levels, while avoiding the risk of overprotection. 3 of the 4 patients treated in this study showed improvement, but is difficult to draw firm conclusions from such a small study.
‘ACOUSTIC SHOCK’ CASE LAW
Woodings v BT (2003, unreported)
The claimants, in Woodings, were employees of British Telecommunications. It was alleged that they had suffered ‘acoustic shock’ by way of ‘aural exposure to loud and shrill electronic noise’ through the headsets or earpieces worn. Each complained of earache, ‘auditory interference and vertigo’. As a consequence, minor personal injury was suffered.
At the time of this action, 160 similar claims were pending across the UK, 30 of which were pending against the defendants.
All 5 claimants reached settlement with the defendants for sums ranging between £500 and £750, without the defendant’s admission of liability on medical causation.
The judge, who was assessing the basis upon which costs should be assessed, stated that ‘acoustic shock’ claimants were on a ‘litigation frontier’, whereby the ‘capacity [of sudden noise] to cause personal injury ... [is] ... not clearly understood’. He advised that, had the claim been pursued to trial, the case would have been allocated to the multi-track where extensive medical, scientific and technical evidence could be adduced.
Macintosh v Clark (High Court, 2010, unreported)
At the High Court, in Macintosh, HHJ Harris QC ruled on liability in a personal injury claim, pursued by a former secretary of the 1st defendant employer, a firm of solicitors.
The claimant purported to have suffered damage to her hearing on 21 April 2005, when an employee of the 2nd defendant conducted a routine check of the alarm. The alarm was turned on for approximately two seconds. During this short time period, the receptionist, who was situated 8 ft away from the device, transferred a call through to the claimant, who heard the ‘loud noise’ through the telephone.
Consequential injuries included earache and a loss of hearing in the affected ear for two weeks, together with persisting tinnitus. Damages were agreed at £13,500, subject to liability.
Mr Andrew Raymond was jointly instructed as the acoustic expert. This was his first ‘acoustic shock’ case and ‘he knew of no other expert who had written an acoustic shock report’.
In his report, he stated that, given the ‘minimal duration’ of noise exposure:
‘Purely in terms of noise exposure it would seem unlikely that the Claimant could have been expected to have suffered permanent hearing damage in the conventional sense’.
However, Mr Raymond did, in his report, consider that the levels of exposure were high enough to engage symptoms of ‘acoustic shock’, which he described as a ‘temporary phenomenon’, which was ‘not well understood’. Unlike NIHL, which involves exposure to high levels of noise over an extended period of time, the effect of ‘acoustic shock’ is ‘not to cause damage to the hearing system, more a reaction of shock as in fright; the muscles of the middle ear go into spasm’.
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Expanding on this definition, he stated that the ‘little known condition’ was ‘almost exclusively a call centre phenomenon through headsets generated by somewhat mysterious and speculative sources within telephone systems’.
As such, he imagined, in his report, that ‘few employers outside of call centres would have any knowledge of acoustic shock. The HSE has little to say on the subject’.
Indeed, the HSE website, when the expert report was written, stated:
Mr Raymond, as part of his own investigations, listened to the sound of the alarm via the telephone and, although the noise noted was ‘horrible’, he suffered no symptoms.
Further, he did not expect that either Defendant would have known much about the problems associated with 'acoustic shock', while also noting that most people ‘think noise is more damaging than it is’. In addition, neither ENT specialist suggested that the claimant’s injuries were a ‘reasonably foreseeable’ consequence of her brief noise exposure.
HHJ Harris ruled, at paragraph 13:
‘I found no evidence that either defendant did know or should have known that any damage to hearing was to be foreseen in the relevant circumstances’.
Goode v Morgannwg (Cardiff County Court, 2013)
In Goode, the claimant brought a claim for personal injuries sustained during the course of her employment at the NHS Direct Wales call centre. On 14 November 2005, it was alleged that when she pressed the conference call button, to initiate a three way conversation between ambulance control, the patient and herself, a ‘"white noise", or high pitched static’ was heard through her headset, which she wore on her right ear. The headset was removed immediately. Pain commenced 50 minutes after the incident. This persisted for one week. Two months post-incident, head-turning caused dizzy spells.
The claim brought, therefore, was in respect of ‘acoustic shock’, which caused ‘ear pain, ear blockage, hearing loss, tinnitus, nausea and dizziness’.
In this instance, the headset had an acoustic limiter of 112.3 dB and the claimant failed to prove that the headset was defective in emitting in excess of the 118 dB telecommunications limit. Nevertheless, in a report, dated 5 April 2007, 51 incidents had been reported over the course of the previous year, with 28 (54.9%) resulting in symptoms. The causes of acoustic incidents were recorded as ‘feedback from cordless and mobile phones; crying babies; barking dogs; fax tones and the loud voices of distressed callers’.
On medical causation, Dr Clayton, the claimant's ENT medical expert analysed the claimant’s audiogram (2005) after the incident, which showed increased hearing loss at 1 kHz and 8 kHz, but not at noise sensitive frequencies between 3 kHz and 6 kHz. Later, right-sided audiometry (2007 and 2008) revealed hearing loss at 2, 3, 4, 6 and 8 kHz and he could not explain the delayed elevation in right sided high frequency thresholds. Since acoustic trauma is usually immediate in effect, Mr Clayton adjusted his opinion to a ‘probable aetiology of acoustic shock with an element of acoustic trauma’.
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Whereas, the defendant’s medical ENT expert, Mr Parker, considered that the claimant had not sustained ‘acoustic shock’, but had instead sustained ‘"acoustic startle", which is not a disease, nor is it caused by injury or damage and which has not produced any long-term symptoms below those lasting a few days’.
The judge weighed up the claimant expert’s evidence to consider the ‘temporal link’ between symptoms and the incident.
Mr Clayton referred to the 2002 Milhinch paper: ‘Acoustic Shock Injury: Real or Imaginary’, as discussed above. Milhinch explained that ‘the primary cause of the injury was an excessive “startle reflex”, initially described as the “tonic tensor tympani phenomenon”, a condition in which it is posited that the tensor tympani muscle is spontaneously active, continually and rhythmically contracting and relaxing’. As a consequence, the stressful nature of ‘acoustic incidents’ is responsible for ‘acoustic shock’.
Mr Clayton also cited the research of Klockoff and Westerberg, which noted that ‘elevated psychic tension seems to be the essential etiologic factor in almost all cases’. Thus, they suggested that ‘more severe and persistent symptoms were experienced in this with repeated acoustic incidents’ and a ‘“conditioned response” was to blame with symptoms persisting from months to years’.
Reviewing the evidence, HHJ Bidder stated that ‘acoustic shock syndrome’ is ‘plainly not experimentally established’. The Milhinch study was not in a peer reviewed journal. However, the defendant’s expert described the condition as having ‘low level evidential value’. The judge identified that he had to ‘consider whether the existence of a medical condition is established on balance of probabilities and not to the extent that scientists would require’. In any event, it was noticeable from the research that persisting hearing loss symptoms were absent from the symptoms of the syndrome.
In making his decision, HHJ Bidder preferred the evidence and conclusions of Mr Parker. He said, at paragraphs 92 and 93:
‘I accept the Claimant was exposed to a loud sudden noise and that for no more than a week following the incident suffered gradually diminishing pain in her left ear which was a normal physiological response (a “startle response”) rather than “acoustic shock” or “acoustic trauma”. On a balance of probabilities I find that the “blocked” sensation, the giddiness, hyperacusis and hearing loss and any pain and other symptoms after the first week following the incident, were unrelated to the incident. I am not satisfied on a balance of probabilities that she has suffered from tinnitus and I do not find that any tinnitus was in any way caused by the incident. Her changing her job was causally unrelated to the incident and she has not suffered any incident related symptoms which have caused any financial loss or disadvantage on the labour market...
I therefore conclude that the Claimant’s claim is for very transient and diminishing ear pain which lasted no more than a week ... I have considered the “Minor Injuries” section in the Judicial College “Guidelines for the Assessment of General Damages in Personal Injury Cases” and I consider that the symptoms would justify an award of general damages of £500’.
THE GOLDSCHEIDER CASE
Facts of the Case
In Goldscheider v the Royal Opera House Covent Garden Foundation [2018] EWHC 687 (QB), the claimant, a professional orchestral voila player, complained of aural damage, following a rehearsal of Wagner’s Ring Cycle at the Opera House (ROH), on 1 September 2012. During the rehearsal session, the viola player was positioned in front of 18 to 20 brass instrument players. The injury suffered ‘prevented his return to music’. He subsequently left the ROH, in July of 2014, after having made real efforts to return to rehearsals and performances in 2013. Although the claimant had played in orchestras throughout his professional life:
‘... the sensation from so many brass instruments playing directly behind him, in a confined area, at the same time at different frequencies and volumes, created a wall of sound which was completely different to anything he had previously experienced.'
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At the High Court, the claimant sought damages for ‘acoustic shock’, onset by occupational exposure to noise. In respect of exposure, it was claimed that:
The lack of space and the proximity of the trumpets to the claimant’s ears meant that he was in the brass section’s ‘direct line of fire’. It was excruciatingly loud and painful. His right ear was particularly painful because the principal trumpet was directed at that side of his head’.
In the claimant’s particulars, he claimed to have been exposed to a maximum daily dose of 87 dB(A) and/or a maximum peak sound pressure level of 140 dB(C).
Unlike the former case authorities, discussed above, Goldscheider had not been exposed to electronically generated white noise through an earpiece or telephone. Therefore, he was the first known musician to bring a claim of ‘acoustic shock’.77
However, Nicola Davies J, in handing down the High Court judgment, said it is ‘not uncommon’ for musicians to complain about noise levels, as proven by employers’ attempts to reduce hearing loss claims by introducing precautionary measures.
The claimant was provided with custom moulded 9 dB earplugs, in 2002, which were fitted by a specialist in Harley Street, while 28 dB foam earplugs were available to the claimant when necessary. During the rehearsal, the 28 dB earplugs had been ineffective in blocking out the ‘very high’ sound levels of the brass instruments.
Further, the ROH had given the clamant training and education in the potential dangers of excessive noise exposure, since August of 2005, as documented in his personnel file.
The Claim and The Defence
The claimant argued that the defendant had breached its obligations to protect its employees under common law, the Control of Noise at Work Regulations 2005 and other regulations. By contrast, the defendant denied breach submitted that the noise produced by the professional orchestra is not a by-product of its activities, but the raw product.
As such, the orchestra, with integral aesthetic and technical demands, would be unreasonably compromised if it were asked to go beyond reasonably practicable steps already taken. Indeed, after the incident was reported, the ROH devised plans to move the horn section to the opposite side of the pit, ‘an enormous artistic compromise’. What is more, the Royal Opera House was built in the 19th Century and offered less flexibility than other modern venues.
Noise Exposure
At Paragraph 11 of the judgment, the noise levels of the afternoon rehearsal were measured and recorded as: ‘i) The average noise level to which the claimant was exposed during the three hours, 15 minutes and 24 seconds representing the total measuring period was 91.8 dB(A)Leq; ii) At such a level the "lower EAV" (an eight-hour average of 80 dB(A)Lepd ignoring the effects of personal hearing protectors) was reached within 0.52 hours; iii) The "upper EAV" (an eight-hour average of 85 dB(A) Lepd ignoring the effects of personal hearing protectors) was reached within 1.6 hours; iv) The "exposure limit value" (an eight-hour average of 87 dB(A) Lepd taking into the effects of personal hearing protectors worn) would have been reached within 2.64 hours if no personal hearing protectors had been worn’.
77 Nick Hilborne, ‘High Court: Viola player can claim damages for “acoustic shock”’ (3 April 2018 Litigation Futures)
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The claimant’s first audiogram, performed by the OH advisor at the ROH, revealed ‘significant deterioration in the high frequencies’ in the claimant’s right ear. He was first diagnosed with acoustic trauma.
Appendix of Medical Literature
As was also the case in Goode, the research of Janice Milhinch (2002) was cited in the in the appendix of medical literature in Goldscheider. This, of course, suggested a range of 82 dB to 120 dB sufficient to cause ‘acoustic shock’.
In addition, the Westcott paper (2006), titled ‘Acoustic Shock Injury’, was referred to. We previewed this research in the ‘treatment’ section of this article. In the abstract of the paper, Wescott stressed the risks faced by call centre staff:
‘Call centre staff using a telephone headset or handset are vulnerable to ASI because of the increased likelihood of exposure, close to their ear(s), of sudden unexpected loud sounds randomly transmitted via the telephone line’. Westcott’s research concluded that:
‘With the rapid growth of call centres around the world, professionals providing tinnitus and hyperacusis therapy are increasingly likely to encounter some or all of the cluster of ASI symptoms in their clients’.
Another source of accepted literature was the McFerran and Baguley paper (2007), which we cited earlier in this article. Here, the authors concluded that ‘acoustic shock’ warranted recognition as a separate condition, as opposed to a subsection of an existing condition.
The appendix of medical literature concluded with the International Journal of Audiology paper: ‘Acoustic Shock: A new occupational disease? Observations from clinical and medico-legal practice’. This was co-written by Mr Parker and weighed up the dearth of medical evidence pre-2014.
Before this, however, the appendix mentions the ‘foremost ENT textbook’, written by Scott-Brown, in which he states that ‘objective hearing loss is rarely a feature of acoustic shock’.
The literature adduced in Goldscheider, therefore, remained consistent within existing case law in conveying, scientifically, that psychological symptoms, stemming from ‘acoustic shock’, are more common than hearing loss. However, since McFerran and Baguley published their paper, ‘acoustic shock’ has no longer been regarded as only affecting call centre workers. This position was adopted by Mr Parker in his later work.
Medical Evidence
At paragraphs 110 to 112, the judge provided a description of ‘acoustic shock’, as follows:
‘Acoustic shock is the mechanism of injury from which the symptoms flow. The injury involves the inner-ear and comprises cellular and/or biochemical changes. There has to be an acoustic incident, the sudden onset of loud noise for which the person is unprepared. This is followed by an acoustic startle, a vestigial innate response to the threat of potential injury. The nature of acoustic shock injury is a physiological response to noise. The ear is over stimulated, it builds up a stock of toxic metabolites and from a physiological response it can move to the infliction of damage. The threshold varies for each individual. The physical response to damage to the ear can comprise deafness, pain, tinnitus or dizziness or a combination of two or more.
The noise would be loud, generally unexpected but something extra was needed to get under the stapedius reflex and the unprepared central nervous system, often in the presence of an individual with anxiety, psychological issues or stress. The unexpected noise was that of the Principal trumpet, who was playing from different music which the claimant would not have seen. The claimant would not be familiar with the music of the trumpet because he would not know the trumpet part. The bell of the trumpet is loud. In rehearsal, how the playing occurs would depend upon the conductor's interpretation. The claimant would not know when the trumpet was about to get loud. In Mr Parker's opinion what had occurred was an index exposure, a cluster of short duration, high intensity sounds which presented to the inner ear. The claimant had not suffered a dramatic shift which would be apparent on audiometric testing, nor a dramatic disruption of function, it was not a hydrops loss’.
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Mr Parker, instructed to act for the claimant, concluded, in his report, that the claimant had suffered ‘acoustic shock’. In doing so, he distinguished the claimant from the ‘psychological overlay’, which had been discussed widely in the scientific literature. Mr Parker, in his evidence, noted noise levels sufficient to cause ‘acoustic shock’ as peak levels of between 90 dB and 130 dB, especially between 120 dB and 130 dB. This represents a slight modification of the Milhinch range.
Mr Jones, instructed to act for the defendant, contested Mr Parker’s analysis of the claimant’s symptoms and initially said, of the 'acoustic shock', that it ‘is basically alleged to occur in unprotected subjects wearing headphones, typically call centre workers, exposed suddenly and unexpectedly to unpleasant and brief loud noise’. After discussions between the ENT experts, Mr Jones arrived at the following determination:
‘In my view there is no causal connection between the rehearsal that day and his symptoms and it is not surprising that they developed during a rehearsal in a professional musician, so could a cold. The real point is that if this were the cause he should have had symptoms long ago.
There is no good evidence that this syndrome [AS] exists. If it does then it is not the cause of Mr Goldscheider's problems for several reasons: • It cannot be the cause of some of his symptoms; • The rehearsal noise is very far from that claimed to cause AS; • AS allegedly does not require a very high noise level; hence • It would have occurred in earlier rehearsals; • Later noise would have cause the symptoms anyway’.
Consequently, Mr Jones reasoned that the claimant was more likely to have been suffering with idiopathic Meniere’s disease. This was refuted by Mr Parker as the claimant was suffering from unilateral symptoms, where Meniere’s contemplates bilateral symptoms. Further, hearing loss had been diagnosed at high frequencies, where Meniere’s was consistent with medium or low frequency hearing loss. Moreover, the claimant had a vestibular cause, ‘acoustic shock’, where Meniere’s is a residual diagnosis. It was also suggested that the fact another viola player had complained of symptoms meant the claimant’s condition was no coincidence, veering towards ‘acoustic shock’.
Submissions on Alleged Breaches of the 2005 Regulations
The claimant submitted that that there had been breaches of Regulation 5 of the 2005 Regulations, namely that statutory risk assessments had not been properly carried out; Regulation 6, having failed to eliminate the noise at source, or reduce exposure to as low a level as is reasonably practicable; and Regulation 7, having failed to create a hearing protection zone in the pit of the orchestra, with appropriate demarcated signage and mandatory uptake of hearing protection, where the noise levels were likely to reach the upper EAV of 85 dB (A); among various other breaches of statutory provisions.
The defendant argued that compelling the wearing of hearing protection throughout rehearsals would have been ‘impractical’ and dosimetry readings showed noise exposure of just 68 dB to 70 dB, In fact the claimant had worn 25 dB earplugs during the loudest periods of exposure. Counsel for the defendant argued that it had taken: ‘… all reasonably practicable steps to reduce the noise levels, the standards to which the defendant's efforts should be held is one of reasonableness not perfection’.
Additionally, defendant counsel invited the court to consider s.1 of the Compensation Act 2006, to counterbalance the duties prescribed by Regulation 6:
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Claimant counsel contested this, at paragraphs 164 and 165:
‘The defendant has advanced no evidence that artistic values of productions of its operas, specifically those in the Ring Cycle, would in 2012 or now be reduced by steps taken to eliminate or reduce noise exposure from that created by the configuration of musicians in amongst whom the claimant was rehearsing on Saturday 1 September. The reliance upon "artistic value" implies that statutory health and safety requirements must cede to the needs and wishes of the artistic output of the opera company, its managers and conductors. Such a stance is unacceptable, musicians are entitled to the protection of the law as is any other worker. The employees are subject to instruction, set rehearsal times and performance hours’.
Conversely, counsel for the defendant cited Sedley LJ in Bhatt v Fontain Motors [2010] EWCA Civ 863:
‘In relation to … the burden of proof in relation to what is reasonably practicable, it may be that there is, and needs to be, no fixed allocation of the burden. It will depend on what has happened and the situation in which it has happened’ [paragraph 39].
Further, in its written submissions, the defendant submitted that, in light of its ‘status as a national institution creating music of the highest quality’:
‘The Court should recognise the great cultural value which the defendant's endeavours have to society and consider this value as being of importance when setting the standard which the defendant should reasonably meet. Some of those most invested in the defendant's endeavours are the musicians. They are partners and stakeholders with the defendant in the pursuit of the highest possible standards, motivated by such concerns as much as the defendant itself. It would be perverse if the imposition of unrealistic standards jeopardised the very enterprise which gives such meaning and satisfaction to the lives of the employees which the standards seek to protect’.
Ruling on Breach of Statutory Duty
Davies J found the defendant in breach of Regulations 5, 6, 7 and 10 of the 2005 Regulations, while s.1 of the Compensation Act 2006 provided no assistance.
Interestingly, at paragraph 205, upon consideration of the defendant’s ‘artistic’ status, the judge said:
‘… I am left with a sense that the ROH's wish to maintain the highest artistic standards and uphold its reputation coupled with the deference accorded to the artistic aims of leading conductors were factors which had the potential to impact upon its obligations pursuant to the 2005 Regulations. However laudable the aim to maintain the highest artistic standards it cannot compromise the standard of care which the ROH as an employer has to protect the health and safety of its employees when at their workplace’.
At paragraph 207 of the judgment, Davies J also rejected the defendant’s argument that a finding of breach, under Regulation 7, was a ‘sterile allegation’. She went on to reason that:
‘The mandatory requirements have been breached. The Regulations recognise no distinction as between a factory and an opera house. As at the date of the claimant's accident a breach of the 2005 Regulations provided a basis for a claim in civil liability. Breaches of Regulation 7(3)(a) and (b) are directly relevant to the instruction given to employees for the wearing of personal hearing protectors in the orchestra pit. This Regulation places a more onerous duty on the employer not only in terms of demarcation but in the context of the signage, the instruction it gives to its employees prior to entering the demarcated area, namely that ear protection must be worn. I find that the management of the ROH had not focused properly or at all on these provisions, the instruction given to its employees did not reflect the stringent requirements of Regulation 7(3)(b)’.
At paragraph 209, the defendant was further penalised for allowing the musicians to judge for themselves when hearing protection was necessary. As such, Davies J concluded that the defendant had failed to ‘properly inform and instruct its musicians as to the imperative nature of the need to wear the protection’ and thus failed to comply with the Regulations.
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Causation Arguments
The position of the defence was that the medical evidence on causation was ‘opaque’. What difference would hypothetical preventative measures have made? According to the scientific literature, 'acoustic shock' can be onset by noise levels as low as 82 dB. If a sound level this low was responsible for the injury, then the injury had been caused absent of negligence. At no point was the claimant able to describe any specific moment when he was ‘shocked or startled by a particular sound’. This omission fuelled the defence in stating that there could be no attribution between the musical performance and the condition.
Ruling on Causation
Providing an overview of the landscape, Davies J reasoned, at paragraph 223, that:
‘The concept of acoustic shock is relatively new and thus far primarily associated with reports emanating from call centres. Mr Jones, the defendant's expert who retired from clinical practice some five and a half years ago, was dismissive of the concept. I do not regard the absence of reported cases of acoustic shock amongst professional musicians as being determinative on this issue of causation. Medical learning and knowledge is an evolving concept. It is the mechanism of acoustic shock and the nature and symptomatology of the claimant's injury which is relevant to the determination of this issue’.
However, the judge continued, in the following paragraph, to justify that:
‘The description of acoustic shock, namely an index exposure to any sound or cluster of sounds of short duration but at a high intensity reflects and is consistent with the evidence of the claimant as to the playing of the Principal trumpet at or close to his right ear. The sound or sounds would have been unexpected because the claimant had only his own musical part in front of him, the trumpet player had his own part. Audiometry following the incident demonstrates changes in the right ear, not reflected in the left ear. I regard the defendant's contention that Meniere's disease developed at the rehearsal as stretching the concept of coincidence too far by reason of: (i) the nature of the index exposure and (ii) the fact that the person sitting next to the claimant described the loud noise of the trumpets and the similar physical effect upon her. The level of noise recorded during the afternoon, in particular the peak levels, would be consistent with those reported in the medical literature as causing acoustic shock’.
As a result, the claimant was successful on medical causation. At paragraph 229, Davies J held:
‘I am satisfied that the noise levels at the afternoon rehearsal on 1 September 2012 were within the range identified as causing acoustic shock. The index exposure was the playing of the Principal trumpet in the right ear of the claimant whether it was one sound or a cluster of sounds of short duration. It was that exposure which resulted in the claimant sustaining acoustic shock which led to the injury which he sustained and the symptoms which have developed, from which he continues to suffer’.
IMPACT OF GOLDSCHEIDER
Goldscheider is the first case to find in favour of ‘acoustic shock’ within the music industry. Even though scientific literature had eluded to the idea that the condition can affect other professions, ‘acoustic shock’ has been predominantly regarded as a call centre worker condition.
On breach of duty, Davies J strictly applied the Regulations, rejecting the defendant’s contention that the Noise at Work Regulations fail not make a distinction between noise generated as a by-product and noise created for enjoyment and entertainment. As such, points raised under s.1 of the Compensation Act and autonomy given to orchestral players were not viewed favourably on assessment of risk mitigation. The threshold for ‘reasonable practicability’ remained high.
On medical causation, the judge leaned in favour of ‘acoustic shock’, even though the medical evidence, attributing the condition to the course of employment was ‘opaque’. In deciding against Mr Jones’ diagnosis of Meniere’s, the finding of ‘acoustic shock’ could be perceived as a finding by process of elimination. As time passes,
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a clearer image of ‘acoustic shock’ will emerge and simultaneously provide clarity on medical causation in disease claims of this type.
The decision is likely to be appealed. However, until the ruling is overturned, there is potential for similar claims to be brought and there seems no reason why these should be restricted to the music or leisure industries.
Feature: Future Hearing Assistance Claims: The McShefferty Papers (BCDN Edition 233)
In the case of Evans v Secretary of State for the Department of Energy and Climate Change and Anor (Unreported, Cardiff County Court, 2017), the judge primarily dealt with expert differences of opinion on quantification of hearing loss where the claimant alleged a loss of speech intelligibility as a result of NIHL. We provided case analysis in edition 216 of BC Disease News (here).
In Evans, the defendant’s medical expert, Professor Lutman, cited the McShefferty papers in his medical report, although the significance of the findings were not considered by the trial judge in detail. Within these papers, David McShefferty investigated how the phenomenon of speech-to-(background) noise ratio (SNR) affects the understanding of speech communication in both hearing impaired and non-hearing impaired individuals.
In this article, we review the conclusions reached and consider any foreseeable impact on future claims for hearing assistance devices.
WHAT IS SNR?
Speech-to-noise ratio (SNR) is the level of speech relative to the level of background noise. It is measured in decibels and is the difference between the sound levels of speech and noise signals. For example, a 2 dB SNR could be achieved by having a 72 dB speech signal in a 70 dB noise signal.
SNR is therefore relevant to our ability to hear and understand speech in the presence of background noise. This is a common admission in claimant witness statements who allege NIHL.
Generally speaking, hearing impaired individuals require higher SNR to achieve the same results in speech intelligibility tests as non-hearing impaired individuals.
Factors that can affect improvements in SNR include distance and spatial location from the speech signal, the type and number of noise sources and the amount of reverberation in the environment.
DO HEARING AIDS AFFECT SNR?
Technically, the function of hearing assistance devices is not to increase SNR. They simply amplify the combined speech and background mixture.
However, some features of hearing aids, such as directional microphones, can produce more favourable SNR for users. As a result, NIHL claimants often seek future hearing assistance.
RELATIONSHIP BETWEEN SNR AND SPEECH INTELLIGIBILITY
Increased SNR and, by deduction, the use of hearing aids, can therefore increase speech intelligibility – but to what extent?
It is important to consider that the magnitude of any increase in intelligibility depends on the difference between subjects’ responses to physical stimuli in testing.
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So, is there a definitive increase in SNR which allows speech clarity to be more ‘noticeable’, or ‘meaningful’? This was the purpose of David McShefferty’s two published papers.78 79
PRE-MCSHEFFERTY PAPERS
Prior to the latest work of David McShefferty & others, in a study conducted by Killion, it was found that a 2 dB increase in SNR could yield benefit. However, the author warned that this change was unlikely to be noticed in a real-world setting.
MCSHEFFERTY PAPERS
The Just-Noticeable Difference in Speech-to-Noise Ratio Experiments
The 2015 study comprised of 4 separate experiments. McShefferty perceived that just-noticeable difference (JND) was crucial to the understanding of how much improvement in SNR is necessary to provide a ‘noticeable’ benefit, i.e. a difference in intelligibility that listeners can detect. He also considered it important to analyse whether there was an association between the degree of hearing impairment and JND. Both of these considerations are relevant to the suitability of claims for future hearing assistance.
Of particular relevance was the 1st experiment, in which 44 participants were recruited (50:50 male to female ratio). Better-ear, four-frequency (at 0.5, 1, 2, and 4 kHz), pure tone average hearing losses were measured. Among the participants, losses ranged from (-) 2 dB to (+) 71 dB. The criteria for hearing impairment was that average loss over all the frequencies exceeded 25 dB in the better ear. Of the 44 participants, 14 were non-hearing impaired and 30 were hearing-impaired. 23 of the 30 hearing-impaired participants had sensorineural hearing loss, 3 had mixed hearing loss and 4 had conductive hearing loss.
The purpose of the 1st experiment was to measure the ‘noticeable’ difference caused by changes in SNR. To calculate JND, test subjects listened to two sentences with different SNRs, containing male-talker sentences partially masked by speech-shaped noise. The sentences were separated by a gap of half a second of silence and the participants were asked to decide: ‘Which sentence was clearer?’ This procedure was repeated, and the difference in the SNR between the two sentences was gradually reduced as the participants correctly identified the sentence with the higher SNR. When the gap between the two SNRs of the two sentences was small enough that the participant had got several answers wrong, the test was completed, and the size of this SNR gap was the JND for that participant.
Among the 44 participants, the average JND for a change in SNR was 3.2 dB.
Non-hearing impaired test subjects gave an average JND for a change in SNR of 2.9 dB.
Hearing-impaired test subjects gave an average JND for a change in SNR of 3.3 dB.
The study authors observed a relationship between age and JND. However, they did not find any difference between the JND measured in hearing-impaired and non-hearing impaired groups. Any difference was not statistically significant. On average, the JND in SNR of speech in noise was 3 dB across all 44 participants.
The authors concluded that, although the conventional level of JND was considered to be 1 dB, they were confident that their measurement was accurate. Further, the authors stated that Killion’s study (referred to above) perceived a 4 dB JND to be 90% correct, compared to a 2 dB JND, which was only 50% correct. Interpolating the JND found in the McShefferty papers, Killion would calculate this finding to be 79% correct.
The significance of the results was phrased, as follows:
78 David McShefferty et al., The just-noticeable difference in speech-to-noise ratio, Trends Hear. 2015 Feb 12;19. pii: 2331216515572316.
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‘The SNR JND of 3 dB measured here indicates the lower bound of the minimal clinically important difference for SNR improvement; that is, a change of 3 dB SNR indicates the threshold of the perceptual relevance (as opposed to speech intelligibility improvement) of those features of hearing aids designed to increase SNR. Therefore, regardless of the strategy used to achieve it, the data presented here indicate[s] that a noise reduction scheme— or directional microphone or indeed any feature for increasing SNR—in a hearing aid should provide at least 3 dB SNR improvement in order to provide a reliable and consistently noticeable benefit for HI listeners’.
The study’s ‘Discussion’ section does, however, consider that the expected JND could decrease if there are ‘changes in listening effort or fatigue, particularly in continuous speech with multiple opportunities for detecting a difference in SNR’. Alternatively, the expected JND ‘might also increase in a real-life scenario with multiple distracters and reverberation present’. Without more rigorous testing, the necessary benefits that hearing assistance devices need to provide are arguably difficult to quantify.
What is more, McShefferty’s findings on ‘noticeable’ difference were no indication of how significant a change in SNR has to be to bring about a ‘meaningful’ difference, obligating medical intervention. This led to the publication of McShefferty’s 2nd paper, in 2016.
The Just-Meaningful Difference in Speech-to-Noise Ratio
In the introduction to the 2016 article, the authors emphasised the importance of carefully distinguishing ‘noticeability’ and ‘meaningfulness’ of changes in SNR.
Just ‘meaningful’ difference (JMD) is the minimum increase in SNR necessary for there to be a medical intervention. This is because JMD strongly resembles clinically important difference (CID). CID is regarded as a ‘change in outcome that would be considered meaningful to a patent after some form of intervention’.
The difficulty with previous investigations involving CID, highlighted by the researchers, is that the perception of beneficial outcome is often not determined by decrease in disease prevalence or statistical inference. Measuring JMD requires a subjective test, not an objective one. JND, investigated in the 2015 McShefferty paper, is objective, i.e. the measurements (in dB) are appreciable to scientists and clinicians, and cannot be influenced by the participants’ opinions. By contrast, JMD relies on the opinions of test subjects.
As a result, the 2016 study was an attempt to reconcile the differences between subjective and objective ratings of hearing ability and perceived benefit.
4 separate experiments were devised to measure ‘the smallest difference in SNR that would elicit a change in behaviour’. We will examine the results of the first 3 experiments conducted.
Participants were recruited and better-ear, four-frequency (at 0.5, 1, 2, and 4 kHz), pure tone average hearing losses were measured.
Once again, test methods involved listening to two intervals (target interval and reference interval), containing a corpus of sentences partially masked by embedded speech-shaped noise. The identical choice in stimuli was deliberately chosen to allow for direct comparison with the earlier JND results.
However, unlike the 1st experiment of the JND paper, the participants in the 1st JMD experiment were not only given a noise discrimination task, but also asked whether the target interval was the same, better, or worse than the reference interval (which was a SNR of 0, so the speech sound level was the same as the background noise level) with an incremental change in SNR. ‘Better’, for the purpose of examination, was defined as ‘being clearer or easier to listen to’. Ratings were measured on an 11-point scale [from (-) 5 (much worse), to 0 (the same), to (+) 5 (much better)]. Of the 32 participants tested, 14 had sensorineural hearing loss and the remainder were non-hearing impaired.
JND for a change in SNR yielded similar results to the 2015 study (3 dB). JND was measured at 2.8 dB across all participants in the 1st experiment of the 2016 paper. On average, benefits were rated as better by 1 unit after a 4 dB increase in SNR and deficits were rated as worse by 1 unit after an 8 dB change in SNR, where units are the
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increments of the 11-point scale from ‘much worse’ to ‘much better’. However, the authors note that it is unclear what ‘one unit’ would mean on a clinical level.
The 2nd and 3rd experiments were designed to give the JMD in SNR measurements more clinical relevance.
In the 2nd experiment, the test subjects listened to sentences with a particular SNR, and then other sentences with a different SNR, were told that the first one was the sound from their device and the second one was the sound from a different device, and asked if they would like to swap devices. The JMD was defined as the threshold (in difference in SNR) at which the participant wanted to swap devices. Of the 31 participants tested, 21 were classified as hearing impaired (3 had conductive loss and 17 had sensorineural hearing loss) and the remainder were non-hearing impaired. Results showed that participants said ‘Yes’ to switching more than 50% of the time when the increase in SNR was between 4 dB and more than 8 (the highest difference tested) dB.
In the 3rd experiment, participants were asked if they would be willing to attend a clinic for a given SNR benefit or deficit, which, again, were presented as pairs of sentences with different SNR’s. Of the 21 participants tested, 10 had sensorineural hearing loss and the remainder were non-hearing impaired. ‘Yes’ responses only exceeded 50% when the increase in SNR was between 6 dB and 8 dB.
As such, the researchers concluded that a meaningful difference equates to an average increase of 6 dB of SNR. Further, a 6 dB JMD ‘means that a change of 6 dB of SNR needs [to] be supplied for someone, on average, to consider it worth seeking intervention, whether by swapping their devices or attending the clinic’.
Moreover, the authors were successful in discovering that there is a difference between ‘noticeable’ and ‘meaningful’ difference in SNR:
‘While participants were able to detect differences in SNR of 3 dB, those differences were not deemed to be clinically important (i.e., participants were unwilling to swap devices or to attend the clinic for differences of that magnitude). Only when differences in SNR reached at least 6 dB did participants find them meaningful enough to consider intervention’.
Many of the limitations discussed in 2015 were also discussed in the 2016 paper. These were discussed in more detail by a co-author of McShefferty papers, William Whitmer, in the run-up to the Evans case.
CRITIQUE OF MCSHEFFERTY PAPERS
In November of 2017, prior to the Evans trial, William Whitmer, co-author of the McShefferty papers, responded to comments made by Professor Mark Lutman in his defendant commissioned medical report and shed light on the continuing limitations of his co-written work.
One limitation discussed, was that the McShefferty papers identify what immediate change in SNR would be ‘noticeable’ or ‘meaningful’. As such, thresholds relevant to the perception of long-term changes in SNR are still ‘unclear at best’.
Mr Whitmer further indicated that, while random variation of sound level from one presentation to the next was designed to rule out the use of sound level as a cue, day-to-day realistic listening situations would not be that unpredictable. Consequently, the JND thresholds are relevant to the demonstration of hearing aid features, such as noise reduction, but not necessarily changes in SNR which bring about a ‘noticeable’ or ‘meaningful’ change of speech clarity.
He also explained that the McShefferty papers measure ‘noticeable’ and ‘meaningful’ difference on the basis of single sentences, before going on to cite data collected in additional, unpublished research, which showed that discriminating changes in SNR for single words was more difficult than discriminating changes in SNR for sentences. Extending that association, he expected that changes in SNR (especially the meaningful thresholds) would decrease with prolonged listening, ‘as occur in daily life’.
In summary, Mr Whitmer concluded:
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‘... it is my strong opinion that the result of the two studies of McShefferty et al. cannot be used to draw valid inferences about the smallest change in audiometric thresholds that would be noticeable in cases of noise-induced hearing loss’.
EVANS V SECRETARY OF STATE FOR THE DEPARTMENT OF ENERGY & CLIMATE CHANGE (2017)
In the case of Evans, the claimant alleged that he had difficulty in ‘several domestic and social situations’. It was said that he struggled to understand ‘... conversation, particularly in the presence of background noise. He not infrequently ... [had] ... to ask others to repeat themselves or to speak up ...’
In this case, causation was disputed. The experts differed in their quantification of hearing loss, i.e. whether the loss was ‘significant or appreciable’. If the NIHL was insignificant, the claimant would not have been able to advance the claim for future hearing aids.
The defendants were assisted by the instruction of Professor of Audiology, Mark Lutman. They submitted that, on the balance of probabilities, the claimant’s noise induced hearing loss should have been treated as ‘de minimis’.
Prior to the case of Evans, in edition 111 (here), we discussed the medical authorities on the effect of NIHL at specific frequencies on speech intelligibility. In Evans, the importance of speech intelligibility at 4 kHz were debated.
The judge found in favour of the claimant expert’s analysis, ruling that the claimant’s calculated losses were ‘likely to cause a material and appreciable difference for this claimant in both audibility of sound and resolution of speech’. Mr Singh, favoured the use of a 4 kHz anchor point, as opposed to a binaural 1, 2, 3 kHz average, suggested in the 2016 LCB guidelines. As such, the claimant’s average binaural NIHL, between 3 and 4 kHz, was calculated at 11.2 dB.
The judge accepted, as a result of the method of NIHL calculation, that ‘the Claimant’s need for hearing aids ... [was] ... brought forwards by 5 years ...’
Unsuccessfully, he sought to use the McShefferty papers to bolster his argument. At paragraph 50 of the judgment, the judge reasoned:
‘Mr Singh, at page 119 criticises the limitations of the 2 studies – and I do not believe that Professor Lutman has disputed those limitations, but in my judgment, more significantly, he contends that if those papers are accepted, all I am able to conclude is that 3 dB and 6 dB are likely to be of significance in terms of just noticeable and just meaningful levels in terms of speech to noise ... [ratios] ... when considering a relatively broad speech spectrum. Here, however, it is not in dispute between the experts that there is a binaural noise loss of 11.2 dB averaged at 3 and 4 kHz and, even ... [accepting] ... the McShefferty research, that cannot be regarded as insignificant’.
CONCLUSIONS
Provided that long-term changes in SNR produce, as McShefferty et al. suggests, a 3 dB JND, the studies dictate that hearing impaired claimants would only ‘notice’ a difference in speech intelligibility if they were to use hearing assistance which increases SNR by at least 3 dB. The same analogy can be extended to intervention- seeking ‘meaningful’ difference, at 6 dB. In the conclusion of the 2016 study, the authors advise:
‘... when the JMD was measured as a participant’s willingness— 50% of the time—to swap devices or attend clinics for a change in SNR, it was approximately 6 dB for more difficult (lower SNR) situations and 8 dB for less difficult situations ... These latter, less arbitrary JMD values exceed what is currently possible with conventional hearing-aid technology’.
If this assertion is correct, and the McShefferty limitations are disproven, then noise reduction schemes in modern hearing aids should be enhanced. If they are not, it is likely that hearing aid users are subjected to speech in background noise which has not received an increase in SNR significant enough to produce a reliably discriminable difference, when compared with non-use.
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Great Ormond Street Hearing Loss Prevention Drug Trials (BCDN Edition 235)
In editions 223 (here) and 184 (here), we reported on studies into hearing loss prevention drugs. Most recently, in issue 223, we reported that enzyme inhibitors were capable of protecting cultures of cochlear cells in cancer patients.80
In the latest investigation on hearing loss prevention drugs, scientists found that long-term side effects of chemotherapy (cisplatin-based) were reduced by a new drug, when taken in combination.
Trials were conducted by Great Ormond Street Hospital to observe the effect of sodium thiosulphate (STS) on hearing loss.
109 children were administered with the drug.
The research team, led by paediatric consultant, Dr Penelope Brock, found that hearing damage was reduced from 63% to 33% in patients, while the risk of hearing loss was reduced by nearly 50% compared with those who had not received STS.
Feature: Hearing Testing Methods Additional to Pure Tone Audiometry (Part 1) (BCDN Edition 235)
INTRODUCTION
In edition 160 of BC Disease News (here), we considered whether a single audiogram, produced by Pure Tone Audiometry (PTA) Testing, is a valid basis for bringing NIHL claims.
We considered the strength of PTA, in light of research, conducted by Southampton University, which stated:
‘Despite being regularly referred to as the "gold standard", pure tone audiometry, as it currently stands, has a very high degree of potential error, particularly in a clinical environment’.
Over the course of the next two weeks, we will be considering alternative scientific clinical methods capable of diagnosing hearing loss:
1. OTO-ACOUSTIC EMISSIONS
Otoacoustic emissions are sounds that originate from vibrations of the cochlea, and are caused by the motion of sensory hair cells in the cochlea as they respond to auditory stimulation. These vibrations occur as a by-product of a cochlear mechanism known as the ‘cochlear amplifier’, which contributes to the sensitivity and discrimination of hearing. During the test, a small microphone is placed in the ear canal. The microphone plays a sound and detects the inner ear’s response to the sound.
80 ‘Drug reduces hearing loss' after childhood cancer treatment’ (21 June 2018 BBC)
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Types of otoacoustic emissions include distortion product otoacoustic emissions (DPOAEs) and transient evoked otoacoustic emissions (TEOAEs). DPOAE testing uses two pure tones that have similar frequencies as stimuli, which combine to generate different frequency components. In response to these tones, outer hair cells generate signals, called distortion products, that are related to the frequencies of the presented tones. TEOAEs uses clicks that cover a range of frequencies as the stimulus. Unlike other hearing tests, it is not necessary for the stimulus to be close to threshold levels to detect departures from normal function, using OAEs.
In TEOAE testing, ‘wide-band’ clicks are generated and these excite the whole of the cochlea. TEOAE responses can give frequency specific information about cochlear function, by splitting the response into frequency bands. TEOAE responses are strongest and easiest to detect in the 1-4 kHz band. In children and babies, TEOAEs extend up to 6-7 kHz, but many clinically normal adult ears give weak TEOAEs (less than 3 dB SPL), with no substantial response above 4 kHz.81 A stimulus clicking sound of around 84 dB SPL will normally evoke a robust TEOAE response, only if the hearing threshold is 20 dB HL or better.82 Frequencies at which hearing thresholds exceed 20-30 dB HL are typically absent in the TEOAE response.
The TEOAE and DPOAE techniques complement each other. DPOAEs offer observation over a wider range of frequencies (up to more than 10 kHz), but have less sensitivity to minor conditions in adults. DPOAEs have been found to provide the most information for detecting mild hearing loss at high frequencies. With moderate hearing losses, DPOAEs may be recorded when no TEOAE can be detected, because the continuous tones used in DPOAE may provide more powerful stimulation to the cochlea than the clicks used in TEOAE. DPOAE analysis is complex and interpretation is difficult. If DPOAEs are present, but TEOAEs are absent, this suggests mild-to-moderate loss only.83
How Reliable Is It?
Although OAEs are a good indicator of hearing loss, an OAE test is not a hearing test; it is a test of cochlear function.84 It is tempting to believe that OAE intensity relates to cochlear ‘strength’, but this is not the case. The presence, or lack thereof, of an OAE response is of clinical importance; the strength is not. In other words, an OAE gives a ‘yes or no’ response at different frequencies of cochlear function. OAEs are frequency-specific, and are seen in frequency bands where hearing is normal.
OAE response intensity can be strongly affected by factors such as the fit of the probe used to record the data and middle ear disorders. Individual healthy ears differ greatly in the level and spectrum of OAEs produced. OAEs provide information about the function of the outer hair cells, and do not evaluate the inner hair cells.85 An advantage of OAE testing over pure tone audiometry is that co-operation from the listener is not required: OAE is an objective test method. A disadvantage is that OAE results can be affected by middle ear status.86
In DPOAE testing, the cochlea status is indicated by the intensity of the different components of the tones. DPOAE generation is much reduced and usually absent if there is significant sensory hearing loss. Measurement of DPOAEs, using a range of stimulus sound levels, can establish OAE ‘growth rate’, i.e. how the intensity of the OAE varies with the intensity of the stimulus. Healthy ears tend to exhibit a DPOAE growth rate of 1 dB of OAE per 1 dB of stimulus or less. Ears with some impairment show steeper growth.
Single DPOAE observations can be misleading and results need to be averaged across a frequency range. It has been suggested that when data from multiple people are grouped together, DPOAEs relate to hearing threshold levels, but in data on individuals, they are a very unreliable and imprecise indicator of hearing thresholds.87 This is
81 Kemp, D. T. Otoacoustic emissions, their origin in cochlear function, and use. Br Med Bull 63, 223–241 (2002). https://academic.oup.com/bmb/article/63/1/223/377500 (Accessed 29 March 2018) 82 Ibid. 83 Ibid. 84 Ibid. 85 Cunningham, R. F. Otoacoustic Emissions: Beyond Newborn Hearing Screening Rebekah F. Cunningham. AudiologyOnline Available at: https://www.audiologyonline.com/articles/otoacoustic-emissions-beyond-newborn- hearing-838. (Accessed: 6th April 2018) 86 Helleman, H. W., Eising, H., Limpens, J. & Dreschler, W. A. Otoacoustic emissions versus audiometry in monitoring hearing loss after long-term noise exposure - a systematic review. Scand J Work Environ Health (2018). doi:10.5271/sjweh.3725 https://www.ncbi.nlm.nih.gov/pubmed/29542804 (Accessed 6 April 2018) 87 Ibid Kemp.
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because the assessment of cochlear function does not depend on how the inner hair cells transmit signals to the auditory nerve, which is what determines the hearing threshold.
In a review, published in March of 2018, Helleman compared OAEs with audiometry, to see how effectively they could monitor the effects of long-term noise exposure on hearing.88 The review included 13 articles, in which 30- 350 participants were followed long-term. A meta-analysis was not possible because there were significant differences in the designs of the studies. Both PTA and OAE showed shifts in individuals, but a congruent pattern could not be observed. The reviewers concluded that OAE could not reliably detect threshold shifts at individual level.
What is the minimal amount of hearing loss that can be measured?
OAEs are normally very stable with time and are valuable as a sensitive monitor of changes in cochlear and middle ear status over time. Though they can differ enormously between healthy ears in different people, they are usually quite stable in left and right ears in the same person.
It has been suggested that OAEs are more sensitive than pure tone audiometry in detecting the early stages of permanent noise-induced inner ear damage in humans. In a study of 285 U.S. Marine Corps recruits and 32 controls, the participants were exposed to three weeks of weapons’ fire, and their hearing was measured with PTA and with OAEs before and after exposure. Among the noise-exposed volunteers, there were significant decreases in OAE amplitude, but no change in audiometric thresholds.89
The group average decrement in hearing was 0.84 dB. Both DPOAEs and TEOAEs showed significant decreases in OAE levels after the noise exposure. The criteria for significant emission shifts were a shift of 4 to 6 dB for TEOAEs, and 6 to 10 dB and 7 to 8 dB for the DPOAEs (for the two different frequencies of applied tones). These were determined by considering the emission shifts in the group that were not exposed to noise, as presumably any such shifts would be due to chance. The researchers hypothesised that these emission shifts could be due to inner-ear damage in the 2-4 kHz range, which causes subclinical changes insufficient to affect audiometric thresholds, but to which OAEs are sensitive. This is consistent with observations in animals that outer hair cells can be damaged without any change in audiometric thresholds, and the idea that OHC loss shows up on OAE testing because OAE measurements directly measure OHC activity. The authors of this study, published in 2008, comment that, ‘The standard clinical protocol, which produces a resolution of 5 dB, may hinder the detection of small changes in audiometric thresholds, even in the group average’.
A slightly older study, in which participants’ hearing was measured before and after 6 months of noise exposure on an aircraft carrier, also found that the average amplitude of the OAE decreased significantly and the average audiometric thresholds did not change.90
Different sources report different hearing thresholds above which OAEs will not be present. Reported thresholds are: • Kemp:91 20 dB. • Kung and Wilcox 2007:92 25 to 30 dB. • Musiek and Chermak: 30 dB for transient OAEs and approximately 40 dB for DPOAEs. • Cunningham:93 If DPOAE is present with 70 dB stimulus, this can only tell us that the listener has no greater than moderate hearing loss. If DPOAE is present with 65 and 55 dB, we can assume normal OHC function and, indirectly, normal hearing.
88 Ibid Helleman. 89 Marshall, L. et al. Detecting incipient inner-ear damage from impulse noise with otoacoustic emissions. The Journal of the Acoustical Society of America 125, 995–1013 (2009). https://pdfs.semanticscholar.org/b7e9/ae6d3bcb84aa5b9297da10bf64f30ebfe515.pdf (Accessed 3 April 2018) 90 Lapsley Miller, J. A., Marshall, L., Heller, L. M. & Hughes, L. M. Low-level otoacoustic emissions may predict susceptibility to noise-induced hearing loss. The Journal of the Acoustical Society of America 120, 280–296 (2006). https://www.researchgate.net/profile/Laurie_Heller/publication/6911749_Low- level_otoacoustic_emissions_may_predict_susceptibility_to_noise- induced_hearing_loss/links/02e7e524c3f573679d000000.pdf (Accessed 6 April 2018) 91 Ibid Kemp. 92 Kung, B. C. & Willcox Jr., T. O. CHAPTER 25 - EXAMINATION OF HEARING AND BALANCE. in Neurology and Clinical Neuroscience (eds. Schapira, A. H. V. et al.) 318–327 (Mosby, 2007). doi:10.1016/B978-0-323-03354-1.50029- 8 https://www.sciencedirect.com/topics/medicine-and-dentistry/otoacoustic-emission (Accessed 6 April 2018) 93 Ibid Cunningham.
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• Gorga:94 DPOAE could best distinguish between normal and impaired ears when normal hearing was defined as audiometric thresholds between 20 and 30 dB.
Models have been created that attempt to estimate the hearing thresholds from DPOAE data. For example, Boege and Janssen (2002) found that DPOAE enabled a reliable estimation of cochlear hearing threshold up to hearing losses of 50 dBHL.95
The ‘Gorgagram’ is a method used to assign any measured DPOAE value with the probability that the response is coming either from the distribution of normal or impaired responses (from Gorga in Ear and Hearing). The graph shows how DPOAE values correlate with normal hearing and hearing-impaired patients at different frequencies. The top line represents the DPOAE levels expected from the 90th percentile of hearing-impaired patients, i.e. the levels that would be expected in someone who has hearing impairment, but has better hearing than 90% with hearing impairment. The bottom line represents the 5th percentile of normal hearing patients, i.e. the DPOAE levels expected for someone who has normal hearing, but whose hearing is worse than 95% of normal hearing people. The shaded region is the borderline region. Anyone whose DPOAE level is above the shaded region has, most likely, impaired hearing at that frequency, and anyone whose DPOAE level is below the shaded region has, most likely, normal hearing at that frequency.
Figure: The ‘Gorgagram:96
A study by Wooles aimed to examine whether distortion product optoacoustic emissions can serve as a replacement for pure tone audiometry in longitudinal screening of workers exposed to noise. No clinically relevant relationship between DPOAE amplitude and PTA threshold, at matched frequencies, was apparent.97
Summary
Several studies have found that OAEs are not a suitable tool for prediction of PTA thresholds, and other studies have found that noise can affect OAEs but not PTA thresholds.
OAEs are not detectableif the hearing threshold is above a particular level, the value of which ranges from 20 to 40 dB in different studies. If there is no detectable OAE above, for example 30 dB, then the hearing threshold could be any value above 30 dB. This means that an increase in threshold from, for example, 45 dB to 55 dB, would not be detected. Put another way, the size of hearing loss could only be detected if the before and after thresholds were both less than the particular value. If the initial threshold was found to be below 30 dB, and then there was
94 Gorga, M. P. et al. From Laboratory to Clinic: A Large Scale Study of Distortion Product Otoacoustic Emissions in Ears with Normal Hearing and Ears with Hearing Loss. Ear and Hearing 18, 440 (1997). 95 Boege, P. & Janssen, T. Pure-tone threshold estimation from extrapolated distortion product otoacoustic emission I/O-functions in normal and cochlear hearing loss ears. The Journal of the Acoustical Society of America 111, 1810–1818 (2002). https://asa.scitation.org/doi/abs/10.1121/1.1460923 (Accessed 3 April 2018) 96 Figure from https://www.audiologyonline.com/articles/otoacoustic-emissions-beyond-newborn-hearing-838 97 Wooles, N., Mulheran, M., Bray, P., Brewster, M. & Banerjee, A. R. Comparison of distortion product otoacoustic emissions and pure tone audiometry in occupational screening for auditory deficit due to noise exposure. J Laryngol Otol 129, 1174–1181 (2015). https://www.ncbi.nlm.nih.gov/pubmed/26549131 (Accessed 6 April 2018)
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no reading recorded in a later test, this shows that hearing loss has occurred, but the size of the loss cannot be determined.
The study of the military workers found that changes in emission level of 6 to 10 dB were detectable. However, the exact relationship between emission level and hearing threshold is unclear, as some studies report that emission levels correlate well with hearing thresholds, but Kemp, who discovered OAEs, makes the point that the presence or lack of an OAE response is significant, but the size of the response is not.
2. SPEECH INTELLIGIBILITY TESTING
Speech intelligibility is a measure of how much speech can be understood by a listener. Hearing loss patients may often be able to hear clearly in quiet conditions, but have difficulty understanding speech when there is background noise. Various attempts have been made over the years to assess the handicap of these listeners.
The articulation index (AI) is, in general, an expression of the proportion of the average speech signal that is audible to a given patient, and takes values in the range from 0 to 1.0. The concept of the articulation index was introduced in the 1940s.98
A simple and comprehensible procedure for calculating the AI was developed by Pavlovic, in the late 1980s.99 His method uses the pure tone audiogram and involves adding the number of ‘audible decibels’ at 500, 1000, 2000 and 4000 Hz, and then dividing by 120, which is the total number of decibels. In 1990, Mueller and Killion published an easier to use version of this, known as the count-the-dot method.100
Count-The-Dot Method
The count-the-dot method is a method by which the articulation index (AI) may be estimated. The AI is usually calculated by considering the speech signals in several frequency bands, which are weighted by their relative importance, or the amount of speech information contained. The frequency region surrounding 2 kHz is generally considered to contain the most speech information. The count-the-dot method involves tracing the patient’s pure tone audiogram onto the following diagram and counting the dots that are below the line – these are the parts of the speech spectrum that are audible to the listener. There are 100 dots in total, and if 70 dots were audible, the listener would have an AI of 0.7. However, this does not mean that the listener has 70% speech intelligibility – the relationship between the AI and the percentage of various types of speech that would be intelligible is shown in the second figure (below). An AI of 0.7 would correspond to between 95 and 100 % of sentences and 85-90 % of single syllable words being audible. An AI of 0.7 would also correspond to a normal-hearing listener listening to a speech level that is about 9 dB louder than the background noise (see diagram below).
Figure: Count-the-dot audiogram by Mueller and Killion
98 French, N. R. & Steinberg, J. C. Factors Governing the Intelligibility of Speech Sounds. The Journal of the Acoustical Society of America 19, 90–119 (1947). https://asa.scitation.org/doi/abs/10.1121/1.1916407 (Accessed 16 April 2018) 99 Pavlovic, C. V. Articulation index predictions of speech intelligibility in hearing aid selection. ASHA 30, 63–65 (1988). 100 An Easy Method For Calculating the Articulation Index. Mueller, G. and Killion, M.C. http://www.etymotic.com/media/publications/erl-0020-1990.pdf (Accessed 16 April 2018)
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Figure Articulation Index (AI):
Mueller and Killion note that caution must be taken when using the above chart to predict a patient’s performance. The clinically measured audibility is often not the level of audibility for real-life listening situations. For many communication settings, the masking effect of background noise will lower the hearing threshold and the resulting AI can be much lower. Also, perceptual aberrations other than threshold sensitivity loss, might exist and affect speech intelligibility. This is not likely to be an accurate measure of a listener’s ability.
The dots diagram was updated in 2010 to reflect new reports suggesting that higher frequencies contribute more information to speech understanding that was originally thought. The new dots diagram is shown below101:
Figure: 2010 Count-the-dots diagram
In the 2010 article, the authors emphasise that the theoretical relationship between AI and intelligibility applies only to normal-hearing individuals.
101 Killion, M. C. & Mueller, H. G. Twenty years later: A new Count-the-dots method. The Hearing Journal 63, (2010). http://thehearingblog.com/wp-content/uploads/Count-The-Dots-by-Mead-Killion.pdf (Accessed 16 April 2018)
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Speech Intelligibility Index
The AI was updated and succeeded by the speech intelligibility index. The speech intelligibility index (SII) was introduced in the late 1990s, and, like the AI, is a quantification of the proportion of speech information that is both audible and usable for a listener. The SII can take values between 0.0 and 1.0, and as it increases, speech understanding generally increases. The SII and speech understanding are similar, but not exactly the same. For example, an SII of 0.7 does not mean that the listener would understand 70% of the speech. The SII and the AI can be used to predict speech recognition scores. This was shown above, in the AI section. The primary difference between the SII and the AI is that the information required for the SII calculation is more flexible. SII is calculated, over a number of different frequencies, by comparing the level of the speech peaks (possible sounds in speech) with the auditory thresholds or the level of background noise. It is assumed that elevated thresholds and background noise function, in the same way, limit audibility. The scope of the SII is limited to listeners without hearing loss.102
Rather than being a direct measure of hearing loss, the SII is a measure of the impact of hearing loss on the understanding of speech. The count-the-dots method is a diagnostic test rather than a hearing test.
3. SPEECH IN NOISE TESTING
QuickSIN
The QuickSIN is a speech-in-noise listening test that measures listeners’ ability to hear in noise. The designers of the QuickSIN say that speech understanding in noise cannot be reliably predicted from the pure tone audiogram or other standard audiometric tests.103 In the test, a list of six sentences, with 5 key words per sentence, is presented in four-talker babble noise. The sentences are presented at different signal-to-noise ratios (the difference in loudness between the interesting speech and the background noise), which decrease in 5 dB steps. The test was developed to provide a quick way for clinicians to quantify a patient’s ability to hear in noise, and to aid with selecting hearing aids. The test gives a signal to noise ratio loss, which is calculated by subtracting the number of correctly identified words from 25.5. The figure below shows 6 sentences presented at different speech to noise ratios, the listener’s score for each sentence, and their SNR loss result of 3.5. As there are 5 words at each 5 dB interval, each word can be thought of as being equivalent to one dB. It is not stated in the QuickSin Guide, but presumably the numbers in the right-hand column are the numbers of words that a normal-hearing listener would be expected to correctly identify.
The SNR loss score is then classified, as shown in the table below:
102 Hornsby, B. W. Y. The Speech Intelligibility Index: What is it and what’s it good for? The Hearing Journal 57, 10 (2004). https://journals.lww.com/thehearingjournal/Fulltext/2004/10000/The_Speech_Intelligibility_Index__What_is_it_and.3.aspx (A ccessed 24 April 2018) 103 QuickSIN TM Speech-in-Noise Test. Etymotic. https://www.etymotic.com/auditory-research/speech-in-noise- tests/quicksin.html (Accessed 24 April 2018)
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In summary, the QuickSIN test measures the loss in speech to noise ratio. In other words, the test shows the increase in signal-to-noise ratio needed by a listener compared to the average listener with normal hearing.
It has been reported that 12 equivalent sentence lists comprise the QuickSIN test that measures the speech to noise ratio that a listener requires in order to understand 50% of key words in background noise. The standard deviation of scores from a single list is 1.4 dB for hearing-impaired subjects, based on test-retest data. A single QuickSIN list takes approximately one minute to administer and provides an estimate of SNR loss accurate to +/- 2.7 dB in 95% of listeners.104
A 2006 study investigated the equivalency of the 18 possible QuickSIN test lists. There was high performance variability across lists for listeners with hearing loss but not for listeners with normal hearing. Nine of the lists provided homogenous results for listeners with and without hearing loss.105
According to a study in which the BKB-SIN, HINT, QuickSIN and WIN tests were compared among normal and hearing-impaired listeners, the QuickSIN and WIN methods were more sensitive measures of recognition of speech in background noise than the BKB-SIN and HINT methods, due to larger differences found between normal hearing and hearing-impaired groups106.
Hearing In Noise Test (HINT)
The Hearing in Noise Test (HINT) is a way of measuring a listener’s ability to hear speech in the quiet and in noise.107 During the test, the listener repeats sentences that they have heard, with either no competing noise, or with competing noise coming from in front, to the left and to the right of the patient. The loudness of the sentences is varied throughout the test, depending on whether the patient repeats it correctly or not. The tester scores each sentence repeated as either correct or incorrect. All words in the sentence must be repeated correctly for it to be recorded as being correct. At the end of the test, a signal-to-noise ratio (SNR) is generated for each test condition. This is a measure of how much louder the sentences need to be than the background noise for the patient to repeat them correctly 50% of the time. For example, a SNR of 5 dB means that the sentences had to be presented at 70 6B (5 dB above the 65 dB background noise) to be repeated correctly 50% of the time.108
The test shows the listener’s signal to noise ratio threshold, the SNR threshold, as a percentile in reference to the normal distribution of other listeners, and the maximum percent change in intelligibility relative to the average normal performance. In other words, the listener can find out how their score compares to other peoples’ scores. The comparison of the BKB-SIN, HINT, QuickSIN and WIN tests found that the HINT test was a less sensitive measure of recognition performance in background noise than the QuickSIN and WIN tests.
Words In Noise (WIN) test
The Words In Noise or WIN test was designed to measure a listener’s ability to understand single syllable words in background noise.109 Initially, there was a list of 70 words to be tested, which was split into 10 words at 7 different signal-to-noise ratios, from 24 to 0 dB, in 4 dB increments. This was later split into two equivalent 35-word lists, and
104 Killion, M. C., Niquette, P. A., Gudmundsen, G. I., Revit, L. J. & Banerjee, S. Development of a quick speech-in-noise test for measuring signal-to-noise ratio loss in normal-hearing and hearing-impaired listeners. J. Acoust. Soc. Am. 116, 2395–2405 (2004). https://www.ncbi.nlm.nih.gov/pubmed/15532670%20?iframe=true&width=100%&height=100% (Accessed 24 April 2018) 105 McArdle, R. A. & Wilson, R. H. Homogeneity of the 18 QuickSINTM Lists. Journal of the American Academy of Audiology 17, 157–167 (2006). https://www.audiology.org/sites/default/files/journal/JAAA_17_03_01.pdf (Accessed 24 April 2018) 106 Wilson, R. H., McArdle, R. A. & Smith, S. L. An Evaluation of the BKB-SIN, HINT, QuickSIN, and WIN Materials on Listeners With Normal Hearing and Listeners With Hearing Loss. J Speech Lang Hear Res 50, 844–856 (2007). https://www.researchgate.net/profile/Sherri_Smith4/publication/6162979_An_evaluation_of_the_BKB- SIN_HINT_QuickSIN_and_WIN_materials_on_listeners_with_normal_hearing_and_listeners_with_hearing_loss/links/545bde1c0cf249 070a7a81b7.pdf (Accessed 25 April 2018) 107 Nilsson, M., Soli, S. D. & Sullivan, J. A. Development of the Hearing In Noise Test for the measurement of speech reception thresholds in quiet and in noise. The Journal of the Acoustical Society of America 95, 1085–1099 (1994). https://asa.scitation.org/doi/abs/10.1121/1.408469 (Accessed 29 April 2018) 108 Hearing in Noise Test (HINT). California Ear Institute. http://www.californiaearinstitute.com/audiology-services-hint-bay-area- ca.php (Accessed 24 April 2018) 109 Wilson, R. H. Development of a speech-in-multitalker-babble paradigm to assess word-recognition performance. J Am Acad Audiol 14, 453–470 (2003).
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a third list was developed as a practice list. It was found that the same group of listeners obtained similar scores on lists 1 and 2.110
A group of older listeners with sensorineural hearing loss took part in a study to assess the differences in responses in one test and between separate tests. Among 315 participants who took two tests 1 year apart, the 50% correct S/N ratios were 12.5 and 12.8 dB. In the second part of the study, two tests were taken 40 days apart, and the 50 % correct S/N ratios were 13.0 and 13.4 dB for 48 participants with mild-to-severe hearing loss, and 15.3 and 15.8 dB for 48 participants with moderate-to-severe hearing loss. There were no significant differences within the tests.111 The authors of the study concluded that the results from both the 70 and 35-word versions of the WIN, indicate that for listeners with various degrees of sensorineural hearing loss, the WIN provides both a stable and reliable measure of word-recognition performance in background noise. Mean differences between listeners with normal hearing and listeners with hearing loss were 6-9 dB.112
According to a study in which the BKB-SIN, HINT, QuickSIN and WIN tests were compared among normal and hearing impaired listeners, the Quick Sin and WIN methods were more sensitive measures of recognition of speech in background noise than the BKB-SIN and HINT methods, due to the larger differences found between normal hearing and hearing-impaired groups.113
BKB-SIN
This is another speech in noise test that uses Bamford-Kowal-Bench sentences, recorded with 4-talker background noise. The test contains 18 'List Pairs' of sentences. The first sentence in each list has four key words, and the remaining sentences each have three. The numbers of correct words for each list are added, and the total is subtracted from 23.5 to obtain the signal-to-noise ratio at which 50% of words are correct (SNR-50). The scores are then classed as normal/near normal, mild SNR loss, moderate SNR loss and severe SNR loss, according to the table shown in the discussion on QuickSIN, above.114 This test is very similar to the QuickSIN test – the only differences are the sentences used, and that the QuickSIN has a female speaker, whereas the BKB-SIN has a male speaker.
Summary
Measurement of the speech intelligibility index is intended to be performed on normal hearing listeners, making it an unhelpful tool for determining the amount of hearing loss.
The hearing-in-noise tests determine how much louder speech needs to be in order to be understood by the listener, in the presence of background noise. In the QuickSIN test, each word heard correctly corresponds to 1 dB of SNR, so the SNR can be measured to the nearest 1 dB. It has been reported that the QuickSIN test is accurate to +/- 2.7 dB SNR in 95% of listeners.
According to a study, in which the BKB-SIN, HINT, QuickSIN and WIN tests were compared among normal and hearing-impaired listeners, the Quick Sin and WIN methods were more sensitive measures of recognition of speech in background noise than the BKB-SIN and HINT methods, due to larger differences between normal hearing and hearing-impaired groups.
110 Wilson, R. H. & Watts, K. L. The Words-in-Noise Test (WIN), list 3: a practice list. J Am Acad Audiol 23, 92–96 (2012). https://www.ncbi.nlm.nih.gov/pubmed/22353677 (Accessed 29 April 2018) 111 Wilson, R. H. & McArdle, R. Intra- and inter-session test, retest reliability of the Words-in-Noise (WIN) test. J Am Acad Audiol 18, 813–825 (2007). https://pdfs.semanticscholar.org/a89e/9b74dabde2ff55a01b9320e92b9ea493e09b.pdf (Accessed 29 April 2018) 112 Ibid Wilson (2003). 113 Wilson, R. H., McArdle, R. A. & Smith, S. L. An Evaluation of the BKB-SIN, HINT, QuickSIN, and WIN Materials on Listeners With Normal Hearing and Listeners With Hearing Loss. J Speech Lang Hear Res 50, 844–856 (2007). https://www.researchgate.net/profile/Sherri_Smith4/publication/6162979_An_evaluation_of_the_BKB- SIN_HINT_QuickSIN_and_WIN_materials_on_listeners_with_normal_hearing_and_listeners_with_hearing_loss/links/545bde1c0cf249 070a7a81b7.pdf (Accessed 25 April 2018) 114 https://www.etymotic.com/downloads/dl/file/id/260/product/160/bkb_sintm_user_manual.pdf (Accessed 29 April 2018)
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Feature: Hearing Testing Methods Additional to Pure Tone Audiometry (Part 2) (BCDN Edition 236)
In last week’s feature (here), we considered the use of oto-acoustic emissions, speech intelligibility testing and speech in noise testing as alternatives to pure tone audiometry (PTA) testing.
As previously discussed, in this week’s feature, we review the use of 3 further methods capable of diagnosing hearing loss: 1. Cortical Electric Response Audiometry (CERA) 2. Auditory Brainstem Response (ABR) 3. Auditory Steady State Response
(ASSR)CORTICAL ELECTRIC RESPONSE AUDIOMETRY (CERA)
CERA is a hearing test that records signals from the auditory cortex (the part of the brain that recognizes sound) when sound is detected. CERA testing is an evaluation of the function of the whole auditory pathway, which signals pass through. The auditory pathway starts with detection, in the cochlea, and ends with processing, in the auditory cortex. The auditory pathway is shown in the figure below:
Figure: The auditory pathway115
During testing, noises are sent to earphones that a patient wears. Electrodes are attached to the patient’s head. These track the brain’s response to sound (clicking noises) and record the responses. The response to noises of different frequencies can be measured. An advantage of this technique over pure tone audiometry (PTA) is that, like oto-acoustic emissions (OAE) testing, which was discussed in last week’s feature, the test is objective. The patient does not have to ‘decide’ whether or not they have heard the tone. The threshold is defined as the lowest level at which a response is present.
CERA is useful when PTA results are in doubt, or are clearly erroneous. The measured response does not fully mature until a patient reaches late teenage years, and thus, CERA is widely regarded as a test for adults[i]. Most of the literature on CERA is from the 1960s and 1970s, before the Auditory Brainstem Response (ABR) test became the more popular field of research.
115 Figure from https://www.slideshare.net/Daritsetseg/brainstem-auditory-evoked-responses-baer-or-abr-45762118 (Accessed 5 May 2018)
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How Reliable Is It?
Studies that report on the accuracy of CERA testing compare PTA thresholds with CERA thresholds.
Research shows that if testing parameters and protocol are chosen with care, the response is capable of being within 10 dB of the PTA response in almost all patients116.
A 2002 study, by Tsui, found that 83.2% of patients had PTA and CERA thresholds within 10 dB. The mean difference in values, in 408 ears tested, was less than 5 dB at 1, 2 and 3 kHz.117
Some academics have reported that the accuracy of CERA testing is poor. However, inappropriate parameters and methodology may be responsible for this.118 A 1991 study, by Albera, found that the mean difference between CERA and PTA thresholds ranged between 6 and 13 dB.119 A study by Lightfoot and Kennedy found that the mean error in the CERA threshold (the difference from the PTA threshold) was 6.5 dB, with no significant effect of frequency. 94% of individual thresholds were within 15 dB of the PTA thresholds and 80% were within 10 dB.120
In a 1993 study, Prasher and colleagues compared CERA and pure tone thresholds among a group of patients seeking medicolegal compensation for noise induced hearing loss and another group with Ménière's disease.121 The cortical and PTA thresholds were ‘within 10 dB’ for 84% of the NIHL cases and 92% of the Ménière's cases. In the remaining 16% of NIHL cases, 13% exaggerated the PTA thresholds at 1 kHz and 10% at 4 kHz. Another study of compensation claimants found that CERA thresholds were within 10 dB of ‘true thresholds’ in almost all patients.122
Moreover, in the introduction of a study, which compared CERA thresholds with auditory steady state response (ASSR) thresholds (see 3rd section of this feature), the authors present the maximum discrepancies between CERA and PTA thresholds at multiple frequencies:123 • 500 Hz: 15 dB • 1 kHz: 10 dB • 2 kHz: 10 dB • 4 kHz: 10 dB
A British Society of Audiology Recommended Procedure document, published in September 2015, discusses threshold and accuracy and limitations of the technique124. If a step size of 10 dB has been used (i.e. the generated sounds differ in intensity by 10 dB) the tester may report the threshold by interpolation. The threshold may be reported as 5 dB below the lowest level at which a response is seen, providing that the response is larger than a
116 Background information on Cortical ERA. http://corticalera.com/basics.html (Accessed 10 April 2018) 117 Hyde, M., Matsumoto, N., Alberti, P. & Li, Y.-L. Auditory Evoked Potentials in Audiometric Assessment of Compensation and Medicolegal Patients. A n n O t ol R hin ol L a r y n g ol 95, 514–519 (1986). http://journals.sagepub.com/doi/abs/10.1177/000348948609500514 (Accessed 10 April 2018) 118 Tsui, B., Wong, L. L. N. & Wong, E. C. M. Accuracy of cortical evoked response audiometry in the identification of non-organic hearing loss: Exactitud de la audiometría por respuestas corticales evocadas en la identificación de hipoacusia no orgánica. In t e r n a tio n al J o u r n al o f A u diolo g y 41, 330–333 (2002). https://s3.amazonaws.com/academia.edu.documents/42824107/Accuracy_of_cortical_evoked_response_aud20160218- 2511585jqr7.pdf?AWSAccessKeyId=AKIAIWOWYYGZ2Y53UL3A&Expires=1523320172&Signature=Vcn3jIgXuZ1VkHjuzx171dgap8o %3D&resp onse-content-disposition=inline%3B%20filename%3DAccuracy_of_cortical_evoked_response_aud.pdf (Accessed 10 April 2018) 119 Background information on Cortical ERA. http://corticalera.com/basics.html (Accessed 10 April 2018) 120 Albera, R. et al. [Relations between pure-tone audiometry and cortical evoked auditory potentials]. Acta Otorhinolaryngol Ital 11, 551–562 (1991). http://europepmc.org/abstract/med/1819182 (Accessed 10 April 2018) 121Lightfoot, G. & Kennedy, V. Cortical Electric Response Audiometry Hearing Threshold Estimation: Accuracy, Speed, and the Effects of Stimulus Presentation Features. Ear and Hearing 27, 443 (2006). http://corticalera.com/onewebmedia/LightfootKennedyEH2006.pdf (Accessed 10 April 2018) 122Prasher, D., Mula, M. & Luxon, L. Cortical evoked potential criteria in the objective assessment of auditory threshold: a comparison of noise induced hearing loss with Ménière’s disease. T h e J o u r n al o f L a r y n g olo g y & a m p ; O t olo g y 107, 780–786 (1993). https://www.cambridge.org/core/journals/journal-of-laryngology-and-otology/article/cortical-evoked- potential-criteria-in-theobjective-assessment-of-auditory-threshold-a-comparison-of-noise-induced-hearing-loss-with- menieresdisease/2CBD99701BD8680CC77598E7F4C952D5 (Accessed 5 May 2018) 123 Hyde, M., Matsumoto, N., Alberti, P. & Li, Y.-L. Auditory Evoked Potentials in Audiometric Assessment of Compensation and Medicolegal Patients. A n n O t ol R hin ol L a r y n g ol 95, 514–519 (1986). http://journals.sagepub.com/doi/abs/10.1177/000348948609500514 (Accessed 5 May 2018) 124 Yeung, K. N. K. & Wong, L. L. N. Prediction of hearing thresholds: Comparison of cortical evoked response audiometry and auditory steady state response audiometry techniques. In t e r n a tio n al J o u r n al o f A u diolo g y 46, 17–25 (2007). https://hub.hku.hk/bitstream/10722/53617/2/133986.pdf?accept=1 (Accessed 5 May 2018)
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specified amplitude: when the response is smaller than the specified amplitude, the threshold is taken as the lowest response. How does the CERA threshold relate to the true threshold? The document quotes a bias (difference from PTA threshold) of 6.5 dB, which is rounded down to 5 dB. It is explained that a when CERA threshold is obtained, the bias of 5 dB is subtracted, and then the ‘true’ value lies within ±15 dB of this value, because Lightfoot and Kennedy found that 94% of the differences between PTA and CERA were less than or equal to 15 dB. For example, if the CERA threshold was 50 dB, 5 dB is subtracted to get a value of 45 dB, and then there is a 95% chance that the PTA threshold lies in the range 30-60 dB HL (45 ± 15).
Accuracy can be influenced by other factors, such as drowsiness. Ideal conditions would involve generally alert patients. It is also ideal for patients to read a magazine during testing. In a small percentage of individuals, the error in thresholds exceeds 30 dB, for no apparent reason125. The Tsui study reported that there were occasionally discrepancies between PTAs and CERAs of (–)50 dB to (+)35 dB.
It has been suggested that CERA testing is a useful tool for detecting patients that exaggerate their hearing thresholds in PTA testing.126
What Is The Smallest Hearing Loss Measurable?
Taking the example from the British Society of Audiology, above, if the CERA threshold is 50 dB, this means that there is a 95% chance that the actual threshold is in the range of 30-60 dB HL. Thus, the actual hearing threshold could be 20 dB below the recorded CERA threshold (30 dB is 20 dB less than 50 dB). If the highest threshold considered to be ‘normal’ hearing at a particular frequency is, say, 10 dB, then the recorded CERA threshold would need to be more than 20 dB higher than this to be able to claim that the actual threshold is above 10 dB. This would mean that the CERA threshold would have to be more than 30 dB. Therefore, the smallest difference in threshold that could be considered to be a hearing loss would be 20 dB above the ‘normal’ range. Put another way, if the threshold for normal hearing is 10 dB and the recorded CERA threshold is 20 dB, the listener’s actual hearing threshold could be between 0 and 30 dB, which means that their threshold could be below 10 dB, putting them into the normal hearing range.
Summary
Studies have found that CERA thresholds tend to be within 10-15 dB of PTA threshold values. They tend to report on the accuracy of CERA testing by comparing CERA and PTA results, on the basis that PTA thresholds are considered to be the ‘true’ values.
AUDITORY BRAINSTEM RESPONSE (ABR)
Like CERA testing, ABR testing aims to estimate the listener’s hearing thresholds by detecting signals from the nervous system. The difference between the two techniques is that signals are generated by different parts of the auditory nervous system. In ABR testing, the signals are detected by the brain stem, whereas in CERA testing, the signals are detected by the auditory cortex. ABR assesses the function of the inner ear up to the auditory brainstem, whereas CERA testing measures hearing along the entire auditory pathway. The auditory pathway diagram is repeated below:
125 Recommended Procedure. Cortical Auditory Evoked Potential (CAEP testing). British Society of Audiology. http://www.thebsa.org.uk/wp-content/uploads/2016/01/BSA-Cortical-ERA-Guidance-for-consultation.pdf (Accessed 14 April 2018) 45 Albera, R. et al. [Relations between pure-tone audiometry and cortical evoked auditory potentials]. Acta Otorhinolaryngol Ital 11, 551–562 (1991). http://europepmc.org/abstract/med/1819182 (Accessed 10 April 2018) 126Stephen, W. H., Garry, N., Ivan, K. & Vivian, K. The Use of Cortical Evoked Response Audiometry in the Assessment of Noise- Induced Hearing Loss. O t ola r y n g ol H e a d N e c k S u r g 128, 257–262 (2003). http://journals.sagepub.com/doi/abs/10.1067/mhn.2003.79 (Accessed 10 April 2018)
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Figure: The auditory pathway127
The structures that produce the signals, which are then detected by ABR, are believed to be the cochlear nerve, cochlear nucleus, superior olivary complex and the lateral lemnscus (stages 2 to 5 of the auditory pathway).
In general, ABR responses tend to be less variable, more robust and less affected by the patient’s mental state than CERA responses. However, low levels of muscle activity are required for accurate ABR readings; the patient is required to be very relaxed. CERA test results are much less sensitive to muscle activity, but as discussed above, are affected by mental alertness levels. Is it difficult to test low frequencies using ABR, because stimuli sounds have to be of short duration.
ABR testing often uses clicks and pips (short bursts of sound at a particular frequency), but in the last 20 years, has also used more complex signals, such as syllables from various languages, syllables with background noise, musical tones and chords.
The differences between ABR and CERA testing are conveyed in the table below:
Figure: Advantages and disadvantages of ABR and CERA testing128
127 Figure from https://www.slideshare.net/Daritsetseg/brainstem-auditory-evoked-responses-baer-or-abr-45762118 (Accessed 5 May 2018) 128 Figure from http://corticalera.com/cera-v-abr.html (Accessed 4 May 2018)
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How Accurate Is It?
A 2011 study showed that the results from different tests of ABR, in response to complex sounds, were stable and replicable from session to session. In other words, test-retest variability was low among the ABR data recorded.129 There have been many studies which have investigated the ability of tone-evoked ABR for estimating PTA thresholds, in individuals with normal hearing and individuals with hearing loss. Reviews and meta-analyses have reported that the ABR appears to be 10-20 dB less sensitive than PTA thresholds in adults with normal hearing, with errors in the range of 0.5 to 0.9 dB. Interestingly, in individuals with sensorineural hearing loss, the ABR thresholds are usually 5- 15 dB higher than the PTA thresholds, with an error of around ± 3 dB at each frequency.130 These threshold results are fairly consistent across studies. It appears that the relationship between ABR and PTA thresholds changes after onset of sensorineural hearing loss, such that PTA thresholds and ABR thresholds are slightly closer in listeners with some sensorineural hearing loss. These findings occur within the range of 500 Hz to 4 kHz. In general, PTA thresholds should be able to be predicted from ABR thresholds.131
Other reviews have reported on the ABR technique and the parameters that clinicians should use to provide the most accurate thresholds.132
What Is The Smallest Hearing Loss That Can Be Measured?
A review, by Stapells, reported that, among participants with normal hearing, the mean ABR thresholds ranged between 11.8 and 20.4 dB nHL for 500, 1000, 2000 and 4000 Hz tones.133 The units of dB nHL are on a scale where 0 dB nHL is the average pure tone threshold for adults with normal hearing, at a particular frequency. Overall, the ABR threshold results are consistent across studies, with 95% confidence intervals no larger than ± 5 dB.
A 95% confidence interval roughly corresponds to a situation where, in 95% of individuals, the true threshold will be within 5 dB of the measured threshold. This means that, for example, a difference of up to 10 dB between two thresholds, recorded at different points in time, is not indicative of hearing loss (because one measurement could be up to 5 dB less and the other up to 5 dB more than the ‘true’ threshold), but a difference of more than 10 dB does suggest that the two readings show different thresholds.
If a single threshold value is being compared against a range of normal hearing, the value can be considered as falling outside outside the normal range if it is more than 5 dB higher than the highest value of the normal range. In other words, if the normal hearing ABR threshold range is 11.8 to 20.4 dB nHL, a threshold of more than 25.4 nHL could be considered to be a hearing loss. As this is 5 dB above the top of the normal range, the smallest hearing loss that can be measured can be thought of as being 5 dB.
Summary
Most studies of ABR testing compare ABR thresholds with pure tone audiometry thresholds. It appears that the ABR thresholds are closer to pure tone thresholds in listeners with sensorineural hearing loss. ABR thresholds tend to be higher than pure tone thresholds. Overall, ABR thresholds errors tend to be within 5 dB of the ‘true’ threshold. A study of test-retest variability has found little variation between ABR thresholds when the same participants were tested more than once.
129 Song, J. H., Nicol, T. & Kraus, N. Test-Retest Reliability of the Speech-Evoked Auditory Brainstem Response in Young Adults. Clin Neurophysiol 122, 346–355 (2011). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2990784/ (Accessed 5 May 2018) 130 Stapells DR. Threshold estimation by the tone-evoked auditory brainstem response: a literature meta-analysis. Journal of Speech Language Pathology and Audiology. 2000;24(2):74-83. https://www.researchgate.net/publication/268802004_Threshold_estimation_by_the_toneevoked_auditory_brainstem_response_ A_literature_meta-analysis (Accessed 5 May 2018) 131 Gorga MP, Neely ST. Some factors that may influence the accuracy of auditory brainstem response estimates of hearing loss. A Sound Foundation Through Early Amplification. 2001:49-61. https://pdfs.semanticscholar.org/d7f4/fdd0864dcd3482e6b8d7dccb3455143fa9e7.pdf (Accessed 5 May 2018) 132 Stapells, D. R. & Oates, P. Estimation of the Pure-Tone Audiogram by the Auditory Brainstem Response: A Review. AUD 2, 257– 280 (1997). https://www.researchgate.net/profile/David_Stapells/publication/13838912_Estimation_of_the_PureTone_Audiogram_by_the_Audi tory_Brainstem_Response_A_Review/links/54ae9f480cf2b48e8ed452c2/Estimation-of-the-Pure-ToneAudiogram-by-the-Auditory- Brainstem-Response-A-Review.pdf 133 Ibid Stapells 2000
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AUDITORY STEADY STATE RESPONSE (ASSR)
ASSR is another technique that uses electrical measurements to estimate pure tone thresholds. Like ABR, ASSR measures signals generated by the auditory system. The main difference between the techniques is the nature of recorded signals. ASSR signals are evoked using repeated sound stimuli, presented at a high repetition rate, whereas ABR is evoked using brief sounds presented at a relatively low repetition rate. In ABR testing, the examiner has to interpret the data and decide whether a response is present. This becomes increasingly difficult as the ABR approaches the true threshold, when the result is the most important. Conversely, ASSR uses an objective, sophisticated, statistics-based, mathematical detection algorithm to detect and define hearing thresholds.134 Furthermore, ABR is typically measured one ear at a time, whereas ASSR can measure both ears at the same time.
Currently, there is no universal standard for ASSR instrumentation. Stimulus and recording parameters and methods are designed (and may vary) by each manufacturer.
ASSR was developed later than CERA and ABR. As a result, studies on ASSR have been conducted more recently. However, many recent studies of ASSR are in children. Some studies of ASSR in children have reported that those with functional hearing loss tend to produce ASSR and PTA thresholds that are significantly different and weakly correlated.135
How Accurate Is It?
A 1995 study, by Rance and colleagues, found that, among hearing impaired subjects, the difference between pure tone thresholds and ASSR thresholds decreased with increasing hearing loss. The strength of the relationship also increased with increasing frequency (i.e. the threshold estimates were more accurate in patients with more significant hearing loss and at higher frequencies).136 The researchers made linear graphs of the relationship between the ASSR thresholds and the pure tone thresholds, and produced simple equations that could be used to predict the pure tone thresholds from the ASSR threshold. 94% of the data points were within 10 dB of the regression line on the graphs, meaning that the true value is within 10 dB of the predicted value most of the time.
A 2003 study of patients with NIHL and a characteristic notch between 3 kHz and 6 kHz, found strong correlations between pure tone thresholds and ASSR thresholds, and the correlations became stronger as frequency increased. Typically, the ASSR thresholds overestimated the pure tone thresholds by 10-20 dB, but the shape of the audiogram was closely reflected. In other words, the ASSR audiogram looked very similar to the pure tone audiogram, but the thresholds were shifted up by 10-20 dB. The strength of the correlation was stronger in patients with greater hearing loss.137
A study, by Herdman and Stapells and published in 2002, reported that, among participants with sensorineural hearing loss, the ASSR thresholds were higher, on average, than the pure tone thresholds by: • 14 ±13 dB at 500 Hz. • 8 ± 9 dB at 1 kHz. • 10 ± 10 dB at 2 kHz. • 3 ± 10 dB at 4 kHz.
134Auditory Steady-State Response (ASSR): A Beginner’s Guide. 3 November 2007. http://www.hearingreview.com/2007/11/auditorysteady-state-response-assr-a-beginners-guide/ (Accessed 6 May 2018) 135 Kariya, S., Fukushima, K., Kawasaki, A., Kataoka, Y. & Nishizaki, K. Auditory steady-state responses to multiple simultaneous stimuli in children with functional or sensorineural hearing loss. E u r A r c h O t o r h inolaryngol 265, 769–773 (2008). https://link.springer.com/article/10.1007/s00405-007-0550-3 (Accessed 7 May 2018) 136 Rance, G., Rickards, F. W., Cohen, L. T., De Vidi, S. & Clark, G. M. The automated prediction of hearing thresholds in sleeping subjects using auditory steady-state evoked potentials. (1995). https://minervaaccess.unimelb.edu.au/bitstream/handle/11343/27453/119435_vol8_788.pdf?sequence=1&isAllowed=y (Accessed 5 May 2018) 137 Hsu, W.-C., Wu, H.-P. & Liu, T.-C. Objective assessment of auditory thresholds in noise-induced hearing loss using steady-state evoked potentials. Clinical Otolaryngology & Allied Sciences 28, 195–198 (2003). https://onlinelibrary.wiley.com/doi/full/10.1046/j.13652273.2003.00684.x (Accessed 6 May 2018)
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These results show that the difference between the pure tone thresholds and the ASSR thresholds decreases at higher frequencies. Even though the ASSR overestimated the hearing thresholds, the ASSR audiograms had the same shape as the pure tone audiograms.138
A number of studies have compared ASSR thresholds and pure tone thresholds in infants and children, but these studies are not included, as children and infants should be considered separate from adults with NIHL.
What is more, studies have compared ASSR response with ABR or CERA response.
A study, published in 2002, found that both the ABR and ASSR threshold estimates for the pure tone thresholds in adults varied with frequency, stimulus rate, and detection method.139 Johnson and Brown compared ABR thresholds using two different methods with ASSR thresholds and pure tone thresholds. There was no difference in accuracy between the two ABR techniques or between the two ASSR techniques. Overall, ABR thresholds were 3 dB closer to the pure tone thresholds than the ASSR thresholds. However, in subjects with the most steeply sloping hearing losses, ABR thresholds were recorded as much as 25 dB below the pure tone thresholds, whereas ASSR thresholds were never more than 5 dB below the pure tone thresholds. ASSR overestimated the pure tone thresholds in two of 14 adults with normal hearing, where the ABR was more accurate.
In summary, the researchers concluded that the ABR thresholds were generally more accurate and that ABR may be a more appropriate method in assessing those expected to have slight hearing loss, whereas ASSR may be more appropriate for those with steeply sloping hearing losses.140
In addition, a 2007 study reported that the pure tone thresholds were closer to the CERA thresholds than the ASSR thresholds.141 Both the ASSR and CERA thresholds were closer to the pure tone thresholds at higher frequencies than at lower frequencies. The researchers note that, even though CERA predicts pure tone thresholds slightly more accurately than ASSR, the differences may not be clinically significant, particularly when the degree of individual variations in considered. The predictions of thresholds were more accurate in patients with greater hearing loss.
Overall, these studies found that ASSR thresholds tend to be higher than pure tone thresholds, by 10-20 dB, and that a small number of individual differences are much greater. Both CERA and ABR seem to be slightly more accurate than ASSR.
However, a study published in April of 2018, in which ‘next-generation’ ASSR techniques were used, reported very different results. The researchers tested the hypothesis that advancements in ASSR techniques would result in lower thresholds, and less difference between ASSR and ABR results than in previous studies. The ASSR thresholds recorded were significantly lower than the ABR thresholds recorded. Average differences between ASSR and ABR thresholds were 14.39 dB at 500 Hz, 10.12 dB at 1 kHz, 3.73 dB at 2 kHz and 3.67 dB at 4 kHz. In conclusion, the ASSR thresholds were lower than the ABR thresholds, by up to 14 dB, which juxtaposes the results from previous studies, where ASSR was shown to overestimate hearing thresholds to a greater extent than ABR. The 2018 study was performed on infants and toddlers and did not involve comparison with the pure tone thresholds.142
138 Herdman, A. T. & Stapells, D. R. Auditory steady-state response thresholds of adults with sensorineural hearing impairments: Umbrales de las respuestas auditivas de estado estable en adultos con hipoacusia sensorineural. International Journal of Audiology 42, 237– 248 (2003). https://www.researchgate.net/profile/David_Stapells/publication/10614666_Auditory_steadystate_response_thresholds_of_adults_ with_sensorineural_hearing_impairments/links/5475e7420cf29afed612bed7/Auditory-steadystate-response-thresholds-of-adults- with-sensorineural-hearing-impairments.pdf (Accessed 6 May 2018) 139 Cone-Wesson, B., Dowell, R. C., Tomlin, D., Rance, G. & Ming, W. J. The auditory steady-state response: comparisons with the auditory brainstem response. J A m A c a d A u diol 13, 173–187; quiz 225-226 (2002). https://pdfs.semanticscholar.org/5b2e/5873069c7131a78519dcdaa50b54fd6fd45a.pdf Accessed 5 May 2018) 140 Johnson, T. A. & Brown, C. J. Threshold Prediction Using the Auditory Steady-State Response and the Tone Burst Auditory Brain Stem Response: A Within-Subject Comparison. E a r a n d H e a rin g 26, 559 (2005). https://journals.lww.com/earhearing/Abstract/2005/12000/Threshold_Prediction_Using_the_Auditory.4.aspx (Accessed 6 May 2018) 141 Yeung, K. N. K. & Wong, L. L. N. Prediction of hearing thresholds: Comparison of cortical evoked response audiometry and auditory steady state response audiometry techniques. In t e r n a tio n al J o u r n al o f A u diolo g y 46, 17–25 (2007). https://hub.hku.hk/bitstream/10722/53617/2/133986.pdf?accept=1 (Accessed 5 May 2018) 142 Sininger, Y. S., Hunter, L. L., Hayes, D., Roush, P. A. & Uhler, K. M. Evaluation of Speed and Accuracy of Next-Generation Auditory Steady State Response and Auditory Brainstem Response Audiometry in Children With Normal Hearing and Hearing Loss. Ear and Hearing Publish Ahead of Print, (2018). https://journals.lww.com/earhearing/Abstract/publishahead/Evaluation_of_Speed_and_Accuracy_of.98953.aspx (Accessed 6 May 2018)
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Although ASSR thresholds tend to be further from pure tone thresholds than ABR and CERA thresholds, this does not necessarily mean that ASSR is a worse tool for predicting pure tone thresholds, so long as a reliable calibration method is used. Despite the fact that ASSR thresholds tend to be 10-20 dB more than the PTA thresholds, if once 10- 20 dB (exact figure determined for each frequency from the graphs in the 1995 Rance paper, for example) has been is subtracted from the ASSR threshold, there is a small range within which the PTA threshold could lie, then the ASSR could predict PTA thresholds quite accurately.
What Is The Smallest Hearing Loss That Can Be Measured?
Several studies report that once the average difference between the ASSR and the PTA has been considered, the error in the PTA estimate is about 10 dB. This means that the smallest hearing loss that could be measured would be about 10 dB.
For example, let us assume that a listener produces an ASSR threshold of 40 dB at 1 kHz. Herdman and Stapells found that the ASSR threshold was higher than the PTA threshold, on average by 8 dB at 1 kHz. This gives an estimate of 32 dB for the PTA threshold. The error in this measurement was ± 9 dB, giving a range for the PTA threshold of 23- 41 dB.
Using the graph and equation, formulated by Rance, in 1995, an ASSR threshold of 40 dB at 1 kHz corresponds to a PTA threshold of 21 dB. As 94% of values were within 10 dB of the trend line on the graph, 94% of ears would have a PTA threshold within 10 dB of this figure, giving a range of 11-31 dB.
If the limit for normal hearing is 10 dB, then using the Herdman and Stapells calibration, in order for there to be a hearing loss measured, the predicted PTA threshold would need to be more than 9 dB greater than this limit, i.e. 19 dB.
Similarly, using the Rance calibration, the predicted PTA threshold would need to be 10 dB more than the limit, i.e. 20 dB.
Thus, the smallest hearing losses that can be recorded are 9 and 10 dB, respectively, assuming that the analyst has a preferred and reliable calibration method.
Summary
Like ABR and CERA, studies on ASSR accuracy focus on the comparison between ASSR thresholds and pure tone thresholds. Among hearing impaired subjects, the difference between pure tone thresholds and ASSR thresholds decreases with increasing hearing loss. The relationship between pure tone and ASSR thresholds is also stronger at higher frequencies. Although ASSR thresholds tend to be 10-20 dB higher than pure tone thresholds, if this difference in taken into account, pure tone thresholds can be estimated to within around 10 dB. A study comparing ABR with ASSR found that ABR thresholds were 3 dB closer to pure tone thresholds than ASSR thresholds. However, in listeners with steeply sloping hearing loss, ASSR was more accurate. Another study reported that the pure tone thresholds were closer to the CERA thresholds than ASSR thresholds.
Overall, studies found that ASSR thresholds tend to be higher than pure tone thresholds, by 10-20 dB. Both CERA and ABR testing seem to be slightly more accurate than ASSR. However, ‘next generation’ ASSR techniques have been developed, and these seem to exhibit a different relationship with pure tone thresholds.
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Feature: Reliability of CERA and PTA Testing: Sumner v Turtle Wax Limited (Liverpool County Court, 2018) (BCDN Edition 237)
Judgment has recently been handed down in the noise induced hearing loss case of Sumner v Turtle Wax Limited (2018), in which causation was disputed. In this week’s feature article, we revisit the topic discussed in our most recent feature series, namely the merits of hearing loss testing methods additional to pure tone audiometry (PTA). We examine ruling of the County Court judge on the reliability of PTA and cortical electric response audiometry (CERA) tests, conducted on the claimant in Sumner, for diagnosing hearing loss and establishing causation.
THE FACTS
A 47 year old claimant was exposed to ‘loud and continuous noise’ during her employment, from 1990/01 to 2000/01 and 2004/5 to 2010/11. The claimant was a machine operator, cleaning products for motor vehicles. The types of noise which the claimant was exposed to included ‘bangs, rattling, clanging whooshing and whirring’.
In 2006, midway through the 2nd period of employment, the claimant was supplied with foam ear plugs, which she always wore.
As a result of the ‘very loud’ noise, the claimant communicated with her work colleagues by sign language.
As time went on, it became noticeable that she would ask others to repeat themselves in conversation. It also became more difficult for her to understand conversations with more than 1 speaker and conversations in the presence of background noise. She often missed calls and text messages.
The claimant did not consult the medical opinion of a general practitioner, but brought a claim in 2013, after receiving a call from a company which dealt with hearing loss claims.
The claim alleged onset of NIHL and tinnitus through exposure to excessive noise in the course of her employment.
PRELIMINARY TRIAL
The preliminary trial was heard in December of 2016. Recorder McLoughlin’s judgment was handed down in February of last year. He found that the defendant had breached its duty owed to the claimant.
The claimant was not given breaks from exposure to continuous noise levels. Daily noise levels throughout her employment reached 92 dB, according to noise surveys. However, this measurement was increased by 1 dB, to 93 dB(A) LEP’d, given that she regularly worked 8 hours of additional weekend overtime. This gave a noise immission level (NIL) of 104 dB [NIL = Daily Noise Dose + 10log(Years of Exposure)]. Further, the defendant was in breach of Regulations 4, 6, 7, 8, 9 and 11 of the Noise at Work Regulations 1989.
General damages were agreed between parties at £9,000, without prejudice to causation issues, which were the topic of discussion in the present trial.
PRESENT TRIAL ON CAUSATION
At Liverpool County Court, Recorder David Heaton QC presided over the trial on causation. The main issue was whether the claimant’s PTA and CERA test results constituted reliable diagnoses of NIHL.
Medical Evidence
The claimant completed PTA testing in 2013, 2015 and 2017. Recorder Heaton QC produced an account of the claimant’s experiences of PTA, as follows:
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‘... when she put the earphones on there was a permanent noise which made detecting the additional sounds generated by the testing difficult. The test which she then underwent took the form of what she called a “press the button” test. She pressed the button whenever she heard a sound, as instructed. There were no distractions and she was happy that she had done what was required of her to the best of her ability’.
In 2017, the claimant also underwent 2 CERA tests. The 2nd test arose because there had been objection to the exclusion of 6 kHz and 8 kHz thresholds in the 1st test. Recorder Heaton QC described the claimant’s experiences of CERA, as follows:
‘... the claimant was admitted to a quiet room and given headphones to wear and magazines to read ... there were no other distractions ... Sound signals were introduced into each ear and her brain’s response was monitored by means of electrodes placed on the scalp’.
Figure: Hearing Test Results
Medical Experts
Consultant Audiological and Audio-Vestibular Physician, Dr. Mohammed Iqbal, and Consultant Ear, Nose and Throat Surgeon, Philip Jones, were the instructed medical experts, on behalf of the claimant and defendant, respectively. Both referred to the Coles, Lutman & Buffin (CLB) Guidelines 2000 as the reliable basis for determining causation of NIHL, although Mr Jones criticised the CLB guidelines for stating that losses at 6 kHz ONLY are diagnostic of NIHL.
However, in three joint statements, the medical experts could not reach a consensus on causation, or even the existence of anything more than limited hearing loss.
The experts disagreed on which test was more reliable for diagnosing NIHL. Dr Iqbal, who argued that the claimant had NIHL and tinnitus, relied on CERA testing and disavowed the reliability of any PTA testing. Whereas, Mr Jones, who argued that any limited hearing loss was idiopathic and any tinnitus was sporadic, relied on the 2015 and 2017 PTA test results, as well as literature comparing testing methods. He concluded that CERA was a ‘worse’ measure of hearing loss.
Are PTA Results Reliable for Diagnosing NIHL and Determining Causation?
On this issue, the claimant relied on the expertise of Dr Iqbal, who stated that the PTA test results should not be trusted, as they were inconsistent. He blamed this inconsistency on wax occluding the right ear and tinnitus. However, the defendant contended that neither of these factors were contra-indications to performing PTA, especially as the tinnitus was only mild. Further, if wax had been obstructive, hearing loss would have been conductive, not sensorineural, and an air-bone gap would have been apparent from the PTA results, when it was not. CERA testing results were worse by around 10 dB, which Mr Jones anticipated.
Taking into consideration the opinions of the experts, Recorder Heaton QC stated, at paragraphs 77 and 78:
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‘Having considered all these matters, I have come to the conclusion that Dr Iqbal’s objections are without foundation. The most substantial objection might, in other circumstances, have been in relation to the potentially distorting effect of tinnitus. However, there were three different audiologists involved here. It is reasonable to assume that they all made themselves aware that the Claimant had tinnitus, appropriately advised her, did not have to note any difficulty she raised and were unconcerned about the results obtained. It is also significant that Dr Iqbal advised in favour of another PTA if he really felt that her tinnitus, which had not assumed the status of objection to which not was raised at trial, would distort the results and render nugatory the further investigation.
It follows that I consider that the PTAs of 2015 and 2017 provide a reliable basis for determining diagnosis and causation’.
Can CERA Testing Be Relied Upon as a Stand Alone Basis for Diagnosing NIHL and Determining Causation?
In last week’s edition of BC Disease News (here), we reviewed CERA testing.
CERA is a hearing test that records signals from the auditory cortex (the part of the brain that recognizes sound) when sound is detected. CERA testing is an evaluation of the function of the whole auditory pathway, which signals pass through. The auditory pathway starts with detection, in the cochlea, and ends with processing, in the auditory cortex.
Figure: The auditory pathway143
During testing, the brain’s response to sound, at different frequencies, is measured. Unlike PTA, CERA testing is objective. The patient does not have to ‘decide’ whether or not they have heard the tone. The threshold is defined as the lowest level at which a response is present.
CERA is useful when PTA results are in doubt, exaggerated,144 or are clearly erroneous.
Many studies have calculated the mean error in CERA thresholds (the difference from PTA thresholds) as being within 10 to 15 dB. Research shows that if testing parameters and protocol are chosen with care, the response is capable
143 Song, J. H., Nicol, T. & Kraus, N. Test-Retest Reliability of the Speech-Evoked Auditory Brainstem Response in Young Adults. Clin Neurophysiol 122, 346–355 (2011).
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of being within 10 dB of the PTA response in almost all patients.145 Tsui, Lightfoot and Kennedy, and Prasher found this to be correct in 83.2%, 80% and 84% of patients, respectively.146 147 148
Accuracy can be influenced by drowsiness. As a result, ideal conditions would involve alert patients, which is why patients are given magazines to read during testing, as was the case in Sumner.
In the Sumner case, after having assessed the reliability of PTA, Recorder Heaton QC went on to consider the reliability of CERA as a stand-alone method of testing. Mr Jones said that the role of CERA was to check the accuracy of PTA. Whereas, the claimant’s case rested on CERA being the preferred method of hearing loss testing, when there is inconsistency with PTA.
Claimant Counsel cited page 443 of Lightfoot and Kennedy (1996), which discussed a paper by King et a [1992], wherein the authors stated that ‘UK CERA is the test if choice and is accepted by the courts when objective hearing assessment is required in adult medico-legal cases’. They also cited page 449 of Lightfoot and Kennedy:
‘... in many countries, CERA is used to establish the true hearing thresholds in compensation or war pension veteran] cases where there is a suspicion of non-organic hearing loss’.
By contrast, Counsel for the defendant cited Aldred v Courtaulds Northern Textiles Limited (2012). Recorder Heaton QC agreed with the defendant that CERA testing, in this case, was ‘a cross-check to the PTA results’.
The defendant also referred to CorticalERA.com, which advises that:
'Even where the PTA results are accurate, CERA serves to remove all doubt over their validity ...’
On the issue of CERA reliability, the judge favoured the defendant’s analysis. At paragraph 80, he reasoned:
‘It seems to me that there are circumstances where CERA might be used as the sole diagnostic tool. These, however, would be restricted usually to cases where an adult could not give reliable responses for whatever reason, whether because there is an issue of mental capacity or non-organic hearing loss.
I am not persuaded that it is the diagnostic tool of choice for obtaining accurate true threshold hearing levels in most cases of alleged NIHL, including this case. The evidence before me suggests that it is only where there are inconsistencies and/or differences in PTA results that CERA has been resorted to and only then to validate the PTAs where the true and accurate thresholds have already been measured but require verification. It was never intended in 2017, when the further audiometry tests were ordered that the existing PTAs should be set to one side and CERA alone relied on. If that had been the case why did Dr Iqbal request a further PTA? Indeed, Dr Iqbal had already stated that one of the existing audiograms of 2013 or 2015 was probably accurate and reliable.
‘... It [CERA] cannot deliver results as to true hearing thresholds. The most that it can do is to be used to verify otherwise reliable PTA results. I am satisfied that PTA is the primary and more accurate diagnostic tool. CERA was not used to obtain true thresholds in Aldred. Further, despite the literature produced, there is no deafness litigation case in which it has been reported to have been used other than to validate a PTA result or results.
145 Stapells DR. Threshold estimation by the tone-evoked auditory brainstem response: a literature meta-analysis. Journal of Speech Language Pathology and Audiology. 2000;24(2):74-83
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It seems to me that the CERA can be used in this case as a verification tool in relation to the PTAs. I reject the invitation to use the figures generated by CERA testing as if they are accurate, as opposed to estimated, hearing thresholds’.
Did the Claimant Have NIHL?
Having passed judgment on the reliability of PTA and CERA testing alone, the judge made his determination, at paragraph 89, on whether the tests were diagnostic of hearing loss. Recorder Heaton QC noted an ‘absence of hearing loss in the form of a diagnostic notch in either ear at 4 kHz in 2015 or 2017’. He went on to conclude:
‘I have considered the gaps between the PTA threshold and the estimated results, as I have found them to be, in the CERA results at 1, 2, 3 and 4 kHz, those being the levels at which Dr Iqbal contended that the Claimant had NIHL. None of those gaps exceeded 10 dB. This was within verification limits. The Claimant had generally good hearing, according to the 2017 results. Where hearing level thresholds are near to normal it appears to be accepted that the provision of the objective threshold on CERA testing is poorer. This is in line with Mr Jones' evidence that CERA thresholds are nearly always worse, and never better, than the PTA thresholds.
It follows that I do not accept that the CERA results provide a satisfactory or reliable evidential basis by way of true hearing thresholds for establishing causation’.
Hearing Loss Onset 25 Years Post-Noise Exposure: Harte v Hawker Siddeley Dynamics Ltd & 2 Ors (Wigan County Court, 2018) (BCDN Edition 240)
In the case of Harte v Hawker Siddeley Dynamics Ltd & 2 Ors (Wigan County Court, 2018), an engineer, employed for a total period of 30 years, was unsuccessful in pursuing a NIHL claim against 3 defendants, arguing that exposure to excessive noise in the course of his employment was the cause.
The 1st and 2nd defendants reached settlement with the claimant pre-trial. However, the 3rd defendant contested the claimant’s claim on medical causation.
The claimant worked for the 3rd defendant from 1980 to 1986, a period of 6 years. For the first 5 years, the claimant was posted in a workshop with 40 employees. He then spent his final year in a different workshop, among just 7 employees.
His job entailed the service and repair of switchgear systems and motors. He used ‘a compressed air nut gun, disc grinder drills and hammers, in close proximity to other fitters, 8 hours a day, 5 days a week, and most Saturday mornings as overtime’.
The claimant was not supplied with hearing protection and was given no advice on health and safety. As such, breach of duty was conceded.
The claimant first noticed his hearing loss in 2012, aged 72. From this point onwards, the claimant noticed ‘markedly worse’ hearing.
Consultant ENT surgeons, Arvind Arya and Philip Jones were instructed on behalf of the claimant and defendant, respectively, while Consultant acoustic engineer, Mike McLoughlin was employed as a single joint expert.
Mr McLoughlin measured the workplace Noise Immission Level (NIL) at 105 dB(A), with noise exposure ranging between 93 and 107. Claimant counsel argued that the NIL was up to 113 dB(A) and no lower than 100 – the minimum noise exposure such as to expose the claimant to a risk of NIHL.
In a Joint Medical Statement, both the claimant and defendant experts agreed that:
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‘(i) Mr Harte was suffering from some age associated hearing loss (“AAHL”) and (ii) that noise induced hearing loss (“NIHL”) is “irreversible” and neither occurs nor progresses in the absence of continued exposure without adequate protection and (iii) that the Claimant would benefit from hearing aids’.
In spite of joint medical advice, the claimant refused to wear hearing aids.
Audiometric testing was conducted twice, firstly in 2015 and secondly in 2017. Mr Recorder Parrington accepted the 2015 audiogram as the more relevant set of results, as less time had elapsed since the alleged onset of hearing loss.
Mr Arya noted bilateral, sensorineural, mildly asymmetrical hearing loss, which was worse at high frequencies. He observed a downward notch at 4 kHz. In the right ear, hearing loss was at least 10 dB greater at 3, 4 and 6 kHz thresholds than at 2 kHz. In the left ear, hearing loss was at least 10 dB greater at 4 and 6 kHz thresholds than at 1 and 2 kHz.
Referring to the CLB Guidelines 2015, the claimant’s expert observed high frequency sensorineural hearing impairment, fulfilling R1; a history of continuous exposure to noise, likely fulfilling R2(a); and a downward notch in both ears in the 3 to 6 kHz range (4 kHz), fulfilling R3.
Mean hearing loss at 1, 2 and 3 kHz was 26.7 dB in the right ear and 29.4 dB in the left ear. With AAHL (Presbycusis) for a 75 year old being 16.7 dB, mean NIHL was calculated at 12.7 dB. As such, Mr Arya diagnosed the claimant with NIHL due to excessive noise and AAHL.
Counsel for the defendant questioned Mr Arya on an additional 20 dB notch at 1 kHz, but he could not account for this. Questions were also raised over the 25-year period between the cessation of noisy employment with the 3rd defendant and the alleged date of hearing loss development. Mr Arya accepted that hearing loss could be idiopathic, accounting for 2.5 dB of the original 12.7 dB NIHL calculation. His NIHL calculation was therefore reduced to 10.1 dB.
Counsel for the claimant submitted that, in terms of hearing loss of 2, 3 and 4kHz, which they considered to be the ‘critical frequencies’, the claimant’s hearing loss could be calculated at 8 dB.
Mr Jones, on the other hand, calculated the claimant’s NIHL at 3.3 dB, as argued by defendant counsel at trial.
An average of both expert NIHL calculations (10.1 dB and 3.3 dB) gave a figure of 6.7 dB. Mr Arya sought to argue that any loss above 4 dB would be ‘significant’ and therefore actionable. It was claimant counsel’s argument at trial that any loss above 6 dB was compensatable.
By contrast, Mr Jones considered that a 3 dB loss would be ‘insignificant’ and therefore de minimis.
At trial, counsel for the defendant referred to the McShefferty Papers, which were examined in edition 233 of BC Disease News (here). McShefferty submitted that losses below 5 dB are barely perceptible and have no noticeable effect on speech in noise. The defence also relied on papers written by Lacroix and Harris and by Aniansson, which ‘indicate that a loss of 50dB at 4 kHz and above causes a “decrease of just under 1% in the ability to perceive speech in noise…”’
Mr Jones was also of the opinion that the length of delay could not lead to a positive NIHL diagnosis:
‘... any reasonable audiogram is of doubtful validity in trying to diagnose NIHL which would have been present in full over 30 years’.
In the 2-year period between the 1st and 2nd audiometric testing, Mr Jones stated that hearing loss progression could not be attributed to noise exposure. Further, he argued that the difference between the right and left ears in testing was ‘not acceptable for symmetrical exposure’, especially at noise sensitive frequencies. He was of the mind that asymmetry was an indicator that NIHL was ‘less likely’, whereas Mr Arya believed that ‘asymmetrical loss does not preclude a person from having noise related hearing loss’. What is more, Mr Jones argued that that the claimant’s notch at 1 kHz could not be noise-related.
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The defendant’s medical expert therefore concluded that:
‘... perhaps it would be equitable to conclude there is a minor NIHL present which he has never noticed and which on objective criteria would not be judged as significant’.
In coming to his decision, the Recorder had ‘no doubt that the assessment as to NIHL has not been made easier by 2 factors namely (i) the lapse of time between 1986 when exposure ceased to 2012 when the Claimant first noticed a hearing loss, more than 25 years later, and (ii) the onset of AAHL as the Claimant entered his later years’.
He found in favour of the defendant and Mr Jones, on causation. At paragraphs 45 to 49, he reasoned:
‘In my judgment, I find that noise exposure during the period 1980 – 1986 was such as to cause the Claimant a noise induced hearing loss; the engineer’s evidence is that exposure to noise exceeding the limits for which hearing protection is required occurred.
It is clear however that the Claimant was not aware of any loss, whether NIHL, age related loss or idiopathic loss, before April 2012, that being more than 25 years after the noise exposure ceased. Furthermore, there is no medical evidence which purports to demonstrate such a loss before 2012.
I accept that the effect of noise exposure may not manifest itself until some years after the cessation of exposure. I accept that the audiogram of 2015 exhibits a notch of 4 kHz in both ears, that being indicative of NIHL but also there is a notch of 1 kHz which is agreed is not indicative of NIHL. I am also satisfied that the 2015 audiogram demonstrates asymmetry more marked in the noise sensitive frequencies which makes bilateral NIHL less likely.
However, I find it a fact that Mr Harte’s hearing loss for the period 2012 – 2015 (and beyond) can substantially be ascribed to a non-noise, age related loss. It is unfortunate that Mr Harte has failed to act on the medical opinion of the experts to obtain and use hearing aids which these days can be obtained free of charge on the NHS which are both advanced in technology and are unobtrusive – there seems little doubt that his quality of life would be changed for the better, however that must be his choice.
On balance, I find that having regard to the lapse of more than 25 years, the evidence as to advancement of non- noise loss, particularly age-related loss, the asymmetry demonstrated within the audiograms and the Claimant’s own perception of hearing loss, that Mr Jones’ opinion is to be preferred. Such loss of hearing as can be ascribed to noise exposure was not in my judgment sufficient as to be described as significant and such diminution in the Claimant’s hearing as was caused by exposure to noise did not make the Claimant’s ability to hear appreciably worse’.
Feature: A Review of De Minimis in NIHL Claims Post-Dryden: Nicholls v Osram Ltd & Anor (Newcastle County Court, 2018) (BCDN Edition 241)
In this feature article, we consider the current position of de minimis in NIHL claims.
In edition 224 of BC Disease News (here), we reported on the case of Dryden and others (Appellants) v Johnson Matthey Plc (Respondent) [2018] UKSC 18, where the Supreme Court created uncertainty over de minimis as a ground of defence. Here, the claimant’s physiological changes, namely sensitisation to platinum salts, constituted ‘actionable damage’, despite not being ‘harmful in itself in any relevant sense’.
However, in last week’s edition (here), we reported on the case of Harte v Hawker Siddeley Dynamics Ltd & 2 Ors (Liverpool County Court, 2018), in which NIHL was considered not to have been ‘sufficient as to be described as significant’ and ‘did not make the Claimant’s ability to hear appreciably worse’.
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Since then, we have received draft judgment on the case of Nicholls v Osram Ltd & Anor (Newcastle County Court, 2018), where both defendants contended a NIHL claim on the basis that incremental changes in hearing threshold were not ‘significant’ such as to make the claimant ‘appreciably worse off’.
DRYDEN AT THE UK SUPREME COURT
In the case of Dryden, the claimant developed platinum salt sensitisation, an asymptomatic condition caused by exposure to platinum salts. However, sensitised individuals are at risk of allergic reaction upon further exposure to chlorinated platinum salts.
In previously accepted law on de minimis, the House of Lords found that asymptomatic pleural plaques (fibrous thickening of the pleural membrane which surrounds the lungs) did not constitute an ‘actionable injury’. The Court in Rothwell v Chemical & Insulating Co Ltd [2008] AC 281) reasoned that pleural plaques were ‘symptomless bodily changes with no foreseeable consequences’. In Dryden, the medical experts compared platinum salt sensitisation with pleural plaques:
‘i. Slight further exposure to asbestos will not materially worsen pleural plaques, but slight further exposure to platinum salts is likely to increase the degree of sensitisation and may result in asymptomatic sensitisation becoming symptomatic; ii. Pleural plaques do not, themselves, turn into any other injury attributable to asbestos whereas asymptomatic sensitisation mayturn into symptomatic sensitisation (allergy); iii. The presence of pleural plaques does not prevent a person from engaging in particular types of work that would otherwise be open to him or her, asbestos exposure being restricted by law in any event. In contrast, a person who has asymptomatic sensitisation to platinum salts is restricted in the work that he or she can do’.
The Supreme Court overruled the 1st instance and Court of Appeal decisions, in favour of the claimant. Even though the 1st instance judge, Mr Justice Jay, differentiated between sensitisation (a ‘direct causal pathway’) and pleural plaques (a ‘biological cul-de-sac’), he still found that ‘nothing short of actual symptoms could amount to actionable injury’. At paragraphs 47 and 48 of the Supreme Court judgment, Lady Justice Black distinguished Rothwell from Dryden and cast doubt on any future success of defending claims (potentially including NIHL and HAVS), on de minimis submissions:
‘I would distinguish this case from Rothwell ... As I see it, it is material that the pleural plaques were nothing more than a marker of exposure to asbestos dust, being symptomless in themselves and not leading to or contributing to any condition which would produce symptoms, even if the sufferer were to be exposed to further asbestos dust. Similarly, the sensitisation of the claimants in this case marks that they have already been exposed to platinum salts, but unlike the plaques, it constitutes a change to their physiological make-up which means that further exposure now carries with it the risk of an allergic reaction, and for that reason they must change their everyday lives so as to avoid such exposure. Putting it another way, they have lost part of their capacity to work or, as the claimants put it in argument, they have suffered a loss of bodily function by virtue of the physiological change caused by the company’s negligence.
As Lord Pearce said in Cartledge (supra para 15), it is a question of fact in each case whether a man has suffered material damage by any physical changes in his body. It is a question of fact that must be determined in the light of the legal principles applicable to personal injury actions ...’
HARTE JUDGMENT ON DE MINIMIS IN NIHL
However, last month, judgment was handed down in Harte v Hawker Siddeley Dynamics Ltd & 2 Ors (Liverpool County Court, 2018), in which the claimant was unsuccessful at trial against the 3rd defendant employer, which employed him 25 years prior to NIHL attribution.
Consultant ENT surgeons, Arvind Arya (instructed by the claimant) and Philip Jones (instructed by the defendants) observed the better 2015 audiogram and calculated NIHL at 10.1 dB and 3.3 dB, respectively. Both medical experts also noted a notch at 4 kHz in both ears.
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Mr Araya submitted that any loss above 4 dB would be ‘significant’ and therefore actionable. It was claimant counsel’s argument that any loss above 6 dB was ‘compensatable’, while Mr Jones asserted that a 3 dB loss was ‘insignificant’ and therefore de minimis.
Mr Jones argued that hearing loss development between attribution and the 1st audiogram was likely to have been substantially ascribed to AAHL, given the long lapse between noise exposure and attribution. Unlike Mr Araya, he was of the mind that asymmetry presence was an indication that NIHL was ‘less likely’. Nevertheless, Mr Jones conceded:
‘... perhaps it would be equitable to conclude there is a minor NIHL present which he has never noticed and which on objective criteria would not be judged as significant’.
Recorder Parrington found in favour of the defendants' analysis, namely that noise-related hearing loss was de minimis:
Such loss of hearing as can be ascribed to noise exposure was not in my judgment sufficient as to be described as significant and such diminution in the Claimant’s hearing as was caused by exposure to noise did not make the Claimant’s ability to hear appreciably worse’.
THE LATEST CASE OF NICHOLLS
In Nicholls v Osram Ltd & Anor (Newcastle County Court, 2018), the claimant pursued a claim against 2 defendant employers. It was alleged that the claimant had developed hearing loss attributable to excessive noise exposure. The claimant was employed by the 1st defendant, from 1978 to 1984, and subsequently by the 2nd defendant, from 1987 to 1990.
Limitation was conceded pre-trial. However, breach of duty was contested by the 1st defendant, which did not provide the claimant with hearing protection, nor training on the dangers of working in a noisy environment.
During the period of employment at the 1st defendant’s factory, the claimant worked on lightbulb producing machines and packing machines, with high pressure pumps. These machines were left running for the duration of his shifts, at an arm’s length. The claimant alleged that he had to shout, or raise his voice, to communicate with colleagues stood 4ft from him.
Single joint expert and acoustics engineer, Daniel Saunders, produced a report on the expected noise exposure. He determined that the claimant’s Noise Immission Level was between 94 and 104 dB. Moreover, he calculated that the daily noise dose, during the course of employment with the 1st defendant, would have been between 87 and 90 dB(A), neither of which were in excess of the 90 dB(A) LEP,d requirement under the 1972 Department of Employment document: Code of Practice for Reducing the Exposure of Employed Persons to Noise. Mr Saunders concluded that the daily noise exposure levels were ‘likely to have been above 90 dB(A)’.
However, District Judge Morgan found that the engineer’s conclusion was not consistent with the 87 to 90 dB(A) range of values derived earlier in his report. As such, the claimant had failed to establish a breach of duty against the 1st defendant and the claim against the 1st defendant failed.
In any event, the 2nd defendant conceded on breach of duty. As such, the judge went on to consider the issue of de minimis in NIHL.
Joint medical statement was given by claimant expert, Mark Yardley, and defendant expert, Andrew Parker, on 12 October 2016. This was in relation to a single joint audiogram, taken on 19 July 2014.
Mr Yardley’s Position Pre-Joint Statement
In his initial report, Mr Yardley referred to the CJ Moore Paper on 4 kHz and the importance of hearing thresholds at this frequency, for the purpose of perceiving speech: ‘A review of the perceptual effects of hearing loss for frequencies above 3 kHz’. On this basis, he calculated NIHL of 13 dB, in the right ear, at 4 kHz. Noting asymmetrical
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loss, he accepted that the results of the less deafened right ear would be more appropriate for calculating losses across a range of frequencies.
Average arithmetic hearing loss in the right ear, across 1, 2 and 3 kHz, was calculated at 8.3 dB, using the conventional Coles Guidelines (CLB 2000) method. However, Mr Yardley preferred a hearing loss calculation across 1, 2 and 4 kHz, which was 18.3 dB. His reason for doing so was his observation of ‘relatively well preserved hearing in the lower frequencies but a significant loss at 4 kHz bilaterally’.
Using ISO 7029 Table 1, AAHL (Presbycusis) for a 50th percentile 51-year-old male, was extrapolated as 8.3 dB – the same as the initial NIHL calculated figure across 1, 2 and 3 kHz.
Mr Parker’s View of Mr Yardley’s Initial Assessment in the Joint Statement
Mr Parker did not accept the Mr Yardley’s reliance on the research of CJ Moore, nor did he accept the AAHL figure of 8.3 dB, suggesting an alternative figure of 10.7 dB.
By contrast, he relied on the McShefferty Papers, which we examined in detail in edition 233 of BC Disease News (here) and were successfully adduced by Mr Jones in Harte. McShefferty considered that ‘just noticeable’ and ‘just meaningful’ difference of speech in background noise was far greater in both hearing-impaired and non-hearing- impaired individuals than initially considered.
Mr Parker offered alternative calculations, using the latest guidance from Professor Lutman, et al: ‘Guidelines for Quantification of Noise Induced Hearing Loss in a Medicolegal Context’ (LCB 2015). Applying the LCB ‘short method’ and ‘full method’ across 1, 2 and 3 kHz produced binaural hearing losses of 2.2 dB and 3.5 dB, respectively.
Mr Parker found that the degree of hearing loss calculated by applying Professor Lutman’s method was ‘not material’ and would not have left the claimant ‘appreciably worse off’.
Joint Statement Consensus of Both Mr Yardley and Mr Parker
In their joint statement, both medical experts were in agreement that the claimant, aged 51, would have suffered ‘some degree’ of AAHL. Mr Yardley reconsidered his initially reported NIHL calculations and accepted that the correct calculation would apply Lutman’s ‘full method’ across 1, 2 and 3 kHz (3.5 dB NIHL), as per the suggestion of Mr Parker. Mr Yardley extended Mr Lutman’s method to present a loss of 6.4 dB across 1, 2 and 4 kHz. He contended that 3.5 dB binaural hearing loss was ‘not a great loss’, neither was it ‘insignificant’.
However, both experts agreed that R1 of the CLB Guidelines was met, namely that there was high frequency, bilateral sensorineural hearing loss. Further, a significant notch at 4 kHz was identified bilaterally, satisfying R3(A) of the Guidelines. R2 was also satisfied.
Cross-Examination Post-Joint Statement
Under cross-examination, Mr Yardley accepted that Table 2 of the ‘Guidelines on the Diagnosis of Noise Induced Hearing Loss for Medicolegal Purposes’ (CLB 2000) would have been a better way to assess AAHL than Table A1 of the Black Book. He further accepted that his calculation of 6.4 dB binaural deafness, across 1, 2 and 4 kHz, was an ‘oversight’.
Across 1, 2 and 3 kHz, the right ear exhibited 3.3 dB of loss, but Mr Yardley accepted that variation ‘from person to person’ would make it ‘difficult to quantify’ whether the claimant would have been ‘worse off’. Mr Yardley stated that, generally speaking, if losses are greater than 5 dB, claimants can be deemed to be ‘worse off’. Equally, if losses are less than 2 dB, claimants cannot.
Mr Parker, when questioned by DJ Morgan about his dismissal of the CJ Moore Paper, reasoned that Moore’s research had initially been presented as a letter and later became a publication. Thus, it was unreliable.
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Findings of DJ Morgan
DJ Morgan cited the relevant case authorities, beginning with Lady Justice Black, in Dryden. He also cited Roberts v Prysmian Cables and Systems Limited (2015) and Briggs v RHM Frozen Foods Limited (2015). Both of these cases featured in a tabular representation of County Court decisions on de minimis in NIHL, which was included in edition 216 of BC Disease News here. In that article, we considered the judgment in Evans v Secretary of State for the Department of Energy & Climate Change and JJ Maintenance Limited (2017).
In Evans, the judge preferred the claimant expert’s (Mr Singh) NIHL calculation, taken across 2, 3 and 4 kHz, producing an ‘appreciable’ hearing loss of 11.2 dB. The defendant expert’s (Professor Lutman) calculation across 1, 2 and 3 kHz (2.3 dB), in this instance, was disregarded.
Nevertheless, the District Judge in Nicholls found that the claim against the 2nd defendant had to fail. The claimant was not ‘appreciably worse’ off as a result of his NIHL.
He found the defendants’ expert to be far more persuasive than the claimant’s. Mr Parker was ‘not swayed’ under cross-examination, whereas Mr Yardley’s hesitant approach made him a ‘less compelling witness’. The judge hastened to add that his comments were an attack on Mr Yardley’s ‘reliability’ and not his ‘credibility’.
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At paragraphs 72 to 75, District Judge Morgan reasoned:
‘I find therefore, relying upon evidence of Mr Parker, that the claimant has not established that with the hearing loss of 3.3 dB in his right ear at 1, 2 and 3 kHz that makes him appreciably worse off. The evidence of the claimant does not assist in this case as he cannot give evidence as to how much worse off he is than if he suffered loss only as a result of presbycusis. That is a matter for the experts and ultimately for the court.
In respect of a finding that the court is invited to make that there should be reliance upon the results of hearing loss higher frequencies of 1, 2 and 4 kHz I again prefer the evidence of Mr Parker supported by the McShefferty Papers. Mr Yardley opines that 4 kHz is an important frequency to discern speech in particular if there is background noise (the claimant has in effect noise induced hearing loss of about 13 dB in his better right ear at that frequency relying on Professor Moore’s paper).
There is clearly a range of views upon this issue which has been around for many years but the recent and ‘traditional’ method of assessing disability is 1, 2 and 3 kHz reinforced in the 2015 Guidelines which both the experts agree in the joint statement ‘that a reasonable method of estimating the degree of noise induced hearing loss’ are the methods described in those Guidelines.
I am not persuaded upon the evidence before me that it is appropriate to depart from the 2015 Guidelines. Even if I were to be wrong in that respect I accept the evidence of Mr Parker again that the claimant does not demonstrate that he is appreciably worse off as the change in his hearing at the frequency of 4 kHz is insignificant’.
CONCLUSIONS
The recent NIHL judgments of Harte and Nicholls appear to have diminished fears that the Supreme Court authority of Dryden has ended de minimis as a defence in industrial disease claims.
It is also worth recognising several similarities between the judgments of Harte and Nicholls: • The robustness of medical expert reporting affected the ‘reliability’ of evidence, thereby influencing the success of de minimis arguments. • A test across 1, 2 and 3 kHz, using Professor Lutman’s ‘full method’, provided the most accurate calculations of NIHL. • The Moore Paper on the importance of notches at 4 kHz proved unsuccessful when attempting to escape de minimis – this also reduced the likelihood that calculations of NIHL across 1, 2 and 4 kHz would be accepted. • The McShefferty Papers on ‘noticeable’ and ‘meaningful’ difference of speech in background noise are gaining traction and bolstering de minimis as a defence – claimants must prove how much ‘worse off’ they are, which is ‘difficult’ when NIHL is only a couple of decibels. • Asymmetrical hearing loss positively impacted upon de minimis arguments; the same can be said for Presbycusis – the better ear was the more reliable ear.
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Feature: Maximum Bulging at 2 kHz: Callaghan v Imperial Chemical Industries Limited & Anor (2018, Middlesbrough County Court) (BCDN Edition 243)
In this week’s feature, we provide detailed analysis of the judgment in Callaghan v Imperial Chemical Industries Limited & Anor (2018, Middlesbrough County Court), a noise-induced hearing loss (NIHL) case. BC Legal was instructed to act for the 2nd defendant’s EL insurer and judgment was handed down in June of 2018.
At the trial, His Honour Justice Mark Gargan dealt with issues on: • Noise exposure levels; • Breach; • Limitation; and • Medical causation.
FACTS
The claimant in this case was a 59-year old welder, who was employed between 1982 and 1995 in a fabrication shop at industrial premises. He worked for various employers during this period. However, the claimant argued that the 2nd defendant was responsible for any breach of duty.
Consequently, the claimant sought damages for personal injury, alleging that he had developed NIHL as a result of excess noise exposure at the 2nd defendant’s premises.
It is worth noting that the claimant had already resolved a claim brought against the 1st defendant, which employed the claimant between 1975 and 1981.
NOISE LEVELS
Mr Stephen Watts was appointed to act as joint-expert acoustic engineer.
In his report, he noted that, irrespective of the type of work conducted by the claimant, typical background noise levels in a fabrication shop would have been between 85 dB(A) and 90 dB(A).
Cross-checking against a copy of the claimant’s pleadings and witness statement, Mr Watts asserted that the claimant would have spent 60% of his time welding and 35% of his time grinding. However, he also assessed that the claimant would only have spent between 1 and 1.5 hours of his shift actively grinding or welding (‘anger time’), after applying a 50% reduction. Ultimately, his report stated that the claimant’s daily noise dose was ‘probably as high as about 94 dB (A) if he was working in a reasonably busy fabrication shop with the overtime he described’.
As such, he concluded that the claimant’s lifetime noise dose would be around 106.6 dB NIL [Noise Immission Level (NIL) = Daily Noise Dose + 10log(Years of Exposure).
BREACH OF DUTY
HHJ Gargan firstly discussed submissions on breach, without prejudice to later findings on s.33 of the Limitation Act 1980. Breach was considered before limitation, since the defendant accepted that the court was likely to establish breach on the evidence available.
The judge concluded that, ‘on the balance of probabilities, the claimant was regularly exposed to noise in excess of 90 dB(A) without the benefit of hearing protection’.
Pursuant to the 1972 Code of Practice, HHJ Gargan found that the 2nd defendant was in breach of duty and exposed the claimant to excessive noise.
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LIMITATION
Limitation Period
It was agreed that any injury the claimant sustained as a result of noise exposure (‘cause of action’) was complete when exposure came to an end in 1995.
Pursuant to s.11(4)(a) of the Limitation Act, the primary limitation period therefore expired in 1998, subject to a later ‘date of knowledge’.
Was the claimant’s ‘date of knowledge’ within 3 years of 2 September 2015, when the claim was filed at court?
Knowledge
The claimant submitted that he did not realise he was suffering from any ‘significant’ hearing loss until shortly before he visited his GP in October 2012 and did not attribute his hearing loss to noise exposure until he saw his GP and/or was seen in the ENT clinic in November 2012.
The claimant’s GP noted the following:
Here, ‘getting worse’ implied that the claimant had been aware of hearing losses for some unspecified period of time before the consultation.
Subsequently, Miss Iqbal, at the ENT clinic, recorded:
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The claimant must therefore have noticed problems with his hearing at least 6 to 7 years before 2012.
Then, in a November 2013 medical report, drafted by Mr Yardley, he stated the following:
Consistent with the observations of both the GP and ENT clinician, the claimant noticed hearing loss years before it became ‘significant’. However, pinpointing the date of first appreciation of hearing loss was ‘opaque’.
In answers to Part 18 replies, the claimant specified that he began to notice both hearing loss deterioration and tinnitus ‘a few years ago’, but was ‘unable to pinpoint an exact date’, as his hearing ‘deteriorated gradually’.
In witness statements, dated 28 October 2016, the claimant admitted to noticing hearing deterioration in the ‘last four years’ and became aware of ‘significant’ hearing loss in ‘the last few years’, when he often found himself asking others to repeat themselves in the presence of background noise. Before that, he attributed any deterioration in hearing to his age.
The claimant maintained that he sought the advice of his GP ‘to investigate further’ his ‘significant’ condition and only attributed his hearing loss and tinnitus to noise exposure at work when the ENT clinician advised as such.
On cross-examination, defendant counsel averred that the claimant must have realised that the ear plugs, provided by the 2nd defendant in the 1980’s, were supplied to protect his hearing. The claimant answered that ‘he had realised that the ear plugs were provided to protect his hearing from noise but not that the noise could damage his hearing’. This was construed as meaning:
‘... the claimant accepted that he had realised that noise could damage an individual’s hearing but ... did not realise his hearing had been damaged by noise’.
HHJ Gargan considered the claimant to be a ‘forthcoming’ witness when discussing the nature of his work, but ‘guarded’ when recalling recent hearing loss development. The judge saw this as a reflection of the claimant’s ‘awareness of the difficulties faced in overcoming the potential limitation defence’.
Noting inconsistencies across the claimant’s evidence, he concluded, in respect of first onset of hearing loss and tinnitus onset:
‘... I consider that the claimant’s tinnitus probably began at or about the same time as he became aware of his other hearing difficulties, namely 6 or 7 years before the consultation [ENT] ... I consider that this finding is consistent with the claimant’s comment to Mr Yardley that the symptoms had been present for several years. Therefore, I find that the claimant first recognised that he had hearing problems / tinnitus some time around November 2005 / November 2006. In my judgment, it is appropriate to take the mid-point of that range and therefore I fix the date at 31 May 2006’.
When would a ‘reasonable person’ have considered the claimant’s hearing problems to be ‘objectively significant’? HHJ Gargan accepted that this would not occur ‘on the first occasion that they were experienced’ but would occur ‘after 12 months of experiencing such problems’, i.e. by 31 May 2007.
In respect of attribution, the judge had to decide ‘whether the claimant knew that his symptoms were capable of being attributed to noise such that it was reasonable for him to investigate whether he had a case against the defendant’.
In his judgment, he deliberated that that the ‘most likely explanation’ was that the claimant would have had ‘actual knowledge’ from the time he knew his symptoms were ‘significant’, i.e. 31 May 2007.
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Applying an additional year of ‘thinking time’, allowed by Smith LJ in Johnson v Ministry of Defence [2012] EWCA 1505, HHJ Gargan found that a reasonable man, with the claimant’s symptoms, would have consulted their GP and been alerted to the possibility that hearing loss could be attributed to noise by 31 May 2008, thereby obtaining ‘constructive knowledge’.
As a result, the limitation period expired on 31 May 2010, if the date of ‘actual knowledge’ was correct, or 31 May 2011, if the date of ‘constructive knowledge’ was preferred. The Claim Form was therefore filed at least 4 years after limitation expired and the claim was statute barred, subject to the exercise of s.33 discretion.
Lifting the Limitation Bar
HHJ Gargan considered the s.33(3) factors in turn, such as: a. Delay
The judge observed a delay of around 11 months between the appointment of solicitors and receipt of the medical report, when the expected period was between 3 and 6 months. He also noted a lack of explanation as to why proceedings were not issued until nearly 2 years after the medical report had been obtained. b. Cogency of Evidence
The 2nd defendant ceased trading in 2000, but continued to file accounts as a dormant company until 31 December 2010. During this 10-year period, the company dealt with claims for personal injury brought by former employees.
In light of this, the judge found that the 2nd defendant would have been ‘significantly better able to investigate the claim’ in 2010/2011 than in 2015. A director would still have been in place, access to material documents relating to noise exposure/surveys would have been more possible than when the company was dissolved and it would have been easier to trace witnesses, who would have been in a better position to give evidence on questions of exposure and hearing protection.
Delay after the expiry of limitation, therefore, had ‘significantly affected the cogency of the defendant’s evidence’. What is more, the judge found that the claimant’s ability to recall events would have diminished over the period of delay.
The Balancing Exercise
In undertaking the balancing exercise of whether it was ‘fair just and reasonable in all the circumstances to expect the defendant to meet the claim on the merits’, HHJ Gargan also considered the question of proportionality. He found that this was a ‘relatively modest claim’ with ‘disproportionately substantial’ costs. In view of comments already made on s.33(3) factors, the judge did not grant s.33 discretion to lift the limitation bar.
CAUSATION
Despite ruling that the claim was statute-barred, the judge still considered arguments on causation.
Medical experts, Mr Yardley and Mr Parker, were instructed on behalf of the claimant and defendant, respectively. Both experts were in agreement that the CLB Guidelines (2000) were the principal diagnostic tool for medicolegal purposes.
R1
The experts agreed that the first requirement was satisfied. There was a measurement of hearing threshold level at 3, 4 or 6 kHz at least 10 dB greater than at 1 or 2 kHz, demonstrating high frequency sensorineural hearing impairment.
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R2(a)
As already discussed in the section on noise levels, NIL was assessed by Mr Watts at 106 dB. As such, this was not disputed by experts and the second requirement was satisfied. HHJ Gargan noted that:
‘... at least 50% of individuals exposed to this known or estimated amount of noise [in excess of 100 dB(A)] would be likely to suffer a measureable degree of hearing loss’.
R3(a)
The third requirement of CLB is met if it can be said with confidence that there is a downward notch in the 3 to 6 kHz range.
Usefully, Mr Parker gave a helpful and undisputed description of notching and bulging in the claimant’s audiogram, comparing the shape produced by a notch to an ‘arrow-head’:
‘...a bulge occurred where the hearing frequencies to either side of the point of the arrow were also affected (whether by noise or other factors), so that the V shape produced by the notch is flattened out’.
Difference of medical expert opinion on the third component is set out below.
Mr Yardley’s Diagnosis
Mr Yardley measured the claimant’s average binaural hearing loss at 41.9 dB, with 19.9 dB of losses attributable to noise exposure.
Further, he observed a binaural bulge at 3 kHz, in addition to a bulge at 4 kHz in the left ear. However, he noted that the bulge in both ears was greatest at 2 kHz. Although loss at 2 kHz was greater than expected in a case of NIHL, he relied on CLB 2000, which states that:
The CLB Guidelines were based on ‘population average data’, which showed 4 kHz to be the most sensitive frequency to noise. Mr Yardley proposed that this did not prevent some individuals with NIHL being most severely affected by noise at other frequencies, e.g. 3 kHz or 2 kHz. In this way, the claimant’s medical expert attempted to construe the Guidelines as ‘simply guidelines’ and not as ‘formal rules’.
He refused to diagnose the claimant’s hearing loss as idiopathic and drew support from the fact that, even though the claimant’s bulge calculation was highest at 2 kHz, the claimant’s hearing loss threshold was not highest at 2 kHz.
Mr Yardley cited an academic paper, written by George A Gates: Longitudinal threshold changes in older men with audiometry notches.
Gates observed less change, over a 15-year period, across the range of 3 to 6 kHz and significantly greater change over time at 2 kHz when notches at 3 to 6 kHz were measured above 35 dB, compared with less significant notches. Findings of increased loss at 2 kHz were suggestive that the effects of noise damage ‘may continue long after the exposure has stopped’. Gates presumes that the mechanism for continued hearing threshold losses at 2 kHz is probably the result of ‘prior noise induced damage to the cochlea’, but this is not scientifically proven.
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Defendant counsel criticised the Gates Paper, on the basis that ‘most experts’ accept that hearing damage, caused by noise, stops upon cessation of exposure, until the reservoir of hearing capacity is further depleted by age-associated loss (AAHL or Presbycusis).
My Yardley, in response, cited animal studies as confirmatory research of the Gates Paper findings, but was unable to cite any human studies.
Applying the CLB Guidelines Note 10 bulge calculation method, Mr Yardley considered that a lower anchor point was more appropriate if the hearing threshold level was 5 dB better at 1 kHz before the adjustment for age- associated losses.
Mr Parker’s Diagnosis
Like Mr Yardley, Mr Parker calculated the claimant’s average non-age-related binaural hearing loss at 20 dB. However, he did not attribute this impairment to noise exposure. He criticised Mr Yardley for only considering noise and age as potential causes for the claimant’s hearing impairment.
He cited Linda Luxon and Deepak Prasher: Noise and Its Effects and Advances in Noise Research – Volume 1 – Biological Effects of Noise. The purpose of this was that the authors identified 12 causes of sensorineural hearing loss. Mr Parker did not see this as an exhaustive list, adding ‘radiotherapy’ and ‘smoking’ as supplementary causes.
Originally, the defendant’s medical expert asserted that the claimant did not have bulging in his left ear at 4 kHz. However, this was an assertion made in error, which he readily accepted when notified upon cross-examination. In spite of his arithmetic error, Mr Parker maintained the conclusion of his assessment, on the basis that the deepest point of the bulge was at 2 kHz. He considered it ‘alien’ and ‘inappropriate’ for a clinician to diagnose NIHL where the most affected frequency fell outside of the 3 to 6 kHz diagnostic range.
Diverging from Mr Yardley’s approach with Note 10, Mr Parker considered that a lower anchor point was more appropriate if the hearing threshold level was 5 dB better at 1 kHz after the adjustment for age-associated losses.
HHJ Gargan’s Findings
Firstly, the judge commented on the difference in anchor points chosen by each of the experts. He found Mr Parker’s method to be the correct approach. Since Note 10 specifically states that ‘Statistical data on AAHL are then consulted’, AAHL is to be considered after fixing the anchor points. Regardless, both experts still arrived at the conclusion that the most significant bulge was at 2 kHz.
Despite agreeing with Mr Yardley that the CLB Guidelines are not equivalent to ‘statute’, the judge reasoned that ‘a court should be reluctant to depart from them’.
On R3(a), the judge preferred Mr Parker’s approach. He stated that a ‘distinctive feature’ of a diagnostic audiogram is a notch between 3 and 6 kHz. It was agreed by both experts that notches could ‘spread or broaden’, but would ‘not normally’ extend to involve 2 kHz.
HHJ Gargan opined that:
‘Nothing in the CLB Guidelines suggests that the “spread” of the hearing loss from its principal point would result in the greatest loss being at the point of spread rather than at the point of the original notch’.
He went on to say that:
‘... such a development would be inconsistent with the point of the original notch representing the most vulnerable frequency to noise exposure in that individual. The frequencies to the side may increasingly “catch up” but if the hearing loss in the adjoining frequencies were to surpass the original notch, that would suggest either (i) there was some other process at work or (ii) for some unexplained reason the adjoining frequency had become more sensitive to noise than the point of the original damage. There is no support for such a process in the CLB Guidelines’.
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In respect of the Gates Paper, HHJ Gargan regarded this to be of ‘limited weight’ and of ‘limited assistance’, while also drawing on the claimant expert’s observation that deepest losses at 2 kHz are ‘atypical’.
As such, the Circuit judge found that a non-age factor created a bulge most prominent at 2 kHz and the claimant, on the balance of probabilities, could not show that his most affected/sensitive frequency fell within the range of 3 to 6 kHz. His hearing loss was therefore idiopathic and not attributable to noise exposure during the course of employment with the 2nd defendant. Both experts agreed that if hearing loss was found to be idiopathic, the claimant’s tinnitus would also be diagnosed as idiopathic.
The claim therefore failed on causation, as well as limitation, and judgment was entered for the 2nd defendant.
Feature: Investigations in Disease Claims: Feature 1 – NIHL Claims (BCDN Edition 244)
INTRODUCTION
This week, we introduce a new feature series, which focuses primarily on investigations conducted during the course of industrial disease claims.
In forthcoming editions of BC Disease News, we will provide separate schedules of investigations for each occupational disease, accompanied by general background information, specific to the relevant disease. Investigations are either conducted by Claims Inspectors (CI’s), or fee-earners themselves, over the course of a claim.
Typically, investigations and the taking of witness statements consider the genuine issues in dispute and ensure the efficient use of time and resources.
Accordingly, forthcoming editions will consider investigations into: 1. Noise-Induced Hearing Loss (NIHL) Claims (in this week’s edition); 2. Cumulative Back Claims; 3. Dermatitis Claims; 4. Asthma Claims; and 5. Work Related Upper Limb (WRULD) Claims:- o CTS; o Rotator Cuff Tendonitis & Shoulder Impingement; o Epicondylitis; o Stenosing Tenosynovitis; o De Quervain’s Disease.
Upon completion of our feature series, publication of our Investigations in Disease Claims Guide will follow.
GENERAL BACKGROUND TO NIHL CLAIMS
Noise is deemed as any unwanted/undesirable sound, arising from any vibrating source of energy. The 3 factors that determine the loudness of noise are proximity, frequency and intensity.
Proximity to the source of the noise is important to bear in mind when conducting investigations e.g. how close to the source would the Claimant have been situated?
Noise levels are measured using a conventional noise meter or dose-meter and are ‘A’ weighted. ‘A’ weighting is designed to reflect the response of the human ear to noise, at high and low frequencies, the human air is not very sensitive.
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Evidence provided by the Claimant is often subjective e.g. ‘I had to shout to the person next to me’. This is an example of a Claimant estimating how high the noise levels were by reference to needing to shout over a certain distance. Department for Employment’s 1972 Code of Practice – noise limits have been exceeded and should surveyed where ‘it was necessary to shout in order to be audible to a person about one meter distant’.
The 2005 Guidance (‘the Guidance’) provides the following table:
Importantly, noise levels and daily noise level dose are not the same thing. The daily noise level dose takes into account noise exposure throughout the Claimant’s working day. Lep,d is a worker’s daily exposure to noise at (normalised to an 8 hour day), taking into account the average levels of noise and the time spent in each area.
The table below shows the combinations of noise and exposure times required to give a ‘daily dose’ of 85 dB(A)Lep,d (8 hours).
Controlling noise/reducing the risks of noise is an important aspect of the insured’s duty. Such measures include: • Using quieter equipment or a different, quieter process; • Engineering/technical controls to reduce, at source, the noise produced by a machine or process e.g. a silencer, dampeners; • Using screens, barriers, enclosures and absorbent materials to reduce the noise on its path to the people exposed e.g. ‘hush huts’; • Designing and laying out the workplace to create quiet workstations; • Improved working techniques to reduce noise levels; • Limiting the time people spend in noisy areas; • Automation. • A low-noise purchasing policy for machinery and equipment; • Proper and regular maintenance of machinery and equipment that takes account of noise so it does not get louder over time. • Installation arrangements, e.g. methods of mounting and location, to ensure machinery operates as quietly as possible; and • How different ways of operating the machine affect the noise it produces.
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Different types of hearing protection provide varying strengths of attenuation. This must be taken into consideration and the attenuation value to be subtracted from the Lep,d value. Ear plugs range from 10–30 dB and ear muffs range from 20–30 dB. However, these are only valid when they are fitted properly and the equipment is in good working order. If the equipment is worn, there needs to be provision of new equipment and steps for the claimant to be able to obtain such.
Important to obtain information (if available) regarding the frequency of usage. If hearing protection is removed in noisy areas, even for short periods, the amount of protection provided will be severely limited.
As wear time is decreased from 100% of time exposed, the effective protection offered decreases. A significant reduction in protection is found even if the wear time is 90%. If the hearing protection is worn for 50% of time exposed, the attenuation offered is only about 3 dB.
Common Law
The first general regulations in the UK to protect employees’ hearing from exposure to loud noise were only introduced in 1990.149 Prior to this, common law negligence is relevant - did the reasonable employer, having positive thought for the safety of its employees, know, or ought to have known about the dangers associated with excessive noise? When did employers gain this knowledge of risk? What was considered to be dangerous noise exposure which would put employees at risk?
For many larger employers in the UK, 1963 is taken as the date when they knew, or ought to have known, that employees who were being exposed to a daily noise dose of 90 dB(A) LEP,d were at risk of potential hearing loss.
For small and medium-sized employers, this date may be too early; knowledge would only be acquired in April 1972 with the issue of a Department of Employment Code of Practice. Even then, employers would probably have 18 months-two years to implement hearing conservation measures. Therefore, the ‘actionable’ or ‘guilty’ date of knowledge for such employers is probably April 1974. This would be viewed as the constructive date of knowledge.
Exposures before 1963 or 1974 (dependent upon the relevant date of knowledge) would be ‘non-negligent exposure’ for which the employer cannot be liable because it could not foresee the risk of injury before this date.
Statutory Duties
The first generally applicable statutory duties were set out in the Noise at Work Regulations 1989, which came into force on 1 January 1990.
Employers’ duties are ‘triggered’ when certain ‘action levels’ are reached.
Under the 1989 Regulations the actions levels were as follows: • 1st Action Level: 85-89 LEP,d • 2nd Action Level: 90+ LEP,d • 3rd Action Level: ‘Peak Action Level’ – triggered if noise levels reach 140 dB irrespective of the exposure time.
1st Action Level o Carry out noise assessment to determine noise levels and employees’ daily noise dose. o The employer has to warn the employee that there is a risk to hearing from the noise exposure. o The employer should strongly recommend the wearing of hearing protection to conserve hearing. o If the employee elects to wear hearing protection, then the employer must provide proper and adequate protection and training on how to use it correctly and how to maintain and replace it. o The wearing of hearing protection is not mandatory.
149 Prior to this there was specific duties with respect to woodworking in the Woodworking Machines Regulations 1974.
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2nd Action Level o Reduce noise levels at source by engineering means or reducing exposure by changes to systems of work, or limiting the time spent in noisy areas. o If the above does not reduce exposure sufficiently, then provide and enforce the wearing of proper and adequate hearing protection - the mandatory wearing of protection must be supported by signage. o Provide training on how to correctly use the protection and maintain and replace it.
Table: Employer action required at the different action levels
The current Control of Noise at Work Regulations 2005 came into force on 6 April 2006 and reduced the action levels. The actions levels are now known as the Lower Exposure Action Value (LEAV) and the Upper Exposure Action Value (UEAV). The duties under the LEAV and the UEAV correspond with the 1st and 2nd Action Levels of the 1989 regulations, but each is now reduced by 5 dB: • LEAV: 80 dB(A) LEP,d • UEAV: 85 dB(A) LEP,d
There is also a new maximum exposure limit of 87 dB(A) LEP,d. This limit takes into account the reduction in noise by hearing protection. Taking into account the attenuating effects of the protection, then no-one should be exposed to daily noise exceeding this limit. A table showing a timeline of key dates relevant to breach of duty is shown below. Table: Timeline of key dates relevant to breach of duty
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TEMPLATE SCHEDULE OF INVESTIGATIONS IN A NIHL CLAIM
1. PRE-1974 EXPOSURES
Foreseeability in common law negligence may be an issue in respect of any pre-1974 exposures. Consider whether this could provide (i) a complete defence, or (ii) reduce the insurer’s share of the claim.
If foreseeability is in issue then evidence (documentary / lay) will be required looking at: i. Nature of employer’s business? ii. Industry in which operated? iii. Size of employer-sites, employees, turnover (any other measures)? iv. Resources of employer-any H & S and / or R & D and / or OH departments? v. Claimant’s job title and role description? vi. Periods of alleged exposure? vii. Nature of alleged exposure? a. Location within premises / site b. Sources (identify any departments, plant & equipment etc. where relevant) c. Proximity d. Frequency e. Duration f. How did plant / systems of work / exposures change over material period? viii. Likely noise exposures-Leq and / or Lep,d assessments? ix. Any complaints made about noise at material time? If so when, where, by whom, to whom, nature of same, response to these? x. Any specific knowledge in respect of noise and dangers associated with NIHL-if so what and when and by whom and how acquired? xi. Subjective assessments of noise exposure-see table below.150
2. PRE-01/01/1990 EXPOSURES
In addition to 1(i)-(x) above. i. Noise surveys conducted a. When b. What parts of business / processes / departments / plant & equipment c. By whom-competency and qualifications d. Results e. What happened post surveys? f. How, when and by whom were surveys / results of assessments periodically reviewed? g. If plant / processes changed were surveys / assessments repeated? ii. Hearing Conservation Programmes a. Nature of programme b. What parts of business / processes/departments / plant & equipment c. Engineering measures taken to reduce / control noise at source? i. When?
150 HSE Guidance on Control of Noise at Work Regulations, 2005.
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ii. What measures-silencers, noise dampeners, hush huts etc.? iii. What parts of business etc.? iv. By whom? v. Reduction achieved? d. Changes to systems of work to reduce / control exposures i. When? ii. What measures-job rotation, automation, substitution by quieter plant etc.? iii. What parts of business etc.? iv. By whom? v. Reduction achieved? e. Hearing Protection i. From when? ii. Enforced? How? What areas / processes / plant etc.? iii. If not enforced why not? Any issues of Con Neg? iv. What type of HP? o Make o Model o Attenuation o How, why, by whom was it selected as being suitable v. Who provided HP? f. Training & education i. Who provided training? What was their competency / qualifications to do so? ii. When was training provided and to whom? iii. How was it delivered? iv. What was content of training: o Did it provide information regarding noise exposure dose? o Risk to damage to hearing o Advice that HP must be worn-when and where o How to obtain HP? o How to wear HP? o How to maintain HP and identify & report faults / defects in it? o How to replace the HP g. Health Surveillance Programme i. When ii. Nature iii. Who iv. Competency and qualifications v. Results reported to employees? Actions taken? h. Complaints / previous claims? i. Any complaints made by employees in respect of noise / hearing damage etc. i. When? ii. To whom? iii. From whom? iv. Nature of complaint? v. Response to complaint? vi. Any previous NIHL personal injury claims-details & outcomes? j. Other i. Any HSE investigations / communications regarding noise? ii. Nature / Outcomes? iii. When, what part of plant / processes? iv. Background information on claimant o Previous employments o Previous noisy employments o Social / recreational exposures o Previous NIHL claims o Member of armed forces / shooting history o Member of trade union(s)
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o Other of relevance 3. 01/01/1990 – 05/04/2006 EXPOSURES
i. As 1 & 2 above ii. Consider whether claimant’s exposure above 1st or 2nd action level? iii. How were the results of the noise exposure assessment (and risks of NIHL) communicated to employees? a. By whom? b. To whom? c. When? d. Nature of communication? iv. Were Ear Protection zones identified and demarcated within premises by signage? Full details. v. How was need for wearing of HP within such zones communicated and enforced?
4. POST-05/04/2006 EXPOSURES
i. As 1, 2 & 3 above. ii. Medical Health Surveillance a. What is the programme? b. Why implemented and from when and how often? c. Competency and qualifications of persons conducting programme? d. Has C / other employees been identified with noise damage? Details including when / what noise exposure it relates to? e. Were results communicated to C? i. When ii. By whom iii. Nature / gist of communication? iv. Was C referred to doctor or any specialist as a result? When & outcome? v. What action taken and when (i.e. C removed from noise? f. Any analysis of anonymised health results made? When, by whom, to whom, what did / does it show, actions taken?
5. LIMITATION
Where limitation is in issue you will need evidence dealing with s.33 of the LA 1980 and how any delay has caused deterioration in evidence, prejudice to defendant and why a fair trial is no longer possible. This may include: i. Changes in employer name, status, ownership including when? ii. Changes in premises and when? iii. Changes in plant and equipment and machinery and when? iv. Changes in systems of work and when? v. Changes in management structures and personnel? vi. Lay witness recollection-or lack of it-on all the issues 1-4 above, but broadly: a. Claimant’s role and likely noise exposure? b. Noise control measures? c. Hearing conservation measures? vii. Availability of lay witnesses a. What evidence can they provide? What can’t they comment on? How has recollection of events been affected? b. What lay witnesses no longer available? i. Why? ii. What has happened to them / where are they? iii. From when? iv. What would they have provided evidence on? viii. What documents exist? What is their relevance? ix. What documents did exist but are no longer available? a. Why? b. When lost or destroyed?
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c. What did they show? x. Previous NIHL claims history a. Claims by whom b. In respect of what exposures, sources, periods-any relevance to C’s claim? c. Solicitor / trade union representations? d. Outcomes? e. Insurers / brokers involved?
Documents
This Checklist is intended only to be a guide and it is not exhaustive. NB: IN CASES WHERE SUCH DOCUMENTS ARE NOT AVAILABLE IT IS VITAL TO CLARIFY WHETHER (I) THEY NEVER EXISTED, OR (II) IF THEY DID WHAT BECAME OF THEM AND WHEN?
The Injury
1. Any relevant complaints made (if at all). 2. Any HSE investigations or correspondence in relation to this claim, any other similar incidents or the system of work in general. 3. Any internal investigation reports or forms, including any statements taken or memos sent. 4. Any documents completed for the purposes of the DSS. 5. Documents relating to any other similar claims.
Noise Assessments/Surveys & Health & Safety Records
1. Health & Safety Committee Meeting Minutes dealing with noise awareness and any hearing conservation policy. 2. The Company’s Health & Safety Policy — particularly in relation to noise and hearing protection / conservation. 3. Any specific noise reduction or noise conservation policy or policy statement. 4. Any other relevant internal health and safety documents, including memos and e-mails, relating to noise. 5. Noise assessments / surveys / noise level readings and / or any relevant risk assessments — throughout the duration of the Claimant’s employment. 6. Documents showing any other sources of information obtained, such as: a. independent health & safety reports commissioned; work surveys; b. documents obtained from HSE, trade associations, health & safety industry journals.
Noise Control Measures
1. Schematic plan of premises and plant & equipment. 2. Identity of plant, machinery, equipment-manufacturer name and model numbers. 3. Any manufacturers’ information provided in respect of machinery / plant / equipment noise levels. 4. Programme of maintenance and repair. 5. Documents illustrating any steps taken to reduce noise exposure (e.g. by engineering means or changes to the system of work).
Hearing Protection
1. Manufacturers’ / suppliers’ product information (e.g. catalogues, marketing information etc.) for all ear protection provided, including the name and make. 2. Any manuals in respect of the use of the ear protection. 3. Purchase records to show how often and how many items are typically purchased (e.g. each month). 4. Documents showing what ear protection the Claimant received and when (e.g. signed receipt forms). 5. Documents relating to suitability (e.g. trials, discussions with suppliers etc.).
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Training & Enforcement
1. Health & Safety Handbook / Manual — preferably the copy signed and dated by the Claimant to acknowledge receipt. 2. Documents showing all training, instructions and warnings given to the Claimant regarding the dangers of noise and how to protect hearing, including: a. certificates; b. course notes; c. course registers d. internal memos; e. publicly displayed warning notices around the factory — provide photographs if possible; f. handbooks/booklets; g. notes of guidance and any other literature etc. 3. The Claimant’s Training Records for all aspects of their work and, in particular, in respect of noise awareness. 4. Documents relating to enforcement procedures, including warnings given and disciplinary procedures taken against employees (particularly the Claimant) for failure to wear ear protection.
Health Surveillance
1. Documents detailing any system of health surveillance: a. What is the programme? b. Why implemented and from when and how often? c. Competency and qualifications of persons conducting programme? d. Has C / other employees been identified with noise damage? Details including when / what noise exposure it relates to? e. Were results communicated to C? i. When ii. By whom iii. Nature / gist of communication? iv. Was C referred to doctor or any specialist as a result? When & outcome? v. What action taken and when (i.e. C removed from noise? f. Any analysis of anonymised health results made? When, by whom, to whom, what did / does it show, actions taken?
Complaints or Comments & Action Taken
1. Documents relating to any written or oral complaints or comments made by the Claimant or any other employees about the symptoms or the system(s) of work. 2. Documents detailing the Company’s response to any such complaints or comments and what action was taken, if any. 3. All correspondence passing between the Company and the Health & Safety Executive regarding this incident or any other similar matters.
Trade Union
1. Is / was there a Union in existence? Has noise ever been raised as an issue? If so, provide details of any action taken by the Union and / or copies of any correspondence with it and / or minutes of any meetings with its representative(s).
The Claimant
1. Contract of employments 2. Job roles / descriptions 3. Note: Personnel & Occupational health records will be obtained by BC Legal direct.
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Inspection of Workplace / Preserving Evidence
May be relevant in respect of recent exposure claims where plant / machinery being shut down or replaced or premises closing down. Please identify this within the report so that prompt action can be taken to inspect the workplace and preserve any evidence.
Using 6 kHz as an Anchor Point: Percy v Northern Gas Networks & 2 Ors. (Newcastle County Court, 15 June 2018) (BCDN Edition 245)
Case judgment has recently been handed down in Percy v Northern Gas Networks & 2 Ors. (Newcastle County Court, 15 June 2018). His Honour Judge Freedman ruled on the correct interpretation of the Coles Guidelines, in respect of bulge analysis, for the purpose of ensuring correct diagnosis of NIHL.
The 73 year-old claimant alleged that he had been exposed to excessive noise during his employment with all 3 defendants. However, the claim against the 2nd defendant was dismissed.
In his employment with the 1st defendant, between 1979 and 1987, he worked as a fitter. In his employment with the 3rd defendant, at various times during the 1980’s and 1990’s, he worked as a shot blaster.
The 1st and 3rd defendants conceded breach of duty.
Instructed engineer, Mr Worthington, found that it was ‘highly likely that the daily noise exposure level was well in excess of 90 dB(A) LEP,d during his employment with the 1st and 3rd defendants’.
In respect of medical evidence, Mr Parker was instructed for the defendants, while Mr Johnson was instructed on behalf of the claimant. The claimant’s hearing was represented on 2 audiograms, one produced in 2013 and another, produced in 2015.
According to the 2013 audiogram, the claimant’s mean bilateral hearing threshold level (HTL) across 1-3 kHz was 33.6 dB. Over the same frequency range, according to the 2015 audiogram, hearing losses were calculated as 42.0 dB. His hearing loss was significant and he had mild tinnitus.
Although R1 and R2 of the CLB Guidelines were satisfied in both audiograms, the medical experts were in disagreement over the correct anchor points to use when undertaking bulge analysis of audiograms, i.e. compliance with R3(a).
Paragraphs 7.1 and 7.2 of the CLB Guidelines state that for R3(a) to be satisfied:
‘Evidence of probable presence of NIHL is considered to be present if there is a downward notch in the audiogram in the 3-6 kHz range that is large enough to be identifiable with a degree of confidence ... Evidence for NIHL is also provided on the audiogram by sufficiently large relative bulge downwards and to the left in the 3-6 kHz range… in a considerable portion of NIHL cases, especially after the age of about 50 years, the characteristic high frequency notch is missing. This is usually due to the additional presence of high frequency impairment of other causation … Typically, that has the effect of converting a noise-induced audiometric notch into a bulge … In other cases it may reduce the notch to a size (e.g. 5 dB) that is not significant as a notch. Nevertheless, it will add to the size of a potential bulge and should be examined closely to see if it classifies as a bulge…’
When calculating notching / bulging, upper and lower anchor points are used.
If the claimant’s expert was deemed to have used the appropriate anchor points, bulges in both audiograms were ‘Coles-compliant’. If, however, the defendant expert’s different anchor points were more suitable, they were not ‘Coles-compliant’.
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The Anchor Point Issue
Generally, 8 kHz is used as the upper anchor point when calculating the size of notches/bulges. There are, however, certain circumstances when 6 kHz is the legitimate upper anchor point.
Initially, Mr Johnson used the 8 kHz anchor point in his analysis of bulging in the 2013 audiogram.
In the 2013 audiogram, the claimant’s HTL at 8 kHz was 85 dB. Whereas, in the 2015 audiogram, no HTL could be recorded (inferring maximum HTL of 100 dB tested).
After having reviewed the 2015 audiogram, he revisited his calculations and proceeded to use 6 kHz as the upper anchor point. His change of mind was provoked by the ‘precipitous drop-off’ of more than 15 dB at 8 kHz between the original audiogram and the later audiogram. Mr Johnson also observed a 21 dB difference between 6 and 8 kHz on the 2013 audiogram, where the expected AAHL (50th percentile) was 9 dB.
Altered anchor points for avoidance of Coles calculation distortion yielded a ‘Coles-compliant’ bulge in the 2013 audiogram.
While Mr Parker accepted that bulges could be discerned using a 6 kHz upper anchor point, he saw no justification, in this instance, for departing from the standard approach, i.e. the use of 8 kHz as the upper anchor point could still provide a reliable interpretation. He also argued that the CLB Guidelines does not advocate comparison between audiograms to diagnose NIHL.
Counsel for the claimant argued that it was ‘illogical to ignore the second, later audiogram, particularly where there is already evidence of disproportionate high-frequency losses’. To do so would constitute a failure ‘to accord proper weight to the significant changes which occurred between 2013 and 2015’.
HHJ Freedman concluded, on his interpretation of Note 10, that:
‘… in relation to the ‘precipitous drop-off’ point … it is not being contemplated that 6 kHz can be used to assess whether there is a bulge in 2013, when there has been diminution in values at 8 kHz over the ensuing two years’.
The judge went on to conclude that ‘exceptional’ disparity between HTL’s at 6 and 8 kHz could justify a departure from an 8 kHz anchor point. Using the 25th percentile, the difference between AAHL and actual loss was 13 dB and even though this was deemed to be ‘significant’, it was not enough to depart from the usual anchor point.
A key factor of the judge’s ratio on this issue was that the claimant’s expert shifted his opinion retrospectively, despite feeling able to interpret the 2013 audiogram using 8 kHz as the upper anchor point at the time. In any event, the CLB Guidelines do not explicitly refer to comparisons of audiograms produced at different times.
Mr Parker was therefore right to use 8 kHz as the upper anchor point.
Having ascertained the correct methodology for calculating bulges/notches, it was necessary to consider whether ‘Coles-compliant’ bulges were present.
The Bulge Calculation Issue
Under paragraph 7.6 of the CLB Guidelines, it states that:
‘A high-frequency bulge in the air conduction audiogram that is sufficiently large to be indicative of the probable presence of NIHL is defined as follows. Such a bulge is present if the HTL at 3 and/or 4 and/or 6 kHz, after any due correction for earphone type…is at least 10 dB greater relative to the comparison values for age-related hearing loss at corresponding frequencies. If an average of two or more HTL measurements can be used, the 10dB figure may be slightly reduced… Occasionally, the bulge extends to involve 2 kHz or even 1 kHz’.
Mr Johnson argued that there was a ‘Coles-compliant’ bulge, irrespective of Mr Parker’s preferred anchor point analysis, as the bulge at 4 kHz was at least 10 dB greater than those at 3 or 6 kHz. Although ‘notching’ at 4 kHz did
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not meet the 10 dB criterion, he maintained that ‘it was appropriate to look at comparative values as opposed to absolute values’. There was a recovery on both sides (3 and 6 kHz) of the calculated bulge values at 4 kHz, which he argued was all that mattered.
Claimant counsel submitted that the identification of a notch requires the comparison of HTL’s with ‘adjacent thresholds’ and that the same should apply to bulge calculations.
The defendants’ expert contested this assertion, stating that recoveries at ‘adjacent thresholds’ are only relevant if there is a notch and not if there is a bulge.
HHJ Freedman, again, preferred the analysis of Mr Parker, reasoning, at paragraph 31:
‘… it is clear that to determine the presence or otherwise of a bulge, hearing threshold levels should be compared “relative” to the comparison values for age-related hearing loss at corresponding frequencies. As Mr Cooper points out, this does not suggest a comparison with adjacent frequencies in the bulge line, in the manner undertaken by Mr Johnson. The Guidelines are comparing the claimant’s hearing threshold levels with his predicted age hearing loss to determine if there is a difference of at least 10db at the frequencies which are usually affected by noise’.
As such, ‘corresponding frequencies’ does not equate to ‘adjacent frequencies’. If this was intended by the CLB Guidelines, then it would have been ‘overtly stated’.
When asked, Mr Parker answered that he was unaware of any other expert carrying out a bulge analysis in the way that Mr Johnson purported and HHJ Freedman remarked that he was struck by Mr Johnson’s unsatisfactory response to the same question.
‘In short, the guidance which has been given is that if there is no notch, it is necessary to see if it has been ‘converted’ into a bulge. In other words, it is only if there is no notch that it is then necessary to undertake a bulge analysis ... to determine the presence or otherwise of a bulge, hearing threshold levels should be compared “relative” to the comparison values for age-related hearing loss at corresponding frequencies ... this does not suggest a comparison with adjacent frequencies in the bulge line ... The Guidelines are comparing the claimant’s hearing threshold levels with his predicted age hearing loss to determine if there is a difference of at least 10db at the frequencies which are usually affected by noise’.
Accordingly, it was HHJ Freedman’s view that Mr Parker’s approach reflected the correct interpretation and application of the Guidelines.
Conclusion
On the balance of probabilities, NIHL was not established and the claim against the 1st and 3rd defendants was dismissed.
A factor of potential influence, during the course of the trial, was that oral expert evidence was concurrently adduced, otherwise known as expert ‘hot tubbing’.
We previously reported, in edition 211 of BC Disease News (here), that the Civil Procedure Rule Committee (CPRC) had amended Practice Direction 35 to permit the court to direct ‘experts from like disciplines to give their evidence and be cross - examined on an issue - by - issue basis, so that each party calls its expert or experts to give evidence in relation to a particular issue, followed by the other parties calling their expert or experts to give evidence in relation to that issue …’
Through ‘hot-tubbing’, if an expert is more convincing, it is arguably more visible than if witnesses are questioned on a traditional basis.
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Double Compensation and an Application for Strike Out and QOCS Disapplication: Smith v Baird Clothing Menswear Limited & Ors (2018) (BCDN Edition 245)
BC Legal has recently been successful in removing QOCS protection in a (NIHL) claim where the Claimant sought damages for injuries which had already been compensated 7 years prior to service of the Claim Form.
The Claimant’s Solicitors were instructed in 2015. In 2017, proceedings were served on the Defendants, along with the Letter of Claim. In the Particulars of Claim, medical report and Part 18 responses, the Claimant claimed to have only attributed her hearing loss to excessive occupational noise exposure in 2015.
Although the insurers on risk for the Defendants were unaware of the claim at the pre-litigation stage, once the proceedings were received, their records showed that the Claimant had pursued an identical claim, in 2010, against 2 of the 4 Defendants to the present claim.
What is more, even though details of the earlier claim were missing from the Claimant’s medical records, archived claim documents revealed that the Claimant had undergone a medical examination and hearing test in 2010 and the Claimant’s date of knowledge was traced back to 2005.
It was confirmed by the 2010/2011 claim documents and the Solicitors that dealt with her initial claim in 2011, that the Claimant received a costs inclusive settlement of £6,000, in respect of her earlier claim. The Solicitors that dealt with the initial claim advised the Claimant’s newly instructed Solicitors that the Claimant had received £1,350 in compensation, out of a £6,000 all-inclusive settlement. The Claimant later denied receiving compensation, but this was irrelevant, as evidence of her earlier claim and her dishonesty was exhibited in court documents.
In January of 2018, BC Legal, instructed by the 2nd Defendant, made an application on behalf of all 4 Defendants, seeking: 1. That the Claimant’s claim against all the Defendants be struck out subject to CPR 3.4(2)(b) as the proceedings are an abuse of process and further due to the Claimant’s dishonesty. 2. The Claimant do pay the Defendants’ costs of and occasioned by this application. 3. The Claimant do pay all of each Defendants’ costs of the entire claim. 4. That Qualified One Way Costs Shifting be disapplied in this matter under CPR 44.15(b) that the proceedings are an abuse of the Court’s process and further under CPR 44.15(c)(i) due to the conduct of [the] Claimant.
At 3.30pm on 19 April 2018, the day before the application hearing, the Claimant filed a Notice of Discontinuance. In witness statements filed that same afternoon, the Claimant stated that she had ‘forgotten about the earlier claim’ when she completed the Part 18 replies and signed the Particulars of Claim. It was clear that the Claimant’s Solicitors had no knowledge of the earlier claim until the application was made, as they directly questioned the Claimant on this issue and she denied bringing a claim in the past.
On the day of the hearing, the Defendants made a joint application to adjourn the hearing and stated their intention to make a further application to set aside the Notice of Discontinuance and continue with the original application to strike out the claim and recover costs. The matter was adjourned to a further hearing, on 25 June 2018, wherein the Claimant was ordered to personally attend and give oral evidence. The costs position was reserved with the court, specifically to consider whether a wasted costs order should be applied to the costs of the hearing, on 20 April 2018.
Following the hearing, the Claimant personally made an offer to the Defendants of £10,000 for their costs incurred to-date, in an attempt to avoid having to attend the later hearing, in June of 2018. However, 24 hours after the offer was made, it was inexplicably withdrawn. No further offers were made before the relisted hearing, on 25 June 2018.
In the interim, the court ordered the Claimant’s Solicitors to file a witness statement confirming what steps had been taken in the 3 month period between the filing of the Defendants’ application and the Claimant’s Notice of Discontinuance being filed; why this was left until the day before the hearing? The ensuing statement revealed that
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only 1 letter had been sent and 1 phone call had been made, prior to April 2018. The Claimant denied receiving the letter.
On 25 June 2018, the adjourned strike out hearing was scheduled to take place. Upon arrival at the court, the Claimant reinstated her £10,000 offer to circumvent the hearing, but this was not accepted. In response, the Claimant made an increased offer of £13,000. This was accepted by the Defendants, on the proviso that the order specifically stated that the costs order was enforceable and that the Claimant had no QOCS protection. The desired order was subsequently approved by the Judge.
As such, there was no specific finding of abuse of process or dishonesty, which was sought in the original application. However, the costs order agreed at the hearing made specific reference to its enforcement and also referred to the claimant’s inability to benefit from QOCS protection. Given that the Claimant is now personally liable for £13,000 of costs, arising out of a claim which yielded £1,350 in damages in 2011, the outcome in Smith should serve as a deterrent to the Claimant bringing more spurious claims in future.
12% Increase in Canadian Worker NIHL Cases as Hearing Protection Uptake Increases (BCDN Edition 245)
In a Canadian study of the oil and gas drilling sector in the state of British Columbia, signs of NIHL in workers increased by 12% between 2012 and 2017.151 This upward trend appears to contradict data on the use of foam earplug hearing protection, which increased by 4% (to 98%) in the same 5-year period.
In 2012, NIHL symptoms were recorded in 33% of employee hearing tests, increasing to 45% in 2017. This equated to 294 employees, of which 65% (194) were under the age of 35.
WorkSafeBC occupational audiologist, Sasha Brown, has warned that employers will not prevent the risk of NIHL onset in its staff simply by supplying hearing protection and ensuring that it is worn:
‘The ear plugs or ear muffs might be the wrong size, inserted or worn incorrectly, not worn for long enough, or they may not be providing enough protection for the duration and intensity of noise exposure’.
According to the Control of Noise at Work Regulations 2005, which came into force on 6 April 2006, if Lower Exposure Action Value (LEAV) [80 dB(A) Lep,d] is reached, employers are under a duty to strongly recommend the wearing of hearing protection to conserve hearing, but the wearing of hearing protection is optional. However, if the employee wears hearing protection, the employer has to provide proper and adequate protection and training on how to use it correctly, maintain and replace it.
If the Upper Exposure Action Value (UEAV) [85 dB(A) Lep’d] is reached, employers must provide and enforce the wearing of proper and adequate hearing protection, supported by signage. Further, training on how to correctly use, maintain and replace protection, must be provided.
The LEAV and UEAV replaced the 1st (85-89 Lep,d) and 2nd (90+ Lep,d) Action Levels. These were founded in the Noise at Work Regulations 1989, which came into force on 1 January 1990.
It is clear from this research, therefore, that while employers may have improved their enforcement of hearing protection in the workplace, they may not be simultaneously checking that hearing protection is properly fitted and effective.
This is necessary, if an employer wishes to rely on a breach of duty defence to a NIHL claim.
151 ‘Hearing-test data reveals steady rise in hearing loss among oil and gas drilling workers’ (22 August 2018 WorkSafe BC)
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How Do Cognitive and Auditory Factors Affect the Perception of Speech in Background Noise? (BCDN Edition 248)
A new study has investigated whether cognitive and auditory factors affect the ability of a listener to hear in background noise.152
Although many patients with elevated pure tone thresholds report difficulty with distinguishing speech in background noise, it is not unusual for someone with standard pure tone thresholds to report the same difficulty.
It can therefore be implied that there must be factors which contribute towards a person’s ability to hear speech in noise other than hearing loss caused by a loss of cochlear hair cells. In other words, there must be factors outside of audiometry detection, which contribute towards a person’s ability to hear speech in noise.
One potential factor is ‘hidden hearing loss’. This occurs when synapses in the ear are damaged. This does not impair a listener’s ability to hear pure tones, but does cause a listener to have difficulty when distinguishing speech in noise. We have previously discussed hidden hearing loss in editions 113 (here) and 184 (here) of BC Disease News.
The New Study
122 adults with normal, or near-normal hearing, participated in the new study. After undertaking tasks which assessed their ability to hear speech in noise, the participants were each given a composite speech-in-noise score (CSS). The researchers identified the 30 best performing participants and compared their hearing thresholds, temporal perception, noise exposure, attention and working memory against the 30 worst performing participants.
Analysis showed that working memory scores and extended high-frequency (EHF) (above 8 kHz) thresholds were significantly different between the two groups. The EHF hearing levels and working memory scores were responsible for 41% of the variations in CSS scores. Moreover, working memory scores and EHF thresholds were able to correctly predict low CSS with ‘reasonable’ (76%) accuracy.
Study Findings
For listeners with normal audiometry, this study insinuates that their ability to hear speech in noise is influenced by EHF hearing loss and working memory.
If working memory is related to the ability to hear speech in noise, this may explain why some patients with normal hearing report difficulties.
Similarly, a claimant may produce normal audiogram but also have elevated EHF thresholds, which are not routinely included in audiometric testing.
As a result, the study authors recommend that audiologists examine the working memory and EHF thresholds of patients who report difficulty with hearing speech in noise. Further, they advise that:
‘For those who have a history of noise exposure, clinicians could point out that poor EHF thresholds are often associated with noise exposure and focus on the importance of avoiding excessive noise exposure, or using hearing protection when avoidance is not possible’.
It must be noted that this study is not without its limitations. For example, participants in the worst CSS group did not necessarily find it difficult to hear speech in noise. They were simply the least able. Age may also have adversely impacted the low performing group, which was, on average, 6.1 years older than the high performing group.
152 Yeend, I., Beach, E. F. & Sharma, M. Working Memory and Extended High-Frequency Hearing in Adults: Diagnostic Predictors of Speech-in-Noise Perception. Ear Hear (2018). doi:10.1097/AUD.0000000000000640 https://europepmc.org/abstract/med/30052557 (Accessed 17 September 2018)
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EHF Thresholds and Speech in Noise
The authors in the latest study base their assertion that “poor EHF thresholds are often associated with noise exposure” on two studies.
The 1st study was authored by Charles Liberman, who was also co-author of the ‘hidden hearing loss’ hypothesis.153 Here, college students, with normal hearing thresholds up to 8 kHz, were split into two groups. One group was regularly exposed to loud noise and the other group was not. Subsequently, the participants’ hearing was tested between 8 kHz and 16 kHz. Those at risk of noise damage exhibited greater hearing loss in this region. Findings were consistent with animal studies, which demonstrate that the first frequencies to be affected by noise are the highest that the species can hear.
The 2nd study, authored by Garreth Prendergast, found that noise exposure was associated with elevated thresholds at 16 kHz in females.154 As was also the case with the Liberman study, participants who had been exposed to noise were more likely to have elevated thresholds at 16 kHz, despite all participants having similar hearing at 8 kHz and below.
Working Memory and Speech in Noise
The mechanism of working memory creates temporary storage and allows the brain to manipulate the necessary information for completing complex tasks, e.g. language comprehension, learning and reasoning.155 A 2014 study found that both older and younger listeners with poor working memory were less able to distinguish speech in background noise, regardless of their age.156 Working memory does not appear to be affected by noise exposure.
Hidden Hearing Loss and Speech in Noise
The same research group that produced the new paper also published two published papers on ‘hidden hearing loss’ in humans. In both papers, they reported no link, or no significant relationship, between lifetime exposure to noise and ability to hear speech in noise.157 158
In the 2nd paper, the researchers concluded that that synapse damage is, at most, one of several factors that play a role in humans’ speech in noise performance.
Conclusion
The latest paper concludes that both auditory (function of the ear) and cognitive (function of the brain) factors may contribute towards speech in noise issues in listeners with normal audiograms.
If future studies find that working memory is involved with the detection of speech in noise, then this could provide an additional defence against a claimant who has minimal hearing loss at noise sensitive frequencies, yet alleges an inability to distinguish speech.
153 Liberman, M. C., Epstein, M. J., Cleveland, S. S., Wang, H. & Maison, S. F. Toward a Differential Diagnosis of Hidden Hearing Loss in Humans. PLOS ONE 11, e0162726 (2016). https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0162726 (Accessed 19 September 2018) 154 Prendergast, G. et al. Effects of noise exposure on young adults with normal audiograms I: Electrophysiology. Hearing Research 344, 68–81 (2017). https://www.sciencedirect.com/science/article/pii/S0378595516303203 (Accessed 19 September 2018) 155 Baddeley, A. Working memory. Science 255, 556–559 (1992). http://science.sciencemag.org/content/255/5044/556 (Accessed 19 September 2018) 156 Gordon-Salant, S. & Cole, S. S. Effects of Age and Working Memory Capacity on Speech Recognition Performance in Noise Among Listeners With Normal Hearing. Ear Hear 37, 593–602 (2016). https://www.ncbi.nlm.nih.gov/pubmed/27232071 (Accessed 20 September 2018) 157 Yeend, I., Beach, E. F., Sharma, M. & Dillon, H. The effects of noise exposure and musical training on suprathreshold auditory processing and speech perception in noise. Hearing Research 353, 224–236 (2017). https://www.sciencedirect.com/science/article/pii/S0378595517300710 (Accessed 20 September 2018) 158 Valderrama, J. T. et al. Effects of lifetime noise exposure on the middle-age human auditory brainstem response, tinnitus and speech-in-noise intelligibility. Hearing Research 365, 36–48 (2018). https://www.sciencedirect.com/science/article/pii/S0378595517306287 (Accessed 20 September 2018)
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Conversely, if a common view develops that there is a link between noise exposure, EHF hearing loss and speech in noise detection, claimants may begin producing audiograms that show hearing loss at higher frequencies as proof of causative noise-induced losses.
More De Minimis Success in NIHL Claims: Wiseman v Overhead Doors (GB) Limited (2018) (BCDN Edition 249)
In the recent cases of Harte and Nicholls, reported in editions 240 (here) and 241 (here) of BC Disease News, defendants have been successful in running de minimis non curat lex as a defence in noise-induced hearing loss (NIHL) claims. This has rebutted the presumption that after judgment in Dryden v Johnson Matthey [2018] UKSC 18 was handed down, any measure of NIHL would constitute an ‘actionable’ injury.
A common thread in these cases has been the preferential treatment of the LCB Guidelines (2015) over the CLB Guidelines (2000), when calculating noise induced losses across 1, 2 and 3 kHz. In this article, we report on the case of Wiseman v Overhead Doors (GB) Limited (2018), another case involving minimal noise induced losses, which was heard at Manchester County Court, in June 2018.
THE CLAIM
The claimant, a former sheet metal worker, alleged that he had developed noise-induced hearing loss as a result of historic employment with 3 defendants, from 1977 to 1988. The work that the claimant was engaged in was the same in each of the defendant’s premises. The claimant worked 8 hour days, 4 days per week, and ‘occasionally’ worked overtime.
In a witness statement, dated 4 September 2014, the claimant identified guillotines, fly presses, orbital grinders and hammers as being ‘constant’ and ‘continuous’ sources of noise exposure, causing him to have to ‘shout’ to communicate with co-workers. In the 2nd and 3rd defendants’ premises, there were 150 employees, all conducting the same work. Responding to Part 18 questions, the claimant identified jigsaws, circular saws, air powered drills and metal folding machines as further sources of noise exposure.
The defendants conceded limitation pre-trial, leaving breach of duty and causation in dispute.
Engineering Evidence
The single joint expert engineer, Mr Tudor, produced a report in July 2017. In calculating the noise levels to which the claimant was exposed, Mr Tudor was drawn to rely on Health and Safety Executive (HSE) documentation on noise in fabrication workshops, as the claimant had failed to provide ‘details regarding how close to the tools he was located, or how long each day he would use each tool’.
According to HSE, a noise level of 99 dB(A) would require a person to shout to communicate with a person 1.2m away, while a noise level of 93 dB(A) would require a person to speak very loudly to communicate with a person 1.2m away.
Taking into account the claimant’s overtime, the single joint engineer considered that the claimant’s daily noise dose would have been between 86 and 96 dB(A) Lep,d.
Mr Tudor went on to state that over ear muffs, provided by the employer, would have significantly reduced noise attenuation by between 25 and 30 dB. The claimant’s evidence alleged that ‘he only wore it, effectively, when he was hammering’. If the claimant wore hearing protection, as alleged, it was Mr Tudor’s opinion that the claimant’s noise exposure would have been reduced ‘to below injurious levels’. It was not possible to say whether the claimant had been exposed to noise levels above the 1972 Code of Practice for Reducing the Exposure of Employed Persons to Noise guidelines on a day-to-day basis. The 1972 Code of Practice recommended a maximum daily noise dose of 90 dB(A) Lep,d.
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THE TRIAL
The trial was heard before His Honour Judge Platts, at Manchester County Court, on 20 June 2018.
Breach of Duty
Firstly, on breach of duty, the judge considered the relevance of the claimant’s unchallenged assertion that he had to ‘shout’. Although the definition of shouting is ‘imprecise’ and ‘subjective’, the judge reasoned that both ‘shouting’ and ‘very loud talking’ would imply that the 1972 Code of Practice guidelines would have been breached.
Secondly, HHJ Platts considered the relevance of the date when the 2nd and 3rd defendants provided the claimant with ear muffs. He reasoned that it was ‘probably from 1985 onwards’ and identified that:
‘... the fact that the ear muffs were provided tends to suggest that those Defendants thought that noise levels were such that ear protection should be provided to their employees, even though they did not necessarily enforce the wearing of them’.
In light of all of the evidence on breach, HHJ Platts concluded, at paragraph 20, that:
‘... the noise levels did exceed the guidelines when the machines were being used and, on the Claimant’s unchallenged evidence, that noise was described as either continuous or constant. I accept his evidence that he had to shout and that puts the noise level in excess of the guidelines of 1972. I find that that was the case for both the first Defendants and the second and third Defendants and I therefore find that they were all in breach of duty’.
Causation
On causation, the judge considered R2(a) to be the only CLB Guidelines requirement in issue, namely that the claimant’s cumulative noise immission level (NIL) was in excess of 100 dB(A). The claimant produced 4 audiograms, all of which were consistent with NIHL.
The single joint engineer’s report noted that the claimant’s NIL would have been between 95 and 105 dB(A). On the balance of probabilities, HHJ Platts found that the claimant had proved that the overall exposure was in excess of 100 dB(A) NIL. Accordingly, causation was made out against all three defendants.
De Minimis
Subsequently, the judge considered the extent of the claimant’s NIHL, which was contested by all three defendants. Expert medical reports were provided by Mr Hasan, instructed on behalf of the claimant, and Professor Lutman, for the defendant.
Both experts were in agreement that the claimant’s total binaural hearing loss was the average of all 4 audiograms produced. Across 1, 2 and 3 kHz, Mr Hasan and Professor Lutman assessed the claimant’s hearing loss at 26.8 dB and 27.5 dB, respectively.
However, the experts disagreed over the proportion of hearing loss attributable to noise exposure. Mr Hasan, in his 2012 report, calculated the claimant’s age associated hearing loss (AAHL) at 8.3 dB, using the 50th percentile of ISO 7029. Therefore, he concluded that the claimant’s NIHL was as high as 18.5 dB.
Unlike Mr Hasan, Professor Lutman, who produced his medical report in 2017, was able to rely on the approach taken in the LCB Guidelines, which he had co-written. The latest guidance produced much higher age associated losses. With an AAHL of 24.3 dB, the claimant’s binaural NIHL was calculated at just 3.2 dB. In his report, Professor Lutman considered that such hearing loss was ‘too small to be noticeable’.
In the medical experts’ joint statement, Mr Hasan accepted that the analysis and methodology of Professor’s Lutman’s calculations would have produced 3.2 dB NIHL. Adopting his own, revised methodology and using the 25th percentile of ISO 7029, Mr Hasan arrived at a NIHL element of 5.5 dB. The claimant’s instructed expert did,
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however, under cross-examination, admit that the claimant’s NIHL would be ‘close to zero’ if he fell within the 5th percentile of AAHL and accepted that 3.2 dB NIHL would be ‘negligible’.
For this reason, HHJ Platts found that Mr Hasan’s calculation of 5.5 dB NIHL could not stand, preferring Professor Lutman’s superior analysis:
‘... the hearing loss, averaged out at 1, 2 and 3 kHz is 3.2 dB and that is the hearing loss which I find that the claimant has suffered as a result of the defendants’ breach of duty’.
The claimant also had a deficit at 4 kHz and sought to rely on the Moore Papers, in addition to the medical reports and joint statement, which discuss the perceptual effects of hearing loss for frequencies above 3 kHz. However, HHJ Platts disallowed the claimant’s application, on the basis that: 1. Mr Hassan’s written opinion, at the outset of trial, did not state that the Papers should form part of the consideration of the case; 2. It was too late to introduce the Papers as a new element at trial; and 3. The claimant had not included the Papers in the 6 months prior to trial when evidence should have been collated.
Before reaching a conclusion on whether NIHL of 3.2 dB was compensable, HHJ Platts considered the binding authorities on ‘actionable’ injury. The most recent case was heard earlier in 2018. In the case of Dryden, reported in edition 224 of BC Disease News (here), platinum salt sensitisation, an asymptomatic condition, constituted ‘sufficient damage to found an action for negligence or breach of statutory duty’.
At the Supreme Court, Lady Black distinguished Dryden from Rothwell v Chemical & Insulating Co Ltd [2008] AC 281. She did so on the basis that unlike pleural plaques, which are a mere marker of exposure to asbestos dust, platinum salt sensitisation constituted a change to the claimant’s ‘physiological makeup’, which carried the risk of subsequent allergic reaction to chlorinated platinum salts.
In Wiseman, however, accepting that de minimis is a question of fact in each case, HHJ Platts concluded that ‘3.2 dB impairment due to noise exposure’ was not compensable. Although the claimant had successfully argued breach of duty and causation, the claim had to fail.
His reasoning for finding in favour of the defendant and dismissing the claimant’s claim was, as follows [paragraphs 51 and 52]:
‘I accept that there is an injury, and that injury is that excessive noise has caused damage to the ear, identified by the audiological testing results. It is clearly damage to a small degree. The agreed evidence at trial was that it does not have any material, or to use another word “appreciable”, effect for the Claimant. In reality Mr Wiseman is no worse off because of the exposure to noise by his former employers. His perception of his hearing would be exactly the same now whether or not the Defendants had been in breach of their duty to him or whether or not he had been employed by them for those 11 years. As I have said, on the evidence available to me, he is not materially or appreciably worse off to any degree.
In my judgment the fact that he has a measurable hearing loss caused by noise is not of itself sufficient. It is not going to get any worse, there is to be no other condition developing from it. Unlike Cartledge and unlike Dryden, and on the authorities to which I referred, which would seem in my judgement to be consistent, he has to prove that it has made a material difference, that he is appreciably worse off as a result of the negligence. Given that both Professor Lutman says that he is not worse off and Mr Hasan agreed that it has made no difference, or that it was negligible, I just cannot find that that should sound in compensation’.
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Royal Opera House Granted Permission to Appeal ‘Acoustic Shock’ Ruling (BCDN Edition 253)
In edition 225 of BC Disease News (here), we reported on the case of Goldscheider v The Royal Opera House Covent Garden Foundation [2018] EWHC 687 (QB), in which a professional violist was successful in bringing a noise-induced ‘acoustic shock’ claim against his former employer.
Pre-Goldscheider, we discussed (here) that ‘acoustic shock’ had been associated with exposure to ‘high frequency, high intensity sounds through a telephone headset’.159 As a result, all of the medical research on this phenomenon was concentrated on the risk of ‘acoustic shock syndrome’ in call centre workers.
However, in March of this year, the High Court found in favour of the claimant on disputed medical causation. What is more, on assessment of alleged breaches of the Control of Noise at Work Regulations 2005, Mrs Justice Nicola Davies did not distinguish between a factory and an Opera House working environment. No special consideration was given to the practicality of enforcing blanket hearing protection during rehearsals and performances, nor elements of so-called ‘artistic compromise’.
It was anticipated that the defendant would seek to challenge the 1st instance ruling and last week, it was reported that the defendant had been granted permission to appeal, by Hamblen LJ, on all issues of breach of duty and medical causation.160
In an official statement, a spokesperson for the Royal Opera House said:
‘We believe this case has far-reaching consequences for the live music industry and creative sector in this country and we look forward to putting forward our case later next year’.
It is hoped that the Court of Appeal will ‘put an end to the limbo that live music producers, and musicians and performers have found themselves in since the first instance decision was handed down’.161
The appeal will be heard at the Court of Appeal in March 2019.
159 Acoustic shock: Position Statement (February 2018 HSE)
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Slater and Gordon to Dispense with its NIHL Team Before 2020 (BCDN Edition 254)
Yesterday, it was reported that David Whitmore, Chief Executive of Slater and Gordon (S&G), had begun informing staff that firm-wide redundancies are on the horizon, after the decision was made to disband the law firm’s noise- induced hearing loss (NIHL) team by the close of 2019.162
The majority of NIHL claims handling takes place in Leeds. It is understood that the Leeds NIHL presence will cease as of July 2019.
A spokesperson for S&G announced:
‘We have concluded the vast majority of our legacy noise induced hearing loss (NIHL) cases. Therefore, once these have been completed, we will no longer require capacity to handle such a high volume of this work and so our proposal is to reduce the size of the current NIHL team ...’
Of course, the ‘legacy NIHL cases’ are a reference to the end of a 3-year period, in which the claimant firm has handled almost 50,000 industrial disease claims. Most of these matters were acquired in 2015, upon completion of the £637 million Quindell takeover.
S&G’s latest annual report conceded that the UK arm of the business made ‘substantial losses’ through unanticipated underperformance with NIHL claims resolution. Furthermore, a lack of NIHL settlement created ‘inherent uncertainty’ when calculating prospective revenue.
Researchers Identify ‘Essential’ Hearing Loss Gene (BCDN Edition 254)
In a recent article, published in an October edition of the Journal of Clinical Investigation,163 researchers at the University of California, San Francisco, examine their discovery of a gene, which plays an ‘essential’ role in the onset of noise-induced hearing loss:164
‘We were able to go from observation to mechanism to treatment in one window of time, which was really exciting’.
The team of researchers, led by Professor of Neurology and Paediatrics, Elliott Sherr MD, was interested in the function of Tmtc4 (transmembrane and tetratricopeptide repeat 4) in brain development. At the beginning of their investigation, the Tmtc4 gene was deleted in mouse embryos.
One month after the mice were born, the researchers were surprised to discover that the mice without Tmtc4 were ‘almost completely deaf’. Congenital hearing loss was ruled out, as all test subjects had normal hearing function at birth.
Hearing loss is typically caused by damage to the sensory hair cells in the cochlea, which are responsible for detecting sound waves and transmitting auditory information to the brain. Hair cells cannot regenerate after they die.
In this latest study, deafness in mice was attributed to the deletion of Tmtc4. Dr Sherr’s group explained that Tmtc4 removal distorted the balance of calcium between the endoplasmic reticulum and the rest of the hair cell.
162 John Hyde, ‘Job losses possible as Slater and Gordon closes department’ (8 November 2018 Law Gazette) https://www.lawgazette.co.uk/practice/job-losses-possible-as-slater-and-gordon-closes-department/5068239.article> accessed 8 November 2018. 163 Jiang Li et al. Deletion of Tmtc4 activates the unfolded protein response and causes postnatal hearing loss, Journal of Clinical Investigation (2018). DOI: 10.1172/JCI97498 164 Jason Alvarez, ‘Gene plays critical role in noise-induced deafness’ (19 October 2018 Medical Xpress)
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Annotated diagram of a cochlear hair cell:
This calcium imbalance triggered an unfolded protein response (UPR) – a quality control system, whereby cells self- destruct to avoid producing faulty or dangerous proteins. Repeated ‘hair-cell suicide’ can cause hearing loss, ultimately leading to total deafness.
In further tests, the researchers exposed unaffected mice to loud aural stimuli and observed that hair cell death was triggered by the same UPR as the mice lacking the Tmtc4 gene. In this way, the researchers were able to deduce that the rapid hearing loss observed in Tmtc4-deficient mice was due to heightened sensitivity to normal sounds:
‘No one had shown that noise-induced hearing loss involved the unfolded protein response.
The UPR was therefore highlighted as a target for potential NIHL therapy.
In 2013, Peter Walter Ph.D, Professor of Biochemistry and Biophysics, identified a drug, called ISRIB (for Integrated Stress Response Inhibitor), which inhibits the UPR and prevents hair cells from self-destructing. The drug was able to reverse memory failure caused by traumatic brain injury and eliminate aggressive prostate cancer cells.
The researchers in the latest study found that mice, administered with ISRIB before they were exposed to loud noises, prevented hair cell damage and noise-induced hearing loss. Further research will concentrate on preventing age- related hearing loss.
A similar drug to ISRIB could one day be taken by employees in noisy workplaces as a form of hearing-protection.
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Feature: Second Audiograms Underscore Reliability: Pandya v Walkers Crisps Ltd & Anor (Leicester County Court, 2018) (BCDN Edition 257)
INTRODUCTION
Since mid-November 2018, we have become aware of two judgments on negligence liability in NIHL claims.
This week, our feature article examines the decision of Pandya v Walkers Crisps Ltd & Anor (Leicester County Court, 2018), in which limitation, breach, causation and NIHL diagnosis were contested.
In next week’s feature article, we will provide detailed analysis on Fotherby v Quibell And Sons Limited & 2 Ors (Sheffield County Court, 2018), the latest court ruling on running a de minimis NIHL defence.
THE FACTS
A 70-year-old claimant commenced proceedings in negligence against her former employers, claiming that she was exposed to substantial levels of noise over 30-year period of employment (1978-2008) as a packer (1978- 1980), quality controller (1981-1998) and laboratory technician (1999-2008). She attributed this noise exposure to her alleged hearing impairment.
After the case had been allocated to the fast track, DJ Reed granted an Order for the medical experts to give oral evidence. As a result, the entirety of the 1-day trial, which took place on 5 October 2018, concerned the parties’ expert medical evidence. Post-trial, counsel were directed to file written submissions and HHJ Hedley handed down judgment on 20 November 2018.
LIMITATION
The claimant first contacted her solicitors in 2015, 7 years after her employment with the defendants ended. The Claim Form was issued on 19 April 2016. Therefore, the defendants argued that the claimant had exceeded the 3- year limitation period for bringing their personal injury claim, pursuant to s.11(4) of the Limitation Act 1980.
Since the date of action accrued 5 years prior to issue, the claimant had to prove that her ‘date of knowledge’ was no earlier than 19 April 2013. In the alternative, the claimant sought to argue that the Court should grant s.33 discretion to exclude the 3-year limitation period.
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The claimant submitted that her ‘date of knowledge’ was ‘in around the middle of 2013 when she noticed tinnitus and a difficulty socially with hearing’. Whereas, the defendants contended that the claimant’s knowledge was obtained earlier. This was on the basis that the claimant acknowledged, in her oral evidence, that hearing protection was supplied in 1990 and that she often noticed symptoms of hearing loss. It was established that the defendants had made the claimant aware of the noise risk:
‘... we were told if we wore the earplugs our ears wouldn’t get damaged’.
HHJ Hedley considered, at paragraph 77 of his judgment, that the claimant’s ‘date of knowledge’ was 1990. From this date onwards, a ‘reasonable person’, armed with the claimant’s knowledge, would have considered their hearing impairment to be ‘significant’ and attributed it to their occupational noise exposure.
‘The corollary is obviously that if the ear plugs were not used, then their hearing might be damaged; ... the Claimant was then aware [in 1990] that the noise could cause damage to her hearing ... the Claimant was aware of hearing problems for some 20 to 30 years before she made the claim ... she accepted that in 1990 she was able to say that the noise was causing problems with her hearing ... she could not hear her children at home and she would shout’.
Turning to the discussion on the equitable application of s.33 discretion, the judge found that it ‘would not be equitable to allow the claim to proceed’, as there had been a ‘wholly unexplained delay’ between the claimant’s attendance of a hearing clinic, in 2013, the claimant obtaining an audiogram through solicitors, in November 2015, and the issuing of proceedings, in April 2016.
The claim was therefore dismissed, on the grounds of limitation alone. Regardless, HHJ Hedley made a determination on issues relating to breach, causation and de minimis, in turn.
BREACH OF DUTY
According to the claimant’s witness statement, as a packer, she worked at 1 of 3 packing lines, approximately 1 metre from a packing machine.
As a quality controller, the claimant initially worked approximately 1 metre away from 4 packing machines grouped together and 2 metres away from other machines on the packing line. When the site changed, there were 5
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packing lines, each with 24 machines, but the claimant remarked that the noise was similar to the original working premises.
In her final post, as a laboratory assistant, the claimant estimated that ¾ of her shift was spent ‘in very close proximity’ to the packing machines.
Adduced documents recorded noise surveys and noise assessments over a period of years at various locations overseen by the defendants:
23 July 1987
Noise levels were ‘mostly above the recommended level of 90 dB’.
5 October 1987
Noise levels of 4 packing lines were ‘over 90 dB(A)’ and 1 line between ‘89-90 dB(A)’.
12 February 1988
Noise levels were ‘either above the upper action level or ... just marginally below the value of 90 dB(A)’.
28 May 1991
Noise dose for an average 8 hour shift was between ‘87.1-91 dB(A)’, but ‘the wearing of suitable hearing protection ... would be particularly beneficial’.
3 May 1994 and May 1996
Noise levels were ‘at or below the 2nd Action Level (90 dB)’.
From 1990, when the claimant asserted that earplugs were first provided by the defendants, she admitted to wearing them at all times; signage made it clear that hearing protection was compulsory and was enforced by management, but was not accompanied by specific health and safety training on excessive continuous noise exposure. It was alleged that ‘the earplugs had a tendency to fall out and also to make the Claimant’s ears sore’. Witness evidence pertaining to another employee of the defendants, confessed that occupational health testing had been available since 1982, while health surveillance and hearing testing of employees had been introduced in 1990.
In the single-joint engineering report, dated 3 November 2017, Mr MD Williams reasoned that:
‘Based on the noise survey reports and date held by the expert relating to noise levels of machines similar to those described by the Claimant, her daily personal unprotected noise exposure frequently and regularly approached or exceeded 90bD(A)’.
He added, on the subject of noise protection, that:
‘If she had used good quality, correctly fitted hearing protection for 100% of the time in the noisy conditions, her daily noise exposure would have been less than 80dB(A)’.
This would have provided the claimant with ‘more than adequate protection’.
Mr Williams went on to perceive the effect of ‘variable’ exposure times, finding that daily noise exposure could not be calculated ‘with a high degree of accuracy’. It was advised that 70% utilisation could discount 1.5 dB(A) from the average noise dose.
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Specifically, it was concluded that the ‘unweighted estimate of the Claimant’s daily unprotected personal noise exposure was 89.7 dB(A) ... from 1978 to 1980 (ie below the 90 dB(A) threshold), and then 85.7 dB(A) for all other employment from 1980 through to 2008’.
In respect of lifetime noise exposure:
‘The cumulative unprotected NIL for the Claimant’s employment was 100.9dB(A), whilst the attenuated exposure on the basis of the Defendants’ evidence was ‘no more’ than 98.6bD(A) ... based upon an accumulation of the two periods of employment.
Mr Williams recalculated cumulative NIL to 97.5 dB(A), in response to subsequent Part 35 questions, submitted by the defendants. A further calculation, on the basis that ‘inefficient’ hearing protection could produce an attenuation range of between 0 dB and 10 dB, put lifetime NIL in excess of 100 dB(A), but this could not be trusted.
In light of engineering evidence, the judge accepted that the claimant’s noise exposure was ‘substantial’. However, the detail as to the precise level of exposure, was ‘unclear’. HHJ Hedley emphasised the importance of the engineer’s ‘equivocal’ statement that there had been no breach:
‘The figures in the revised table show that the noise exposure was less than the 90dB(A) recommended limit in the 1972 Code of Practice and from 1990 there was no breach of the Regulations. The evidence suggests that the Defendants took sufficient steps to discharge their statutory and recommended duties during the above quoted periods’.
The judge considered that the use of ear plugs post-1990 would have ‘substantially’ attenuated exposure and even though fitting caused issues ‘from time to time’, this was not a ‘significant problem’. It was also noteworthy, in discharging the defendants’ duty of care, that ear defenders were available to the claimant.
Although technically, noise exposure of ‘no less than’ 89.7 dB(A), from 1978 to 1980, could have been rounded up to 90 dB(A), the judge ruled that ‘mathematical “rounding up” ... does not discharge the burden of proof’.
All arguments considered, HHJ Hedley observed that the defendants were not in breach, on the balance of probabilities.
NIHL DIAGNOSIS AND CAUSATION
Mr Iqbal was instructed on behalf of the claimant to provide expert medical evidence, while Mr Parker was instructed on behalf of the defendants. The experts were in disagreement over the diagnosis of NIHL.
In reaching a decision as to whether the claimant’s hearing impairment was caused by noise exposure, it was necessary to determine which audiogram(s) was correct:
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Mr Iqbal based his report on 2 audiograms conducted at the Holiday Inn, Leicester, in 2015.
‘It was not conducted in a noise-attenuated soundproof booth but was (according to Dr Iqbal’s oral evidence) conducted in circumstances where the ambient noise level was less than 35dB’.
In his report, Mr Iqbal observed a difference of 5 dB between hearing threshold levels (HTLs) at some frequencies tested. Moreover, there was no ‘air-bone gap’ (i.e. bone conduction matched air conduction), but there was observable high-frequency sensorineural hearing loss and bilateral bulging of 10 dB. NIHL was measured at 12 dB, on the basis of audiometric testing conducted.
Mr Parker’s report was prepared following an audiogram and examination, which was undertaken on 12 March 2017.
In his report, the claimant’s hearing loss appeared to show an improvement from the ‘Iqbal Audiogram’, despite medical expert consensus dictating that sensorineural hearing loss is ‘irreversible’. There was no high-frequency hearing impairment, nor was there identifiable high-frequency audiometric notching or bulging. Failure to satisfy R1 and R3 of the Coles, Lutman & Buffin (CLB) Guidelines 2000 resulted in an audiogram which showed no evidence of NIHL. The defendants also argued that the engineer did not find lifetime NIL in excess of 100 dB(A), meaning that there was no satisfaction of R2(a).
Disapproving of Mr Iqbal’s diagnostic report, Mr Parker cited literature,165 which was the subject of our feature article in edition 88 of BC Disease News (here). Here, and in 2 other studies, Lie et al. noticed that features of diagnostic audiograms, e.g. notches, commonly occur in workers who are not exposed to noise.166 Thus, it is a genuine possibility that the CLB Guidelines may be over-diagnosing NIHL.
In the joint-medical expert report, it was agreed that the claimant’s tinnitus was too small to be considered part of the claim. It was also agreed that some degree of the claimant’s hearing loss was age-related (Presbyacusis). However, Mr Parker explained that, although ‘it is accepted that the Court can derive a diagnosis of noise deafness from the Iqbal Audiogram’, the ‘Iqbal Audiogram’ was unreliable.
Single Audiometry
The experts were in disagreement, especially, over the effect of repeat audiometry on reliability. The claimant expert argued that the result of a single test is less reliable than the results of multiple tests, where the results of the second test repeat the results of the first. Whereas, the defendant expert argued that the check for repeatability was undertaken in a single test. Accordingly, a second audiogram is only required if the first result is borderline.
Since BSA 2011 Recommended Procedure for Pure-Tone Audiometry was adopted, repeat testing is conducted in the same sitting to ensure consistent and reliable results-within 5 dB at each frequency and with the more sensitive threshold being taken as the true threshold.
That being said, principle consultant at the Institute of Sound & Vibration Research (ISVR), Brian Lawton, stated, in 2015, that:
‘For an individual test subject, a single audiogram is an unconfirmed determination of that individual’s state-of- hearing in both ears. Put more simply, a single audiogram is a guess’.
Here, HHJ Hedley considered that Mr Parker was correct in declaring that single audiometry encompasses repeatability and thus, to conduct a second test under the same conditions has the effect of ‘underscoring’ reliability.
165 Lie et al., ‘The Prevalence of Notched Audiograms in a Cross-Sectional Study of 12,055 Railway Workers (2015) Ear and Hearing (forthcoming) accessed 18 March 2015
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Averaging Audiometry
Having applied the concept of averaging to reach a positive diagnosis of NIHL, Mr Iqbal’s view was that ‘it is legitimate for two or more readings to be averaged’.
In Note 3 of the CLB Guidelines, it is proposed that:
‘If an average of two, several or many hearing threshold measurements at the relevant frequencies in a particular ear can validly be used, the “at least 10dB or greater” guideline may be reduced slightly, by up to about 3dB. In borderline cases, an average of all the audiograms available and acceptable for averaging should be used in assessing the evidence for or against the presence of a high-frequency hearing impairment, notch or bulge.’
However, identifying when averaging is an appropriate method is still an imperfect science. In edition 161 of BC Disease News (here), we reported that averaging of 2 significantly different audiograms (HTLs differed by 20 dB - more than the accepted margin of variability), in the case of Harbison v The Rover Company Limited,167 invariably produced a false diagnosis of NIHL. However, Mr Sharna, the claimant medical expert, was unchallenged in that instance and averaging was deemed to be a ‘recognised mainstream approach’.
Professor Lutman, historically, has been of the mind that averaging is acceptable when audiograms have been carried out at different times, as long as the audiograms are similar and are not ‘intrinsically different’. Conversely, Mr Jones and Mr Parker have adopted a more circumspect approach, on the basis that errors between tests tend to be largely systemic rather than random and the use of averaging lowers the burden of proof required for a diagnosis of NIHL.
On this issue, HHJ Hedley preferred the opinion of the defendants' medical expert. He explained:
‘When one of the Audiograms is wrong, in my judgment it cannot be appropriate simply to average the readings’.
Remarkably, the judge admitted that it had been difficult to assess the efficacy of any of the audiograms adduced in this case, as ‘neither of the experts who gave oral evidence actually carried out the tests’.
At paragraph 67, the judge prepared a summary of the issues in the present case:
‘I comment as follows: 1. The Iqbal Audiogram was repeated, whereas the Parker Audiogram was not. However, I accept Mr Parker’s evidence that in a single audiogram repeatability is tested. However, in terms of reliability, the presence of a second test underscores the position. 2. However, if in fact there was an issue about the reliability of the circumstances of the Iqbal tests, repeating the test on the same day in the same circumstances might not remove such concerns. It is not as though a further test had been undertaken on a different day in entirely different circumstances. 3. I accept that the Iqbal test was undertaken in conditions where the ambient noise was less than 35dB and that in such circumstances a proper hearing test can be undertaken. However, that is not the same thing as undertaking a test in a sound-attenuated booth or in “ideal” audiological conditions (which I find the Parker Audiogram was). In my judgment it is more likely that an accurate audiogram will be recorded in ideal conditions than in a hotel, even where the ambient noise is below the recommended threshold. 4. There is no suggestion that the Parker Audiogram was not carried out correctly. It is inherently unlikely that a patient will record better hearing scores than her actual hearing would dictate, and certainly not across a number of frequencies. The lower frequency scores in the Parker test were in fact similar to those in the Iqbal test, suggesting that the Parker test itself was not faulty. 5. I am accordingly drawn to the conclusion that the Parker test accurately set out the Claimant’s hearing in 2017. It follows that I find that the Iqbal test did not’.
As such, HHJ Hedley found in favour of Mr Parker and the defendants, at paragraph 67:
167 (Birmingham County Court, 13 October 2016).
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‘I therefore find, on the balance of probabilities, the Claimant does not have NIHL and the Claimant does not suffer from a hearing loss induced by noise from her employment with the Defendants’.
Feature: More Success with De Minimis NIHL Defence: Fotherby v Quibell And Sons Limited & 2 Ors (Sheffield County Court, 2018) (BCDN Edition 258)
INTRODUCTION
In last week’s feature article (here), we announced that this week’s feature would review the judgment of Fotherby v Quibell And Sons Limited & 2 Ors (Sheffield County Court, 2018). This is another post-Dryden168 noise-induced hearing loss (NIHL) case, to add to Harte169 (reported here), Nicholls170 (reported here) and Wiseman171 (reported here), in which defendants have sought to argue that noise-related hearing impairment up to 3 dB is de minimis non curat lex, i.e. does not constitute actionable damage.
At the Supreme Court, in Dryden (reported here), Lady Black reasoned, unanimously, that a ‘change to the physiological make-up’ of a claimant could not be described as de minimis’, but distinguished pleural plaques as 'nothing more than a marker of exposure to asbestos dust, being symptomless in themselves and not leading to or contributing to any condition which would produce symptoms, even if the sufferer were to be exposed to further asbestos dust.
It was cogitated, following the handing down of judgment, that workplace exposure to platinum salts, resulting in platinum salt sensitisation, was analogous to workplace exposure to noise, resulting in cochlear hair cell damage.
However, in all of the post-Dryden County Court judgments to-date, defendants have had success in raising de minimis as a defence. Below, we examine the court ruling in Fotherby in the context of recent case law.
THE FACTS
The claimant sought damages for NIHL, allegedly developed during the course of employment as a labourer and bricklayer with 3 former-defendant employers.
The claimant commenced employment with the 1st defendant, from 1970 to 1983; the 2nd defendant, from 1981 to 1986; and the 3rd defendant, from 1990 to 1991.
All 3 defendants disputed liability on limitation, breach of duty and causation.
A 2-day trial was listed for 17-18 September 2018, before District Judge Josling, at Sheffield County Court.
LIMITATION
Proceedings were issued on 6 October 2015. It was originally asserted, in the claimant’s witness statement, that his ‘date of knowledge’ was October 2013, i.e. within the limitation period.
However, the 1st defendant contended that, given increased use of hearing protection in 1990, the claimant would have attributed his hearing impairment to noisy employment. On cross-examination, the claimant agreed with the defendant and further agreed that his latest ‘date of knowledge’ would have been July 2011.
168 Dryden and others (Appellants) v Johnson Matthey Plc (Respondent) [2018] UKSC 18. 169 Harte v Hawker Siddeley Dynamics Ltd & 2 Ors (Wigan County Court, 2018). 170 Wiseman v Overhead Doors (GB) Limited (2018). 171 Nicholls v Osram Ltd & Anor (Newcastle County Court, 2018).
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As such, DJ Josling found that the claimant’s ‘date of knowledge’ was July 2011. The claim was therefore brought outside of the 3-year limitation period for personal injuries.
However, the judge concluded that it would be appropriate to grant s.33 discretion to exclude the relevant limitation period, as there was ‘limited prejudice’ to any defendant in allowing the claim to proceed.
N.B. Interesting Comments on Potential Hypocrisy of Disputing Limitation and Arguing De Minimis Injury
Evidently, contesting limitation requires the existence of a ‘significant’ injury [Limitation Act 1980, s.14(1)(a)], which the claimant has knowledge of. Even though the defendants’ position was not undermined, the judge highlighted the hypocrisy of raising a de minimis defence, which fundamentally relies on an injury being imperceptible, in conjunction with a limitation defence:
‘It may be said that there is something [of] a contradiction in the Defendants’ stance that the NIHL is de minimis and the limitation argument, given that the latter requires the hearing loss (albeit not perhaps necessarily the noise induced element) to be significant’.
The judge’s comments therefore emphasise the importance of ‘pleading in the alternative’ in a written defence, where all elements of negligence liability are disputed.
BREACH
Chris Dawson, the forensic engineer, was instructed to produce a single joint report, in which he presented daily personal noise exposure calculations.
The alleged sources of noise exposure in the course of the claimant’s employment with the defendants were ‘cement mixers, disc cutters, jackhammers and Stihl saws’.
However, the claimant’s assertions, in respect of time exposed to significant noise, were considerably shorter on cross-examination than in his witness statement. The judge explained that the claimant, despite ‘doing his best to recall matters to the best of his ability’, was ‘an example of how honesty and unreliability in a witness are not mutually inconsistent. It was difficult to place much weight on any assessment of time provided by the claimant’.
On the balance of probabilities, the claimant had failed to discharge the burden upon him to prove a breach of duty by any of the defendants.
Even though the claim had already failed by this point, the judge went on to analyse the medical evidence, in the event that his finding as to breach was wrong.
DE MINIMIS HEARING LOSS
The claimant instructed Showkat Mirza, Consultant in Otolaryngology at the Royal Hallamshire Hospital, to prepare a medical report. Mr Mirza’s report, dated 18 July 2014, concluded that the claimant has ‘suffered average NIHL of 3 dB over 1, 2 and 3 kHz together with some NIHL at 4 kHz’. A later, 2016 report, dealt with Part 35 questions.
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On the basis that the claimant expert’s initial findings were indicative of de minimis hearing impairment, Professor Mark Lutman, Emeritus Professor of Audiology at the Institute of Sound and Vibration Research, University of Southampton, was instructed on behalf of the defendants to provide his own desktop report.
Subsequently, the views of both experts were compiled in a joint report, dated 7 May 2017.
Pre-trial, the claimant made an application, pursuant to CPR 35 PD 3.2(6), to rely on 2 letters from Dr. William Whitmer, co-author of the McShefferty Papers. This was accepted.
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At trial, the experts gave oral evidence, which was pivotal to DJ Josling’s decision.
Issue 1: Did the claimant’s NIHL across 1, 2 and 3 kHz have any ‘noticeable’ impact on the claimant’s everyday hearing?
It was agreed, between the experts, that the claimant’s NIHL was between 3-4 dB. As such, the first contention between the experts was whether this level of impairment was appreciable. If it was not, then the defendants submitted that the NIHL was de minimis. Contradictory statements, given in oral evidence, had the effect of weakening the claimant’s claim.
Mr. Mirza made an admission that ‘2 dB NIHL or less’ across 1, 2 and 3 kHz was de minimis.
However, this was irreconcilable with a conflicting observation that ‘2 dB NIHL or over’, across 1, 2 and 3 kHz could be considered ‘significant’.
In his judgment, DJ Josling highlighted the extent to which the quality of expert evidence delivery can be persuasive:
‘... it is perhaps indicative that Mr. Mirza had not approached his evidence in the same meticulous way that Professor Lutman did’.
In addition, the claimant expert cited the Moore Paper: A review of the perceptual effects of hearing loss for frequencies above 3 kHz:
‘The mean estimate of the NIHL at 1, 2 and 3 kHz is only 2.4 dB, which would usually be considered as of no importance’ [emphasis added].
Mr. Mirza argued, unconvincingly, that Professor Moore’s inclusion of the word ‘usually’, implies that low-level NIHL across 1, 2 and 3 kHz may not be de minimis if there is also NIHL at 4 kHz.
Both experts also sought to use the McShefferty Papers to strengthen their arguments on hearing impairment across 1-3 kHz. In edition 233 of BC Disease News (here), our feature article provided detailed analysis of the authors’ verdict on ‘just noticeable’ and ‘just meaningful’ difference of speech intelligibility in the presence of background noise (speech-to-noise ratio, or SNR).
Professor Lutman criticised Mr Mirza’s preliminary contention that 3 dB NIHL was ‘significant’, as it lacked ‘scientific reasoning’:
‘Presumably when Mr. Mirza wrote his primary report, he would not have had the opportunity to study [the McShefferty papers]…. Those papers are the first I am aware of that have actually asked people with hearing impairment how big a difference is required to be detectable. Previously, opinions were clinician-orientated and lacking any evidence base. Those papers suggest that a substantially larger incremental hearing loss is required to be noticed’.
In the joint statement, Mr Mirza suggested that, although the Paper makes the presumption that 3 dB NIHL would cause problems hearing speech in background noise, the range of frequencies used to calculate NIHL were not comparable to the present case:
‘The paper pertains to an average 3 dB hearing loss over 0.5, 1, 2 and 4 kHz and not 1, 2, 3 kHz’.
To alleviate this problem, Professor Lutman advised, as follows:
‘It is important not to confuse SNR with hearing loss measured on the audiogram. In order to apply the results of the study to audiograms, it is necessary to translate the just-noticeable difference in SNR into an increment or decrement of hearing threshold on the audiogram. For that purpose, many publications could be used but the paper by Smoorenburg ... is suitable. Figure 10 of that paper allows a SNR difference of 3 dB to be translated into an incremental hearing loss averaged over the frequencies 2 and 4 kHz of approximately 24 dB. That increment is
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equivalent to an increment on the 1-2-3 kHz average of approximately 15 dB (these values should be treated as broad estimates). At face value, the combination of these studies suggests that an incremental hearing loss of 15 dB is required to be noticeable, which is much larger than non-evidence-based opinions that have been offered in the past (including by me). In my opinion, the value of 15 dB is probably too large; however, the McShefferty et al. study has caused me to recalibrate my opinion upwards and now I generally give the opinion that an incremental hearing loss needs to be at least 4-5 dB (binaural 1-2-3 kHz average) to be noticeable. For these reasons, I have offered the opinion that the claimant’s estimated incremental hearing loss of 3 dB is too small to be noticeable’.
The method of ‘translation’ (from SNR to incremental hearing loss), described by Professor Lutman (see the paragraph above), was unknown to the claimant medical expert.
DJ Josling acknowledged Professor Lutman’s ‘thorough, incisive and compelling’ command of academic Papers and the ‘familiarity’ with which he applied the literature to the claimant’s individual case, which Mr. Mirza was ‘unable to match’.
Further, the judge praised the defendant expert’s delivery of oral evidence, in the face of ‘rigorous cross- examination’:
‘... it was the substance rather than the style of his evidence that resulted in my preferring it to that of Mr. Mirza’.
Accordingly, the judge opined, at paragraph 54:
‘... on the balance of probabilities the NIHL at 1, 2 and 3 kHz does not have any noticeable impact on the Claimant’s everyday hearing ability, and accordingly the Claimant’s NIHL at these frequencies is de minimis’.
N.B. DJ Josling placed ‘limited weight’ on Dr. Whitmer’s letters, which were adduced by the claimant by way of late application.
Issue 2: Did the claimant’s additional NIHL at 4 kHz have any ‘noticeable’ impact on the claimant’s everyday hearing?
Turning to the second issue, the judge engaged in a debate over appreciable damage caused by additional noise-induced hearing impairment at 4 kHz.
Again, the claimant medical expert’s opinion was dependent upon the Moore Paper:
‘Professor Moore…states that the speech intelligibility index, a standard method for predicting speech intelligibility, calculated that 23% of the information of speech is carried by frequencies above 3 kHz. He concludes that mild or moderate noise induced hearing loss at frequencies above 3kHz would lead to increased difficulty in understanding speech in noise’.
By contrast, Professor Lutman, having been one of the initial peer-reviewers of the Moore Paper, cited the Evans172 case (reported here), in which he explained his concerns, which led him to recommend the rejection of the Paper. One of these concerns was Professor Moore’s failure to mention work produced by Professor Dobie:
172 Evans v Secretary of State for the Department of Energy & Climate Change and JJ Maintenance Limited (12th December 2017, Cardiff County Court)
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During the trial, Professor Lutman used Table 2 of the Moore Paper to calculate, check and re-check the claimant’s speech intelligibility index (SII):
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N.B. SII varies from 0 to 1. A SII of 0 infers that no useable information is conveyed, where a SII of 1 infers that all important information is audible to the listener. Incrementally, a SII of 0.75 is high enough for good communication with a clear talker in the absence of reverberation; a SII of 0.5 would mean that the listener has some difficulty with comprehending speech; while a SII of 0.3 would suggest that the listener has considerable difficulty in understanding speech and makes frequent errors.
Though Professor Lutman’s figures were unchallenged by Mr Mirza, the judge was able to find in favour of the defendants, on the second issue, as there was no difference between SII's for AAHL and actual hearing loss.
‘... the Claimant’s noise induced hearing loss, whether at 1-2-3 kHz or at 4 kHz, does not have any noticeable impact on the Claimant’s everyday hearing ability’.
In summary, the claim failed on breach arguments and failed to prove that the alleged NIHL constituted actionable injury. Professor Lutman was the more persuasive expert, with superior knowledge and application of the relevant medical research.
Fotherby is yet another example of defendants successfully arguing that low-level (2-4 dB) NIHL is de minimis, even when there is additional impairment at 4 kHz.
County Court Jurisdiction in Sea-Based Disease Claims: Meeks v BP Shipping and Fyffes (Unreported, 2018) (BCDN Edition 259)
When industrial disease claims are issued against multiple defendants in the County Court and some of the defendants are ship-owners, it is common practice for sea-based defendants to be treated as quasi land-based. Pursuant to CPR 19.2(2)(a), parties are ‘added’ to proceedings and the County Court has jurisdiction to determine matters in dispute in relation to all defendants.
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What happens when claimants commence County Court proceedings against sea-based defendants in the absence of land-based co-defendants, however?
The recent case of Meeks v BP Shipping and Fyffes (Unreported, 2018) draws attention an issue associated with claimant solicitors applying the Civil Procedure Rules routinely and, in this instance, erroneously.173
Here, the claimant, who was employed as a ship carpenter between 1974 and 1979, alleged that he had developed noise-induced hearing loss (NIHL) in the course of employment with 2 shipping companies. Purported exposure to injurious noise levels occurred while out at sea.
As such, the defendants contended that the claimant should have brought an Admiralty claim, in accordance with CPR 61.2(1)(a)(v), which refers to specific claims that fall under the jurisdiction of the Admiralty division of the High Court.
Section 20(2)(f) of the Supreme Court Act 1981 refers to claims for personal injury sustained as a result of a ship- owner’s negligence.
173 ‘Strike out application success in Admiralty personal injury claim commenced in the County Court’ (5 November 2019 Hill Dickinson)
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Despite the defendants’ pleadings that the present claim fell within the scope of s.20(2)(f), the claimant refused to discontinue the existing County Court action and start new proceedings in the Admiralty Court.
Thus, the defendants made an application to strike-out the claim.
At the application hearing, the claimant opposed the application on 3 grounds.
Firstly, that s.20(2)(f) did not apply to this case.
In the alternative, that the defendants, in disputing the County Court’s jurisdiction, should have made an application, under CPR 11.1(a) or (b), within 14 days of filing an acknowledgement of service.
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Finally, that striking out the claim would be a draconian sanction, when the court has powers of case management, under CPR 3, which allow for a matter to be transferred to the appropriate court, e.g. the Admiralty Court.
Taking each submission in turn, the judge found in favour of the defendants and struck out the claim. However, QOCS disapplication was unsuccessful, meaning that they were unable to recover their costs from the claimant.
In respect of the claimant’s first submission, the judge found that the claim constituted personal injury arising out of the management of a ship and thus engaged s.20(2)(f) of the 1981 Act. On the second issue, the judge considered that a Part 11 application was unnecessary, since the County Court had no jurisdiction to hear the claim. Further, in regards to the third submission, the County Court judge, having struck out the claim for lack of jurisdiction, should not have the power to make a secondary decision to transfer the case to the Admiralty Court.
Although this is not a binding judgment, it is an illustration of strict interpretation of civil procedure which has caught out claimant solicitors and resulted in a claim being struck out rather than continued or transferred to the more appropriate court.
Defendants should be wary of inattentive claimant solicitors commencing County Court proceedings on the assumption that the court can exercise its jurisdiction in all industrial disease cases. Plainly, the ruling in Meeks evinces that it cannot.
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Feature: Establishing Breach of Duty in NIHL Claims – ‘Peripatetic’ Noise Exposure and Absent Noise Surveys: Mackenzie v Alcoa Manufacturing (GB) Ltd [2019] EWHC 149 (QB) (BCDN Edition 261)
INTRODUCTION
In this week’s feature article, we consider the effect of a High Court judgment, handed down last Thursday, on breach of duty in noise-induced hearing loss (NIHL) claims.
This case tested the significance of a claimant’s allegation that, in order to ‘communicate he had to shout or use hand signals’, where there were no noise surveys to corroborate or refute a consultant engineer’s noise level/dosage calculations.
FACTS OF THE CASE
The case concerned a NIHL claim, commenced by a 72-year-old claimant against a former defendant employer (D1), at a factory operated by the 2nd defendant (D2). In his pleadings, he alleged that he was exposed to injurious noise levels in the course of his employment.
Noise Allegations
The claimant was employed by D1 as an apprentice electrician, between 1963 and 1968, at D2’s factory. He subsequently worked for another employer, between 1968 and 1976, also in D2’s factory. He attended work 7 days per week (6 when he was an apprentice), labouring 10 hour shifts (though this was deemed to be an exaggeration).
In his witness statement, he submitted that the following processes at D2’s strip mill were ‘noisy’: • The production of aluminium ingots; • The rolling of aluminium ingots; and • The chopping of rolled aluminium ingots with cutting machines;
He further stated that the following processes at D2’s extrusion mill were ‘noisier’ than the strip mill: • The heating of aluminium ingots; • The pressing of 500-5000 tonne aluminium ingots using compressors; • The cooling of aluminium ingots using blowers; and • The cutting of aluminium ingots.
The claimant’s job involved the installation, maintenance and repair of operating machinery. His witness statement purported that he would ‘never work more than a few feet’ from machinery which sometimes had to be switched on to find a fault. Jobs supposedly varied in length, from ‘minutes’ to ‘days’. What is more, he pleaded that no hearing protection was provided and that he was not warned about the dangers of exposure to excessive noise.
Of critical relevance to the court ruling in this case, the claimant stated:
‘... it was necessary to shout to communicate with my colleagues at very close distances or even resort to having to tap them on the shoulder in order to get their attention or lip read what it is they were trying to relay to me’.
Bringing Proceedings
The judge at 1st instance established that the claimant’s ‘date of knowledge’ was summer 2012, meaning that the claim was issued within the 3-year limitation period for personal injuries.
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In the claimant’s Particulars of Claim, it was alleged that his injuries were ‘caused by the negligence and/or breach of statutory duty of the defendants', their servants or agents’. Specifically, the claimant listed examples of negligence, e.g. the defendants:
‘a) Failed to make a noise assessment contrary to the Noise at Work Regulations 1989…, regulation 4, or at all … 1. i) Failed to investigate and take advice on the noise levels in the said premise[s]… 2. q) Failed to monitor the noise levels at the said premise[s] properly, sufficiently, frequently or at all to ensure the Claimant was not exposed to unsafe levels of noise’.
In response, the defendant made no admission on liability and put the claimant to strict proof.
ENGINEERING EVIDENCE
Mr Kevin Worthington was jointly instructed to produce expert engineering evidence.
D2 adduced no evidence at trial that noise surveys of D2’s factory had, or had not been conducted, in the course of the claimant’s employment. As a result, Mr Worthington was unable to refer to noise surveys when calculating the claimant’s noise exposure.
However, in similar aluminium production plants, Sound Research Laboratories Limited, in 1989, recorded varying machinery noise levels, from 80 dB(A) Leq to 106 dB(A) Leq. These readings decreased to between 75 dB(A) Leq and 88 dB(A) Leq when the machines were shut down.
On the basis of this information, albeit of ‘limited assistance’, Mr Worthington found that, although there were some areas of D2’s plant where the noise levels were likely to exceed 90 dB(A), the average level was would be unlikely regularly to exceed this.
He concluded:
‘Hence, without observation of contemporaneous noise surveys/measurements from the premises at which the Claimant worked, it is not possible to demonstrate, on the balance of probability, that his average daily noise exposure level would have reached or exceeded 90dB(A) during [this] period of employment. Hence substantiation of this claim on engineering grounds would be very difficult’.
Further, relying on guidance and assumptions alone, Mr Worthington suggested that the claimant’s NIL did not exceed 97 dB, between 1963 and 1968, and did not exceed 99 dB, between 1968 and 1976.
THE 1ST INSTANCE DECISION
Party Submissions
At 1st instance, the claimant submitted that D1, as an employer, owed the claimant a duty of care at common law and that D2, as occupier of the premises in which the claimant worked, owed him a duty of care at common law and a statutory duty under the Factories Act. Moreover, that:
‘At the time of the Claimant's employment those duties included a duty to monitor the level of noise at the factory in order to determine whether and if so, what steps needed to be taken to protect the Claimant from exposure to noise which might damage his hearing’.
Counsel for the claimant also argued that, since D2 had failed to disclose noise surveys, it was ‘to be inferred that none was carried out’.
The claimant relied on the Court of Appeal ruling in Keefe v Isle of Man Steam Packet Company [2010] EWCA Civ 683. Keefe regarded a NIHL claim, allegedly caused by noise exposure on the galley of a ship. The defendant was aware of the noise risk, as they had provided PPE for employees, but there was open acknowledgement that noise measurements had not been taken:
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‘There is no evidence that the defendants took any measurements of noise levels in their ships and the judge's finding is that they did not’.
Longmore LJ, giving judgment in Keefe, reasoned, at paragraphs 18 and 19:
‘... in the present case there is the potent additional consideration that any difficulty of proof for the claimant has been caused by the defendant's breach of duty in failing to take any measurements. The judge does not appear to have given any weight to this important factor.
If it is a defendant's duty to measure noise levels in places where his employees work and he does not do so, it hardly lies in his mouth to assert that the noise levels were not in fact excessive. In such circumstances the court should judge a claimant's evidence benevolently and the defendant’s evidence critically. … [A] defendant who has, in breach of duty, made it difficult or impossible for a claimant to adduce relevant evidence must run the risk of adverse factual findings. To my mind this is just such a case’.
By contrast, defendant counsel sought to distinguish Keefe on the facts, on the basis that the present case was ‘concerned with events 50 years ago’ and, unlike in Keefe, where the judge was able to make a finding that no noise surveys had been conducted, it was impossible to make the same assumption with certainty in the present case. The fact that documents created 50 years prior might not be available was hardly ‘unsurprising’.
HHJ Vosper’s Ruling
On 15 November 2017, His Honour Judge Vosper dismissed the claimant’s NIHL claim against both defendants.
At paragraph 33 of his judgment, he expressed his disagreement with the claimant’s submissions on the duty owed by D2:
‘... it is not possible to make a finding that [the Respondent] is in breach of duty in failing to carry out noise surveys’.
In addition, the judge was distrusting of the claimant’s account of historic exposure, at paragraphs 44 and 64:
‘It is likely that the information given to Mr Worthington exaggerates the Claimant's noise exposure ...
... the Claimant's evidence could not be regarded as sufficiently precise for me to reject the engineering evidence in favour of it. That is not to criticise the Claimant. It is simply unrealistic for him to be able to remember in detail the events of more than 50 years ago’.
Weighing up the quality of available evidence, including Mr Worthington’s concluding remarks that the claimant was not regularly exposed to noise levels above 90dB(A), he went on to find, at paragraph 58:
‘I do not accept the submission of Mr Johnson that I should ignore the engineering evidence because the Second Defendant has not produced noise surveys’.
Accepting the evidence of the single joint engineer, the claimant was judged to have failed to prove tortious exposure to noise by the defendants.
Subsequently, the claimant appealed against HHJ Vosper’s ruling, in respect of D2.
THE DECISION ON APPEAL
Party Submissions
On appeal, the claimant’s grounds of appeal were as follows: • D2 had not complied with its duty conduct noise surveys between 1963 and 2007 • HHJ Vosper should not have distinguished the case from Keefe. • On ‘benevolent’ interpretation of the claimant and ‘critical’ interpretation of the defendant, per Longmore LJ in Keefe, D2 tortiously exposed the claimant to excessive noise between tax years 1963/64 and 1975/76.
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• HHJ Vosper did not consider that D2’s duty to peripatetic workers, post-1972, was to avoid any exposure at or exceeding 90 dB(A). • In the alternative, that HHJ Vosper did not accept that D2’s duty to peripatetic workers, post-1972, was to avoid any exposure at or exceeding 90 dB(A).
By contrast, the defendant contended that HHJ Vosper’s judgment was ‘careful and considered’.
Regarding compliance of D2’s alleged duty to carry out noise surveys, the claimant cited page 5 of Noise and the Worker, where the guidance states that noise surveys can be carried out if an employer is aware of an ‘excessive noise’ problem:
In the 1963 version of the document, ‘excessive noise’ was identified by the co-existence of all 6 factors below:
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Then, in 1968, Noise and the Worker was revised to state that ‘excessive noise’ could be identified by the existence of just 1 factor. Thus, the claimant averred that from 1968, the duty to conduct noise testing applied to D2.
Garnham J’s Ruling
• Was there a duty to carry out a noise survey? And if so, when did this duty arise?
On this preliminary issue, encompassing the 1st ground of appeal, Mr Justice Garnham considered that ‘it could not be said there was a duty to conduct noise surveys at the second defendants' premises before 1968 but there was such a duty after 1972’, when the Code of Practice was published.
His reasoning was formulated, using extracts from Mr Worthington’s joint expert report:
‘... prior to 1972, a reasonable and prudent employer ... may have been unaware as to how to conduct a detailed assessment where they could engage the services of a specialist consultant’.
At paragraphs 27 and 28, the judge reached a conclusion:
‘Plainly, the duty to consider conducting a noise survey did not arise instantly upon publication of the 1968 edition. Had the defendants applied their minds to the issue ... they ought to have ... sought to obtain specialist advice. That advice, in all probability, would have included the need to conduct a noise survey.
Before concluding that there was an operative duty on the defendants to conduct such a survey, however, some allowance has to be made for the time it would take for a reasonably prudent employer to appreciate the effect of the 1968 edition, to identify appropriate specialist advice, to commission that advice and to receive and act upon the resulting report. In Baker v Quantum Clothing, a period of two years was recognised as reasonable for such a process. I see no grounds for a judge taking a different approach and, in those circumstances, I would hold that the Judge ought to have concluded that the defendant was under a duty to conduct noise surveys from 1970’.
• What was the consequence of D2’s breach, post-1970?
On assessment of this supplementary issue, covering grounds 2 and 3 of appeal, it was necessary for the judge to consider the effect of the defendant’s breach, in the context of Keefe.
Ultimately, Garnham J determined that the 1st instance judge was wrong to distinguish Keefe, on the facts. He went further, stating that in rejecting the application of Keefe, HHJ Vosper had not afforded ‘the claimant's evidence the beneficial [benevolent] interpretation which Keefe called for’, which would inevitably ‘concluded that the likelihood was that the claimant was exposed to tortiously high levels of noise’.
• What of grounds 4 and 5?
In a sparse section of the tail-end of the judgment, Garnham J considered the claimant’s 4th ground of appeal, which was not addressed at all in the 1st instance judgment.
Counsel for the defendant supported HHJ Vosper’s approach, which was seemingly to ignore the issue. Mr Worthington’s engineering evidence established that it was unlikely the claimant was exposed to noise above 90 dB(A). It was obvious, therefore, that a peripatetic worker would not have been exposed to a noise dose in excess of 90 dB(A) Lep,d. Whether or not the Code of Practice prohibited exposure above 90 dB(A) was a non-issue.
However, for reasons that are not clear, nor explained, the judge preferred the claimant’s argument, finding that ‘it was incumbent on the Judge to explain why he was rejecting the claimant's arguments or why he preferred the defendants’.
In light of all of the evidence and party submissions, the judge found in favour of the claimant on grounds 1, 2, 3 and 4 of the appeal and remitted the case to the County Court for assessment of damages.
Full text judgment can be accessed here.
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Since judgment was handed down last week, we have received confirmation from Patrick Limb QC, of Ropewalk Chambers, that their client (D2) intends to seek permission to appeal the High Court ruling. Once the appeal paperwork is drafted, we look forward to seeing the grounds of appeal which would be deliberated at the Court of Appeal.
In the interim, it is important to analyse the quality and the relevance of the High Court decision.
CRITICAL ANALYSIS
At paragraph 28 of the judgment on appeal, Garnham J stated that:
‘As there was evidence that there were communication difficulties in the workplace [difficultly hear each other speak] then from 1970 there was a duty to carry out noise surveys. Failure to do so was breach of duty’.
From 1970, the only guidance available was the Ministry of Labour publication, Noise and the Worker (1963) and the Department of Employment publication, The Code of Practice (1972). Both of these documents were non- binding and both sought to achieve an aim; namely that long-term exposure to noise, which would equate to a damaging overall quota of noise, should be avoided.
If judges translate this guidance as being equivalent to the binding Noise At Work Regulations (1989), this raises a potential issue – which parts of the pre-1989 guidance is binding?
The reality is that, in most cases, a claimant’s historic recollection of communication interference will be the only available witness evidence. In this scenario, even though noise levels were likely to be well below the threshold of action, the defendant was effectively rendered in ‘automatic’ breach of duty, UNLESS they were able to produce evidence of noise surveys. The decision had the effect of reversing the burden of proof from the claimant (proving excessive noise exposure) to the defendant (proving under-excessive noise exposure).
However, claimant recollection of historic events has also been the subject of criticism in previous case law. In the High Court case of Parkes v Meridian Ltd [2007] EWHC B1 (QB), HHJ Inglis stated, at paragraphs 133 to 136:
‘In some cases where there are no direct surveys of the Claimant’s workplace reference has to be made to other surveys, and there is a degree of the application of judgment based on the expert’s experience in arriving at at least a bracket of likely exposure. Reconstructing noise levels is not a precise science.
As Professor Lutman I think accepted, anecdotal evidence is likely to yield to scientific evidence ... Descriptions of the need to raise voices are very subjective ...
... I do not think that the decision on noise levels at any of these factories, given the scientific evidence that there is, can in these cases be affected by the lay witness evidence referred to above. I do not think it appropriate to take a level or bracket coming from the engineering evidence, and adding to it because of the description given by witnesses’.
The Inconsistent Application of Keefe
Before inspecting why Garnham J overturned HHJ Vosper’s distinction of Keefe in the present case, we should consider how the courts have previously distinguished Keefe.
In Heavey v TMD Friction Ltd (Wakefield County Court, October 2012), the Court was convinced, without hesitation, that it cannot be safely and properly inferred, 30 years after the event, that the historic absence and inability to locate evidence of testing is proof that no testing was undertaken. In his judgment, HHJ Cockroft referred to Keefe as being ‘almost the exact converse of the present case’, as noise levels were ‘routinely measured’. Like Mackenzie, there had been no admission of a failure to measure noise levels.
Similarly, in Caines v Sandbanks Yachting Ltd & 2 Ors (Southampton County Court), HHJ Burrell QC found that Keefe ‘had no application to the facts of the case’. Here, the alleged noise exposure took place in the early 1970’s and
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the only evidence that the defendant could adduce was ‘snapshot’ photographs of machinery on a large site, where noise exposure could vary enormously.
In Mackenzie, the defendant was unsuccessful in distinguishing Keefe on the following 4 grounds: • Here, the 1989 Regulations did not apply, whereas they did in Keefe. • Unlike in Keefe, there was no positive evidence to suggest that noise surveys had not been carried out. • It was foreseeable that documents could have been lost, due to a longer passage of time than in Keefe. • Here, there was expert engineering evidence, whereas in Keefe, there was none.
The judge on appeal did not consider that any of these distinctions constituted ‘good grounds’ to depart from Keefe.
His rejection of the defendant’s 1st argument was based on the existing duty to carry out surveys, expressed in guidance published before 1989. We reiterate that Noise and the Worker was never intended to have binding effect and nor was the Code of Practice.
His rejection of the defendant’s 2nd argument was based on the claimant not having seen surveys. However, it is surely reasonable to think that you cannot imply documents into existence just because they are not found.
His rejection of the defendant’s 3rd argument was based on his own expectation that some documents would exist. This is a staggering prospect, given that the most recent exposure occurred some 42 years earlier.
Finally, his rejection of the defendant’s 4th argument was based on the engineering evidence, which provided no ‘positive evidence’ on noise levels. This appears, from the judgment alone, to be incorrect. Mr Worthington concluded that it was unlikely that the Claimant was regularly exposed to noise above 90 dB(A) – a positive finding if ever there was one.
THE WIDER IMPLICATIONS
Doughty Street Chambers, who acted for the claimant, have heralded their success at the High Court as giving rise to ‘wide implications for claimants seeking compensation for hearing loss and other industrial diseases’.174
They go on to claim that:
‘It makes clear that, when a defendant is under a duty to measure levels of a toxin (such as noise, or dust), they must provide those measurements, or explain why they cannot do so, otherwise a claimant may establish breach even in the absence of supportive expert evidence’.
But, to what extent is this acclamation genuine?
Mackenzie is an appeal from a Circuit judge and is therefore binding on the Circuit bench, in theory.
However, Keefe, a Court of Appeal decision, has a higher standing than Mackenzie, which means that defendants are still open to argue, as they have in previous case law (see above), that Keefe does not apply on the facts of subsequent cases heard in court.
The most apt description of Mackenzie, therefore, is that it is an application of Keefe on a specific set of facts. When faced with a different set of facts, one might expect that a judge would reach an alternative outcome.
What if Mackenzie was followed, hypothetically?
One might envisage, if Mackenzie was unsuccessfully appealed at the Court of Appeal and had equal standing with Keefe, that it could not reasonably be followed in a number of circumstances.
174 ‘Christopher Johnson succeeds in High Court industrial disease appeal’ (1 February 2019 Doughty Street Chambers)
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For example, to apply Mackenzie in a NIHL case involving a dissolved entity, it would surely be an oversight to punish a defendant of this status from providing documents that are no longer available.
What is more, in the context of asbestos case law, Doughty Street’s interpretation of the Mackenzie judgment would appear to suggest that from 1970 onwards, thanks to the introduction of the 1969 Asbestos Regulations, a defendant’s failure to adduce asbestos testing evidence would result in an ‘automatic’ finding on breach.
Nonetheless, if Mackenzie is merely an application of the Keefe judgment to a specific set of facts, we argue that Mackenzie is not intended for broad brush application. This view would seem to be consistent with the decision in Garner v Salford City Council [2013] EWHC 1573 (QB), in which Keith J stated, at paragraph 28:
‘The case is unlike Keefe v The Isle of Man Steam Packet Co Ltd [2010] EWCA 683 (Civ), in which the Court of Appeal held that the defendant could not assert that it had not been proved that the noise levels on its boats were excessive when in breach of duty it had failed to measure those levels. There was no duty on the company in 1978 to check the lagging for asbestos, only guidance, and it was sufficient compliance with that guidance for the company to proceed on the assumption that it contained crocidolite’.
To ward off future danger of the Mackenzie judgment, insurers could benefit from producing their own evidence, which provides a legitimate explanation as to why noise surveys cannot be located, e.g. because the only person who could say whether or not testing was undertaken is now deceased. To rely solely on submissions, as the defendant did in the present case, may be met with risk, in the light of Mackenzie.
£1.3 Million Military Deafness Claim Listed for High Court Trial in March (BCDN Edition 262)
A former Royal Marine is seeking damages of £1,275,899 million from the Ministry of Defence (MoD) for noise- induced hearing loss and tinnitus.175 Given the abnormally high level of compensation sought, the trial of liability is scheduled to be heard in the High Court next month. It is considered to be a landmark case – the first of its kind and a potential test case for future military deafness claims.
175 Dominic Nicholls, ‘Former Royal Marine sues MoD for hearing loss, in case that could cost millions’ (12 February 2019 The Telegraph)
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Mr Alistair Inglis, who now uses a hearing aid, alleges that his hearing impairment was caused by prolonged exposure to the noise of weapons and vehicles during 14 years of military service, eventually forcing him to leave in 2012. Somewhat ironically, Mr Inglis currently works in health and safety.
The claimant’s submissions on breach of duty have been summarised by Mr Simon Ellis, his solicitor at Hugh James, as follows:
‘Essentially, we say he was not given the right protective equipment to mitigate against noise exposure. We also say that hearing tests he had in the Marines did not pick up the level of hearing loss from which he now suffers’.
The question of when military personnel are owed a duty of care is a much-debated topic.
High ranking military officials are of the opinion that combat activity should be immune from legal action, while claimant lawyers argue that the MoD’s duty to safeguard its servicemen and women does not cease after troops leave the training ground.
In editions 257 (here) and 259 (here) of BC Disease News, respectively, we reported on a non-freezing cold injury claim and a Q fever claim, both of which were brought by former servicemen. In the former claim, the soldier argues that his condition was developed as a result of cold conditions in UK-based training exercises, while success in the latter claim relies on the Central London County Court finding that the soldier was infected with Helmand- fever bacteria in Helmand province – a war zone.
In this particular claim, the 39-year-old pleads that his injurious exposure ‘was a combination of both training and combat exposure’, as inadequate hearing protection was supplied both in and out of action in Afghanistan.
The MoD disputes the ‘extent’ and ‘precise cause’ of the claimant’s hearing loss. From this limited snippet of information, it could be implied that audiometric testing has produced audiogram(s) which are not consistent with NIHL and are therefore not diagnostic of NIHL.
In the financial year 2016/17 alone, the cost of service-related employers’ liability (EL) claims was £60 million.
The latest Government figures show that service-related NIHL claims are the most common type of claim, although the number of claims is generally falling. Between 2014 and 2015, there were 1,838 NIHL claims, which is more than double the number of claims between 2016 and 2017 (914).
Nonetheless, claimant counsel, Ronald Walker QC, has stated that 210 veterans are in the process of bringing legal action against the MoD, from all three branches of the armed forces. Mr Ellis described that these army, navy and air force personnel have ‘all been exposed to excessive noise, either from weapons systems ranging from pistols and rifles to the big artillery pieces, or from items such as military vehicles, tanks, ships and aircraft’.
Each of these 210 claimants is pleading that personal protective equipment (PPE), supplied in training and in combat, was ineffective. Mr Ellis further explained:
‘There is protection available which is specifically designed for combat situations. The problem is that the military was not always very good at getting it’.
This may soon change, however. In edition 257, we announced that the Defence and Security Accelerator (DASA) is funding trials and demonstrations of new noise-induced hearing loss (NIHL) technology, which could become standard combat equipment in the near future.176
Will the parties in Mr Inglis’ case reach settlement before trial? We will continue to provide updates if and when more information is made available.
It is worth bearing in mind that under the Judicial College Guidelines (14th edition) bracket, labelled ‘Severe tinnitus and hearing loss’, the upper limit of general damages is £39,940 (with the 10% uplift). A significant proportion of
176 Defence and Security Accelerator, ‘Wearable technology for injury prevention’ (17 December 2018 GOV.UK)
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this claim is therefore made up of special damages, most likely future loss of earnings and pension, pertaining to a relatively young claimant.
Royal Marine Reaches Agreement with MoD Over £1.3 Million Deafness Claim (BCDN Edition 265)
In edition 262 of BC Disease News (here), we reported that a 39-year-old, former Royal Marines Platoon Weapons Instructor, Alistair Inglis, was pursuing a £1,275,899 million claim for noise-induced hearing loss (NIHL) and tinnitus, allegedly caused by the Ministry of Defence’s (MoD) negligence.
It was the claimant’s pleaded case that, for 1 and a half decades, he experienced ‘a combination of both training and combat exposure’ to weapon and vehicle noise, which resulted in hearing impairment supposedly ‘equivalent to that of a man in his early 70s’. He served in Northern Ireland and Helmand province, Afghanistan.
Hugh James (the claimant’s solicitors), summarised the claimant’s submissions, as follows:
‘Essentially, we say he was not given the right protective equipment to mitigate against noise exposure. We also say that hearing tests he had in the Marines did not pick up the level of hearing loss from which he now suffers’.
The trial of liability, listed to be heard at the High Court this month, was a potential landmark case. It was going to be the first its kind to tackle the issue of when military personnel are owed a duty of care.
High ranking military officials are of the opinion that ‘combat’ activity should be immune from legal action, while claimant lawyers argue that the MoD’s duty to safeguard its servicemen and women does not cease after troops leave the training ground.
Some considered Mr Inglis’ claim to be a test case for future military deafness litigation, which is the most common type of service-related claim. The MoD is currently facing 200 similar claims.
However, this week, the Telegraph reported that the ex-military man has reached an out-of-court agreement with the MoD on issues of liability.
At the High Court on Monday, claimant counsel told Judge Peter Marquand that issues had been resolved ‘80:20 in the claimant's favour’.177
It is now necessary for Mr Marquand to determine a suitable award of damages.
The claimant’s schedule of loss sought general and special damages (loss of future earnings, loss of pension and for the cost of hearing aids), but the MoD insists that he should only be awarded general damages and the cost of hearing aids.
The claimant argues that he left his ‘lucrative line of work’, including the right to receive a full pension (after 22 years of service), ‘for the sole reason that he had concerns about his deteriorating levels of hearing’:
‘[It was] highly unlikely that [Mr Inglis] would have abandoned his successful military career and those mid-term financial rewards had it not been for his noise-induced hearing problems’.178
Whereas, the MoJ contends that he left voluntarily, while still ‘fit for all duties’, with ‘no prospect of being medically discharged’. Should he have stayed in his role, MoD witness, Sam Healey, wrote that it was ‘likely that [Mr Inglis] would have been offered employment in a specialisation with reduced noise exposure’.
177 Dominic Nicholls, Former Royal Marine reaches agreement with MoD after suing for hearing loss (4 March 2019 The Telegraph)
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Mr Healey further asserted that his subsequent job role, in maritime security, was not only ‘an occupation that involves exposure to gunfire’, but also paid him ‘considerably more’ than as a Royal Marines Sergeant. His post- injury civilian salary (his current Health and Safety Office role) was also deemed to be ‘broadly similar’ to his earnings ‘had he not suffered noise-induced hearing loss’.
Feature: Fundamental Dishonesty Under Section 57 of the Criminal Justice and Courts Act 2015: A Matter for Trial or Interlocutory Application? (BCDN Edition 265)
After the Legal Aid, Sentencing and Punishment of Offenders Act (LASPO) 2012 came into force, a finding of ‘fundamental dishonesty’ in post-April 2013 personal injury claims is the best eventuality for Defendants, in respect of costs. Perhaps second only to an order for wasted costs, enforceable against the claimant’s solicitors, which provides the added security that costs orders are recoverable one way or another. Helpfully, if early warning is provided to the claimant’s solicitors, as to the evidence of fundamental dishonesty, the door is also left open for wasted costs.
‘Fundamental dishonesty’, under s.57 of the Criminal Justice and Courts Act 2015, is typically determined at trial. By this stage of proceedings, a defendant will likely have incurred significant costs and the order for costs that they achieve against an uninsured claimant, often with no means to pay, can hardly be described as a good result. Put frankly, it would be cheaper to settle the claim than incur the additional costs.
Naturally, discrepancies in lay evidence often need to be tested at trial and there is very little a defendant can do, except wait for a claimant to expose themself as fundamentally dishonest on cross-examination. For example, if there is an exaggeration of the injury suffered (see last week’s article on the case of Smith179 here), or the past/future losses incurred (see the LOCOG180 case here).
However, what about circumstances where there is ‘clear evidence’ of fundamental dishonesty from the beginning, which do not need to be tested at trial? For example, if evidence of a prior claim invalidates the claimant’s date of knowledge, for the purpose of bringing a claim within the relevant limitation period. Alternatively, if the defendant obtains video footage, which shows that the injury is a total fabrication.
It could be seen as an oversight that the CPR provides no obvious low-cost vehicle for bringing the issue of ‘fundamental dishonesty’ to the Court’s attention pre-trial. None of the CPR 3.4(2) criteria are obviously met.
179 Smith v Ashwell Maintenance Limited (Leicester County Court, 2019). 180 London Organising Committee for the Olympic and Paralympic Games (in Liquidation) v Sinfield [2018] EWHC 51 (QB).
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On the basis of ‘fundamental dishonesty’, it cannot be said that the claim has ‘no reasonable grounds’. It could be argued that the statement of case containing the ‘fundamental dishonesty’ is an ‘abuse of process’, but would the Court ever be prepared to make such a finding before the claimant has had an opportunity to give evidence? Clearly, there is no breach of a rule, practice direction, or court order.
Accordingly, defendants are almost invariably forced to file a Defence and reserve all discussion on fundamental dishonesty until the trial on liability.
What is more, summary judgment does not avoid a defendant’s obligation to file a defence, which will likely trigger an absolving reply or an application from the claimant to amend the Particulars of Claim.
Recently, BC Legal were instructed to act in a claim with a pleading of knowledge within the past 3 years. However, there was unquestionable evidence of the same claim, albeit abandoned pre-litigation, having been presented over 10 years ago. In this instance, we questioned how this claim could be disposed of quickly and in the most cost-effective manner for our client.
Despite presenting inconvertible evidence of the previous claim to the claimant’s solicitors, our threats of ‘fundamental dishonesty’ and wasted costs failed to secure a discontinuance. Subsequently, we advised our client to tackle this issue head-on, with a strike out application.
This week, we report that BC Legal were successful in achieving a finding of ‘fundamental dishonesty’ at an application hearing, without having to file a Defence and without incurring much in the way of costs. To our knowledge, this is the first example of a Judge finding ‘fundamental dishonesty’ before trial.
Our application to contest jurisdiction relied upon s.57 and the dicta of Mr Justice Knowles, in LOCOG. We commenced a ‘two pronged’ approach, with a request for the claim to be struck out, in accordance with CPR 3.4(a). If there is ‘fundamental dishonesty’ upon any issue that goes to the ‘heart’ or ‘root’ of the claim, then the 2015 Act has the effect of dismissing not just that one issue, but the entire claim. We considered that if dishonesty over gardening expenses surpassed this threshold, then dishonesty over limitation would be sufficient.
In essence, our two-fold argument was as follows; in view of the fact that the entire claim would eventually be dismissed, by virtue of s.57, there were ‘no reasonable grounds’ for bringing the claim, which meant that the claim could be struck out immediately. The District Judge, sitting at Birmingham County Court, was satisfied that the application was appropriately presented and made a finding of ‘fundamental dishonesty’, in the absence of evidence from the Claimant.
It is fair to say that in achieving such a result, the evidence of ‘fundamental dishonesty’ had to be unquestionable, to the extent that the Judge was prepared to make the finding without contribution from the claimant. With that
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being said, the Court has case management powers to call a claimant to give oral evidence at an application hearing [see CPR 3.1(2)(d)], which would be a significantly more cost-effective option than proceeding to trial.
It is important to highlight that this is a 1st instance decision, though no permission to appeal was given. Regardless, this dual-limbed application appears to be indisputable and we are confident that it can be deployed in any case with ‘clear evidence’ of ‘fundamental dishonesty’, even if suspicion of ‘fundamental dishonesty’ comes to light part- way through the proceedings.
Plainly, caution should be applied when determining the standard of ‘clear evidence’, as Judges are only likely to dismiss the most obvious of cases. We predict that ‘fundamental dishonesty’ relating to factual disputes, ambiguous evidence, withheld evidence and inconsistent evidence will still need to be tackled in the usual way, i.e. at trial.
As a result of this finding, our client’s costs were assessed on an indemnity basis, with no reductions applied to the Schedule of Costs. Since the claimant’s solicitors appear to have failed to act upon the warnings of ‘fundamental dishonesty’ and left it until the day before the hearing to serve a discontinuance, the Judge gave leave for the defendant to seek an order for wasted costs if the claimant does not pay within 14 days.
We consider this result to be exactly the sort of windfall that a defendant deserves, where the ‘fundamental dishonesty’ is a black and white issue.
The case was handled by Stuart Bacon, Head of BC Legal’s Southend Office. Please do not hesitate to contact Stuart by email if you have a similar case, or indeed any procedural irregularities that you would like to discuss.
US Military Invests in Drug to Inhibit NIHL Onset (BCDN Edition 266)
This week, researchers at Washington University School of Medicine in St Louis secured a $10.5 million grant from the US Department of the Army to investigate whether an anti-seizure drug, zonisamide, would be an effective noise-
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induced-hearing loss prevention drug for military personnel, if it was taken several hours before exposure to extremely loud noise.181
In last week’s edition of BC Disease News (here), we reported that an ex-Royal Marines Platoon Weapons Instructor had reached an agreement with the Ministry of Defence (MoD) over the Government’s liability for NIHL and tinnitus suffered in the course of his employment.
Alistair Inglis’ claim was 1 of around 200 similar military deafness claims, these being the most common type of service-related EL/PL claim.
He developed hearing impairment supposedly ‘equivalent to that of a man in his early 70s’ and attributed this to 1 and a half years of exposure to weapon and vehicle noise, both in combat and in training.
The question of when military personnel are owed a duty of care is still untested, as Judge Peter Marquand’s only determination, at the High Court, will be a suitable award of damages.
High ranking military officials are of the opinion that ‘combat’ activity should be immune from legal action, while claimant lawyers argue that the MoD’s duty to safeguard its servicemen and women does not cease after troops leave the training ground.
In edition 257 (here), we revealed that the UK Defence and Security Accelerator (DASA) was spending £1 million on 6 months of trials and demonstrations of new NIHL personal protective equipment (PPE), for use in combat operations.182
Will the technology trialled be as successful as zonisamide, however?
In animal testing, zonisamide has been shown to protect hearing when administered in advance of exposure to high noise levels. It blocks numerous chemical signals which nerve cells use to communicate.
Lead Researcher and head of the Department of Otolaryngology at Washington University, Craig Buchman, MD, is optimistic about the upcoming clinical trials:
‘There are no drugs available for the prevention of noise-induced hearing loss. Rather than try to develop a new drug from scratch, which takes tremendous time and resources, our approach repurposes a drug that’s already approved by the Food and Drug Administration for treating [epileptic] seizures. It’s known to have a good safety profile [i.e. few side-effects], and it’s already available in generic form. We’re hopeful that this drug will provide a way to protect hearing for people who we know will be exposed to hazardous levels of noise’.
Zonisamide will be tested in 2 different settings.
Washington University researchers will observe the effect of the drug in patients exposed to the sound of a drill when undergoing skull surgery, e.g. to remove a tumour.
By contrast, collaborating researchers, from the University of Akron, Ohio, will evaluate the effect of the drug in police officers exposed to the sound of gunfire at a shooting range.
In both study groups, test subjects will be randomly assigned to receive 1 of 2 zonisamide doses, or a placebo. They will take their assigned medication 4 hours ahead of noise exposure and undergo hearing tests both preceding and proceeding exposure.
We will continue to monitor the outcome of this trial with great interest, especially given the ongoing uncertainty surrounding the Government’s duty of care owed to military personnel in combat zones.
181 Julia Evangelou Strait, ‘$10 million to help study noise-induced hearing loss’ (11 March 2019 Washington University School of Medicine in St Louis)
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Court of Appeal Judgment Reserved in Acoustic Shock Appeal (BCDN Edition 268)
Previously, we reported (here) that the Royal Opera House (ROH) had been granted permission to appeal a High Court decision on ‘acoustic shock’. 183
Figure: The Royal Opera House, Covent Garden – Plate 100 of Microcosm of London (1810)
(Source: Wikimedia Commons)
At 1st instance (we first reported on this here and subsequently in greater depth here), a professional violist successfully argued that he had suffered ‘acoustic shock’ when sat in an unfamiliar position during a rehearsal session, on 1 September 2012, which ‘prevented his return to music’:
‘... the sensation from so many [18 to 20] brass instruments playing directly behind him, in a confined area, at the same time at different frequencies and volumes, created a wall of sound which was completely different to anything he had previously experienced’.
For clarification, it was argued that the principal trumpet, who was playing a part of music that the claimant would not have been prepared for in his new seating position, constituted an ‘acoustic incident’, i.e. a high intensity, unexpected, short cluster of noise exposure, which evaded the involuntary contraction of middle ear muscles (the stapedius reflex) to reach the inner ear.
183 Goldscheider v the Royal Opera House Covent Garden Foundation [2018] EWHC 687 (QB)
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Figure: The Middle Ear
(Source: Wikimedia Commons)
In a vestigial, innate response to the threat of potential injury, ‘acoustic startle’ occurred, which caused the ear to produce toxic metabolites. This physiological response led to a combination of symptoms, which ordinarily include deafness, pain, tinnitus and dizziness.
Since ‘acoustic shock’ is dependent upon an additional element of surprise, it will often affect individuals with anxiety, psychological issues, or stress.
In October 2018, we reported that the case was scheduled to be heard on appeal this month. In fact, the 2-day appeal took place on 19 and 20 March.
We have since been notified that judgment has been reserved for approximately 3 months. Detailed analysis of the Court of Appeal ratio can therefore be expected in a summer edition of BC Disease News.
Regardless of whether the Court of Appeal upholds or overturns the lower court ruling on liability (breach and causation), both parties have confirmed that they will launch an appeal if they are unsuccessful. Pending permission of the Supreme Court, therefore, it is likely that the case will soon be bound by the highest judicial authority in England and Wales.
If higher courts find in favour of the claimant, this could result in an influx of occupational disease claims for a various reasons: 1. Increased acceptance of ‘acoustic shock’ by medical consultants could result in more clinical diagnoses. o Although Mr. Parker favoured an ‘acoustic shock’ diagnosis in the ROH musician case, until recently, recognition of the condition was uncommon among Ear Nose & Throat (ENT) surgeons and specialists in otolaryngology – they were more inclined to diagnose Meniere’s disease. 2. ‘Acoustic shock’ would not be a condition exclusive to workers who wear telephone headsets. o Historic medical literature on ‘acoustic shock syndrome’ has typically concentrated on call centre worker exposure to electronically-generated white noise and prevalence of the condition.
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3. Perhaps the most damaging impact – to bring any type of occupational hearing impairment claim, noise exposure may not need to be a by-product of work, i.e. deliberately created noise may be tortious. The floodgates could hypothetically open to claims brought by musicians, entertainers, theatrical actors, etc. (a recent study of 443 Danish symphony orchestra musicians concluded that 19% had reported that severe tinnitus had had a severe impact on their daily lives).184 o At 1st instance, the ROH relied upon the importance of maintaining ‘artistic value’ and ‘reputation’ of the opera company as a means to defend breach, but were unable to compromise their standard of care on this basis. In effect, musicians are entitled to the same level of protection as any other worker, according to the High Court.
NIHL Claimant May Face Committal Proceedings for ‘Lying’ (BCDN Edition 270)
Defendant employers’ liability (EL) insurer, Zurich, has appealed an application for permission to make a committal application against an occupational deafness claimant, after ‘extensive investigations’ into his social media, in early 2017, revealed that noisy hobbies outside of work had been undisclosed throughout the course of litigation.185
69-year-old, David Romaine, sought £5,000 in damages from his defunct employer, Stanley Refrigeration Ltd, pleading that his noise-induced hearing loss and episodic tinnitus had developed as a result of his employment as a fridge engineer, in the 1970’s and 1980’s.
The Daily Mail reported that:
‘When asked [it is not clarified whether this was in response to a Part 18 request, an audiologist’s / medical expert’s line of inquiry, or in witness evidence], he denied that he had any noisy hobbies, saying that on occasion he quietly strummed an acoustic guitar’.
However, information publicly available online showed that Mr. Romaine had ‘lied’.
Videos and photos on social media conveyed his ‘interest in fast motorcycles, fast cars and guitars’. As well as having ridden motorcycles, he was an electric guitarist and lead singer in ‘The 501’s’, a live rock band, which ‘regularly’ performed at pubs, clubs and festivals across the south-east of England. What is more, a website for ‘The 501’s’ claimed that Mr. Romaine ‘shared stages with Slade and Jasper Carrott as a young man and gigged in a folk band’.
In light of the online discovery, Zurich, on behalf of the defunct employer, threatened to apply to strike out Mr. Romaine’s claim. His immediate discontinuance led Zurich to infer that:
‘Mr Romaine had given up as he had been found out’.
Pursuant to CPR 81.10, Zurich sought to find Mr. Romaine in civil contempt of court, by making an application for permission to make a committal application.
At the High Court, in 2018, permission was refused by Mr Justice Goose, on the grounds that it was ‘not in the public interest’.
On appeal to the Court of Appeal, Zurich argued that the High Court judge, having ‘accepted that there was good evidence that Mr Romaine had been dishonest in the presentation of his claim’ had erred in failing to ‘identify any other issue that suggested this application was not in the public interest’.
184 Schmidt JH, Paarup HM, Bælum J. Tinnitus Severity Is Related to the Sound Exposure of Symphony Orchestra Musicians Independently of Hearing Impairment. Ear and Hearing (2018) 40(1):88–97
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By contrast, Mr. Romaine contended that the committal proceedings should not be permitted to go ahead, as he did not personally sign the documents in which the ‘dishonest’ statements appear.
Lord Justice Davis and Lord Justice Haddon-Cave have reserved judgment until a later date.
Counsel for the defendant in the present proceedings, David Callow, explained that claimants making ‘misleading statements’ in civil claims ‘should not go unpunished’:
'This is a clear case of simply deliberate misstatements about this man's non-occupational noise exposure’.
Should this application be successful and Mr. Romaine be found in contempt, he could face up to 2 years in prison. Binding case precedent could deter ‘dishonest’ claimants from bringing fraudulent claims in future.
Mr. Romaine admits that he may have been ill-advised in dropping his claim.
£550,000 Quantum Ruling in Military Deafness Case: Inglis v Ministry of Defence [2019] EWHC 1153 (QB) (BCDN Edition 273)
In edition 265 of BC Disease News (here), we reported that 39-year-old, ex-Royal Marines Platoon Weapons Instructor, Alistair Inglis, had reached an agreement with the Ministry of Defence (MoD), in respect of liability in a military deafness claim (noise-induced hearing loss and tinnitus).
The claimant had been ‘exposed to noise from thousands of rounds of ammunition, thunder flash stun grenades, helicopters and other aircraft and explosive devices’.
At the time, we publicised that issues had been resolved ‘80:20 in the claimant's favour’, which meant that the court would no longer rule on the issue of when military personnel are owed a duty of care, i.e. whether ‘combat activity’ should be immune from legal action.
However, it was still necessary for Mr. Peter Marquand, sitting as a Deputy High Court Judge, to determine a suitable award of damages. When we first reported on the facts of the Inglis case, in a January edition of BCDN (here), it was disclosed that the claimant was seeking damages of £1,275,899, in his schedule of loss.
In view of the fact that the top Judicial College (JC) Guidelines (14th edition) bracket, labelled ‘Severe tinnitus and hearing loss’, provides for general damages up to £39,940 (with the 10% uplift), the claim was predominantly made up of special damages.
The claimant was relatively young and asserted that ‘problems he had experienced with his hearing’ had forced him out of a ‘lucrative line of work’, including the right to receive a full pension (after 22 years of service):
‘[It was] highly unlikely that [Mr. Inglis] would have abandoned his successful military career and those mid-term financial rewards had it not been for his noise-induced hearing problems’.
By contrast, the defendant employer submitted that that, having voluntarily discharged himself, the claimant was still ‘fit for all duties’, with ‘no prospect of being medically discharged’. Thus, there could be no award for future loss of earnings.
In any event, according to the defendant’s witness, it was ‘likely that [Mr. Inglis] would have been offered employment in a specialisation with reduced noise exposure’, had he maintained his role. His subsequent role, in maritime security, was not only ‘an occupation that involves exposure to gunfire’, but also paid him ‘considerably more’. His post-civilian salary (his current Health and Safety Office role) was calculated to be ‘broadly similar’ to his earnings ‘had he not suffered noise-induced hearing loss’.
Much of the High Court judgment, handed down this week, was purely factual – we will therefore only consider the parts of the judgment which concerned contentious legal arguments.
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Why Did the Claimant Leave the Royal Marines?
On the balance of probabilities and resolving the issues discussed above, Mr. Marquand accepted the claimant’s assertion that he left the Royal Marines as a result of his hearing loss. For completeness, see paragraphs 89 and 90 of the High Court judgment on the claimant’s motivations for ‘voluntarily’ discharging himself:
‘As a Royal Marine he was earning £26,000 per annum net but in maritime security he earned in the region of £40,000 a year net at a time with his wife was not working. Whilst the popularity of moving from the Royal Marines to maritime security at the time may raise a suspicion that an individual's motives were financial, on the basis of the Claimant's evidence, which I have already said I accept, it was not the primary motivation or reason in the case of this Claimant ... the Claimant was concerned that his hearing would deteriorate, given what had been told and experienced. The Claimant would have had to weigh up the loss of clear career progression within the Royal Marines, the loss of his potential pension, which I accept he was aware of in general terms and the potential of continued hearing damage by continued noise exposure and the possibility of a medical discharge. Whilst I accept ... that there was career progression within maritime security, I do not accept this is in any way comparable to the career progression within the Royal Marines. There is no evidence that the Claimant was in an immediately precarious financial position and therefore needed to leave the Royal Marines in order to obtain an immediately increased income. The fact that the Claimant chose to go to a more precarious employment supports the conclusion that his primary motivation was to avoid continued damage to his hearing.
I accept the evidence that there was a possibility of the Claimant being redeployed within the Royal Marines in a job that would have had less exposure to damaging noise. However, the Royal Marines were fully staffed at that time and it is unlikely that such a job would have been available for the Claimant, although on the evidence it was a possibility. However, what is relevant is the Claimant's perception of his own position. It is of particular relevance that despite being told to reduce his exposure to noise by medical officers or by that information being sent to his medical officers, there is no evidence that steps were taken to discuss this with the Claimant or to reduce his exposure to noise ... The Claimant was aware of others who had suffered injury, albeit of a different nature and degree, who had not been redeployed. I accept that the Claimant had real fears that he was at risk of a medical discharge’.
Was the Claimant ‘Disabled’, within the Meaning of the Ogden Tables?
When assessing lump sum future loss awards, it is necessary to establish the multiplicand (the annual shortfall in earnings) and the multiplier (a reflection of the Claimant's future years in employment).
The multiplier is affected, at least in-part, by the question of whether the claimant is disabled or not. There was a discrepancy over whether the claimant met the criteria, found in the Ogden Tables and in s.6 of the Equality Act 2010.
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Ultimately, the Judge favoured claimant counsel’s contention that the claimant was ‘disabled’, reasoning, at paragraphs 161 to 163:
‘There is no dispute that the Claimant meets the first limb of the test for disability as his hearing loss is permanent ... Even with his hearing aids he has difficulty in his work environment hearing conversations in meetings, speaking on the telephone and in meetings outside including when working on-site. Without his hearing aids those effects would be worse, although not by much as there is not a significant improvement according to the evidence, which I have already accepted. Those are adverse effects which impact on his ability to carry out his normal day-to-day activities, especially in his work place. Some impacts may be trivial on their own, such as not hearing the oven timer or a person speaking from another room at home, however, taking all of the effects together, as per the Equality Act Guidance, I am satisfied the impact of the Claimant's disability is more than trivial and substantially limits his ability to carry out normal day-to-day activities.
The issue in the third limb of the test is not the amount of work that the Claimant can undertake but the "kind of work". On the basis of the agreed expert evidence there is a limitation on the Claimant in the kind of work that he can undertake by virtue of needing to minimise background noise.
Accordingly, my conclusion is that the Claimant's hearing loss and the effect of that on him means that he meets the definition of disability within the Ogden Tables’.
Seeing that the Claimant was ‘Disabled’, was a Smith v Manchester186 Award Preferential to Ogden?
As an alternative to the conventional multiplier and multiplicand approach, another method is to award a lump sum for a handicap in the labour market, otherwise known as a Smith v Manchester award.
On this issue, defendant counsel requested that Mr. Marquand follow the approach taken in Billett v Ministry of Defence [2005] EWCA Civ 773, in which the non-freezing cold injury (NFCI) claimant was ‘only just’ disabled. In that instance, Jackson LJ criticised ‘reduction factor’ calculations (accounting for disability as a contingency), using Tables A – D, as being:
‘... no more scientific than the broad-brush judgement which the court makes when carrying out a Smith v Manchester assessment’.
In Inglis, however, the High Court Judge concluded that this was not an appropriate (‘minimal impact’ disability) case for a Smith v Manchester award:
‘The uncertainties are not so many as to preclude the multiplier/multiplicand method. The Claimant's injury has a more than minimal impact on his work and the evidence is available to determine an adjustment to the RF without making a broad judgment. Future loss of earnings can be calculated on the conventional multiplier/multiplicand method’.
A figure of £257,518 for future loss of earnings was awarded, based on a ‘reduction factor’ of 0.7.
What about Pain, Suffering and Loss of Amenity?
In regards to general damages, again, Mr. Marquand preferred the submissions of claimant counsel, who argued that the appropriate figure should ‘straddle’ categories 5 (B)(d)(i) and d(ii) of the JC Guidelines (‘Partial Hearing Loss or/and Tinnitus’).
The claimant’s average estimated NIHL, across 1, 2, and 4 kHz, was 16 dB and 17.7 dB, in the right and left ear, respectively. Further, his need for hearing aids had been advanced by around 30 years.
As such, the High Court Judge made an award of £25,000, offering the following justification:
186 (1974) 17 KIR 1.
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‘The Claimant's hearing is affected in social situations, but this is improved by wearing hearing aids. The impact of his hearing loss is more significant in his working life and is not improved significantly by hearing aids. The impact of noise damage on his hearing was first identified in 2006 when the Claimant was in his mid-20s and he now has the hearing of a 70-year-old. His tinnitus affects his ability to sleep and is intrusive although improved by the hearing aids and may be described as moderate’.
The End Result
Quantum was agreed in full, per the table below (subject to an interest calculation and a further 20% reduction).
12 King’s Bench Walk Chambers revealed that the final total award was £545,766.187
The defendant applied for permission to appeal on both factual and legal grounds, but the application was unsuccessful.
Full text judgment can be accessed here.
Quality of Audiologists
As an aside, it is worthwhile to note that during court discussion on the extent of the claimant’s hearing loss, Professor Moore (for the claimant) was preferred to Mr. Byrom (for the defendant), in respect of audiological evidence adduced. This ultimately led to the Court finding that the claimant would benefit from hearing aids. Mr. Marquand referred to Mr. Byrom as being ‘defensive and on occasion flippant’. Whereas, the Judge praised Professor Moore’s expertise on ‘the intelligibility of speech and the design and efficacy of hearing aids’, which were central issues arising in Inglis.
The incongruity of expert opinion between efficacy of hearing aids and intelligibility of speech in background noise (speech intelligibility) will undoubtedly continue into subsequent NIHL decisions.
187 Harry Steinberg QC, ‘Former Royal Marine represented by Harry Steinberg QC is awarded over £500,000 for noise-induced hearing loss’ (8 May 2019 12 KBW)
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Insurer Edges Closer Towards Committal Proceedings Against Dishonest NIHL Claimant: Zurich Insurance Plc v Romaine [2019] EWCA Civ 851 (BCDN Edition 275)
‘It should be emphasised that in litigation of this type insurers are particularly vulnerable to fraudulent claims. NIHL claims often concern issues or allegations of historic exposure and potential non-occupational noise exposure over a long intervening period, and entail long-tail insurance claims where the insured and/or the relevant records no longer exist. Insurers of NIHL claims are, therefore, particularly dependent on the veracity of claimants, both as to occupational and non-occupational causes. The current case is a paradigm example of the problem with the insured company having ceased to exist some 30 years ago’.
In edition 270 of BC Disease News (here), we reported that Lord Justice Davis and Lord Justice Haddon-Cave had reserved judgment on an appeal of an employers’ liability (EL) insurer’s application for permission to make a committal application against a noise-induced hearing loss claimant, who discontinued his claim after an ‘intelligence report’ called into question the honesty of his pleadings.
This week, judgment of the Court of Appeal was handed down.
Facts of the Claim Revisited
Zurich Insurance Plc v Romaine [2019] EWCA Civ 851 regarded a £5,000 occupational deafness claim, allegedly arising out of the claimant's employment as a fridge engineer, from 1978 to 1985.
‘... he denied that he had any noisy hobbies [when interviewed by Mr Hugh Wheatley, the medical expert]’. In Part 18 replies and a witness statement, also accompanied by Statements of Truth, he rebuffed suggestions that he was a professional singer, or a motorcyclist and stated that he only ever played the acoustic guitar for ‘soft music ... on a very rare occasion’.
In actual fact, ‘extensive investigations’ revealed that the claimant was an avid motorcyclist and an electric guitarist and lead singer in ‘The 501’s’, a live rock band, which ‘regularly’ performed at pubs, clubs and festivals across the south-east of England.
Considering this to be ‘a clear case of simply deliberate misstatements about this man's non-occupational noise exposure’, the defunct employer’s insurer threatened to strike out the claim and an immediate discontinuance ensued.
Subsequently, Zurich made a CPR 81.14 application for permission to make a committal application, as was necessitated by CPR 81.18(3), on the basis that proceedings for Contempt of Court may be brought against a person that makes or causes to be made a false statement in a document verified by a statement of truth without an honest belief in its truth – see CPR 32.14 and CPR 81.17.
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However, the High Court refused the application:
‘Whilst there is good evidence of false statements being made deliberately, the documents upon which the Statement of Truth appeared were not signed by the Defendant. This is not a sufficiently strong case bearing in mind the need for great caution before granting permission.
Although it is in the public interest that dishonesty in litigation is identified publically, it is not in the public interest that committal proceedings be brought in the circumstances of this case, where the Defendant discontinued his claim at a relatively early stage of the proceedings’.
An appeal was launched with the permission of Lord Justice McCombe.
Having ‘accepted that there was good evidence that Mr Romaine had been dishonest in the presentation of his claim’, the appellant insurer argued that Mr Justice Goose had erred in failing to find that its ‘application was not in the public interest’.
The Decision on Appeal
Haddon-Cave LJ, with whom Davis LJ agreed, allowed the appeal, finding in favour of the defendant on 3 separate grounds.
‘First, the Judge [Goose J] took into account an irrelevant matter, namely the absence of any warning given to the Respondent that if he brought a claim for personal injury for hearing loss based on false statements, he ran the risk of committal proceedings’.
Although the absence of a warning may be relevant in some cases, it is difficult for a personal injury claimant to show that they have suffered prejudice if they themselves have are responsible for bringing the fraudulent claim.
‘Second, the Judge failed to take into account a relevant matter, namely the mischief that early discontinuance represents in the hands of unscrupulous claimants and lawyers who engage in bringing false insurance claims’.
Labouring this point further, he contextualised insurance fraud within a deeper discussion on the post-April 2013 costs implications that burden defendant employers and insurers:
‘It is clear that the modus operandi of some of those involved in fraudulent insurance claims has been to issue tranches of deliberately low-value claims (sometimes on an industrial scale) for e.g. whiplash, slips and trips etc and when confronted with resistance or evidence of falsity, simply then to drop those particular claims, in anticipation that it would probably not be worth the candle for insurers to pursue the matter further, particularly since recovery of costs can itself be time-consuming and costly and nominal claimants may be impecunious. The problem has become even more acute in recent times because of one-way cost shifting (“QOCS”) and the costs of proving “fundamental dishonesty” under CPR 44.16 (and c.f. section 57 of Criminal Justice and Court Act 2015)’.
‘Third, the Judge erred and was wrong to conclude that the proposed committal proceedings would not be proportionate’.
Thus, the Court of Appeal judges were able to intervene and ‘re-make’ the original, ‘flawed’ decision of Goose J. It was in ‘the public interest’ to do so, not just in this isolated claim, but also in ongoing and future examples of low- value insurance fraud:
‘... the message needs to go out to those who might be tempted to bring - or lend their names to - fraudulent claims: that dishonest claimants cannot avoid being liable to committal proceedings merely by discontinuing their original fraudulent claim’.
Davis LJ noted that the substantive hearing will likely test the claimant’s contention that he was ‘at all material times unaware of what was being said or written by his then solicitors’, Asons.
Full text judgment can be accessed here.
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How Accurate Are ‘Speech Communication Method’-Generated Noise Levels? (BCDN Edition 280)
In April 2019, the results of a Health and Safety Executive (HSE)-funded study were published in the International Journal of Audiology.
The research paper, ‘A simple method to estimate noise levels in the workplace based on self-reported speech communication effort in noise’188 was co-authored by Professor of Audiology, Mark Lutman.
Of course, the University of Southampton Professor is widely renowned for his significant contribution to the ‘Guidelines on the diagnosis of noise-induced hearing loss for medicolegal purposes’ (Coles Lutman Buffin Guidelines), in 2000, and the ‘Guidelines for quantification of noise-induced hearing loss in a medicolegal context’ (Lutman Coles Buffin Guidelines), in 2015.
In his latest study, Lutman et al., identified that objective noise level data, recorded with sound level meters and personal dosimetry, is ‘seldom’ available in research studies or in personal injury claims. This places greater reliance on subjective, self-reported noise level data, which, at least in theory, does ‘not allow for accurate assessment of noise levels and cumulative noise exposure’.
The ‘speech communication method’ has been used, in past research, to estimate retrospective occupational noise levels. This technique involves participants describing the vocal effort required to communicate with a person at a typical conversational distance (1.2 metres) in a given occupational setting. Noise levels are then assigned to descriptions of communication ability.
As a result, the purpose of the 2019 study was to evaluate whether the ‘speech communication method’ provided noise levels that were as valid as objectively measured noise levels.
To do so, the study authors observed a group of participants, between the ages of 16 and 25 years, all of whom were exposed to occupational noise levels in excess of 85 dB(A) for at least 1-hour per day, in the course of the following job roles: • Pottery manufacturing; • Fettling; • Automotive assembly; • Paint shop work; • Shot blasting; • Welding; • Metal working; • Metal casting; • Food processing; • Window frame manufacturing; • Hydraulic pressing; • Petrochemical maintenance; • Pallet loading; • Pharmaceutical manufacturing; • Turbine engine manufacturing; and • Paint manufacturing.
Those with pre-existing hearing threshold levels above 30 dB, a sign of pathological hearing loss, were excluded from the study.
188 Ferguson MA et al., A simple method to estimate noise levels in the workplace based on self-reported speech communication effort in noise. Int J Audiol. 2019 Jul;58(7):450-453.
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The participants were asked to rate the vocal effort required to maintain a conversation with a colleague, who was facing them at a 1.2 metre distance, above a normal level [<81 dB(A)]: • Raised voice [equating to 87 dB(A)]; • Very loud voice [equating to 93 dB(A)]; or • Shouting [equating to 99 dB(A)].
This process was repeated for every main task within each workplace, where neither person had worn hearing protection, where the listener did not have a hearing impairment themselves, and where normal gesturing was used. Only speech communication abilities relating to current employment were compared with objectively measured noise levels. There were 168 self-reports in total.
Meanwhile, objective continuous noise levels [Leq dB(A)] for each working task were calculated with calibrated personal noise dosimetry badges, worn on the tops of the participants’ shoulders. There were 134 tasks performed in current workplaces, meaning that the 34 additional self-reports represented instances where participants worked on the same task in the same area of the workplace, i.e. they were duplicates.
When the objective and subjective measurements were compared, there was a symmetrical distribution of discrepancy, meaning that around 50% of the participants’ self-reports were overestimations of dosimetry and 50% were underestimations. Symmetrical distribution typically signifies a lack of bias.
What is more, 91% of the study group reported noise levels within ±6 dB of objectively measured levels and, of these participants, 56% reported noise levels within ±3 dB. This suggests that subjectively reported noise levels predicted actual noise levels with ‘good accuracy’.
In the remaining 9% of study group participants, i.e. those who provided estimated noise levels outside of dosimetry by more than ±6 dB, 6 individuals reported that they did not need to use a raised voice for tasks measuring up to 96 dB(A) – a ‘substantial underestimation’.
Nevertheless, 96% of the study group reported having to use a very loud voice to converse, inferring noise levels of 93 dB(A). In these cases, the mean difference between reported and measured noise levels was less than 3.2 dB. The authors summarised the key findings as follows:
‘The results show that the method provides noise level estimates having a high probability (>90%) of being within 6 dB(A) of the actual noise level occurring within the workplace. Where noise levels are measured at ≤93 dB(A) the correspondence between estimated and measured noise levels is likely to be within 3 dB. Therefore, participants who reported the need to use a raised voice to hold a conversation with a colleague in the workplace at 1.2m away, which equates to 87 dB(A) on the speech communication table, were highly likely to be working in levels of noise exceeding 81 dB(A). This is above the lower exposure action value of 80 dB(A) in the CNWR, above which an employer must measure noise levels, then monitor and identify risks hearing of employees. Those who reported needing to use a very loud voice (corresponding to 93 dB(A)) would have a high probability of working in noise at or above the second action level of 85 dB(A). At this level employers must ensure that hearing protection is worn and reduce noise levels at source where possible’.
How are the study results likely to impact upon noise-induced hearing loss claims? The authors went on to theorise that:
‘Employee report of required speech communication effort in noise can be an effective method of retrospectively estimating noise levels within the workplace for use in retrospective epidemiological research. This may also be used for other studies where there is no access to dosimetry or formal noise surveys, as well as in medicolegal work where unbiased reports of communication effort are available’.
Although this research may be contextually relevant to medical expert-drafted evidence in NIHL claims, self- reported claimant evidence, in the absence of noise surveys, is arguably most relevant to engineering evidence and discussion on breach of duty.
In the recent case of Mackenzie v Alcoa Manufacturing (GB) Ltd [2019] EWHC 149 (QB) (reported here), the High Court interpreted that the duty of employers to carry out noise assessments, under Regulation 4 of the Noise at Work
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Regulations (1989), was in force from 1970, when industry guidance was prescribed by non-binding publications: Noise and the Worker (1963) and The Code of Practice (1972).
The effect of this was to reverse the burden of proof from the claimant (proving excessive noise exposure) to the defendant (proving under-excessive noise exposure).
Plainly, the issue here, is that an automatic finding on breach, where 1970’s exposure is alleged, may rest on witness recollection of noise exposure that is not just subjective, but also historic. As HHJ Inglis, in the case of Parkes v Meridian Ltd [2007] EWHC B1 (QB), explained:
‘Descriptions of the need to raise voices are very subjective; most of the witnesses are describing events many years ago ... I do not think that the decision on noise levels ... can be affected by the lay witness evidence’.
This position was further cemented by Garnham J, in The National Union of Mineworkers v Organisation Internationale De L'Energie Et Des Mines [2019] EWHC 1359 (Comm), reported here:
‘I have regard to the common human capacity and tendency for a witness genuinely but mistakenly to recollect past events as having actually happened in the way in which the witness now with hindsight believes they would, or indeed should, have happened. In that respect I have also had regard to ...the unreliability of human memory’. In summary, while Lutman et al., may have shown that ‘speech communication method’ is moderately accurate in documenting contemporaneous noise levels, more research is needed to assess whether anecdotal evidence, given decades after an alleged period of excessive noise exposure (or any exposure type for that matter), potentially by elderly claimants, should be admissible in legal practice.
Upcoming Interlocutory Hearing to Consider Strike Out of NIHL Claims Handled by Heptonstalls Solicitors for Payment of Incorrect Court Fee (BCDN Edition 283)
Has claimant industrial disease firm, Heptonstalls Solicitors, been undervaluing claims to pay lesser Court fees? Since 2014, Heptonstalls has issued 80 Claim Forms, in respect of 80 noise-induced hearing loss (NIHL) claims (including several where BC Legal is instructed to act for defendants), and paid £205 on each occasion to do so. For all of these claims, the issued Claim Form specified that the value of claim would not exceed £5,000, which is the upper limit for a £205 Court fee (£3,000 to £5,000).
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However, when supplementary Particulars of Claim were served with proceedings, it became apparent that the claimants were, in fact, seeking damages not exceeding £25,000.
For claims valued between £10,000 and £100,000, the appropriate fee is 5% of the claim. Thus, for all 80 NIHL claims that Heptonstalls was pursuing, the relevant Court fee was £1,250, not £205.
Heptonstalls’ practice of paying the incorrect Court fee, on a repetitive basis, was spotted by District Judge Clarke, at Burnley County Court. The affected claimant has been asked, by way of Court Order (dated 29 August 2019), to show cause as to why their case ought not to be struck out as an abuse of process, pursuant to CPR 3.4(2)(b).
By no later than 28 August 2019, the Heptonstalls partner responsible for supervising the claimant’s claim will file and serve a witness statement explaining ‘why the Claimant failed without an order of the Court to pay the appropriate issue fee’ and why 79 other claimants made the same mistake.
An interlocutory hearing has been listed for Monday 30 September 2019, before Her Honour Judge Beech, at Preston County Court.
The Court has requested that BC Legal nominate a single representative, in respect of each case (in which we are acting), to attend the hearing.
At the hearing, the Heptonstalls partner in attendance will likely be cross-examined upon his or her evidence.
Until the designated Civil Judge for Lancashire has made her decision on whether to strike out the claimant’s claim, all proceedings tied up in this action have been stayed.
What is the likely outcome of the interlocutory hearing?
Defendants have sought to strike-out claims/obtain summary judgment in the following line of cases (with varying levels of success): • Lewis v Ward Hadaway [2015] EWHC 3503 (Ch); • Glenluce Fishing Company Ltd v Watermota Ltd [2016] EWHC 1807 (TCC); • Dixon v Radley House Partnership [2016] EWHC 2511 (TCC); • Wiseman v Marston’s Plc (Sheffield County Court, 2016); • Wells v Wood & Nottinghamshire Council (Lincoln County Court, 2016); • Cross v Black Bull (Doncaster) Limited (Sheffield County Court, 2017); and • Atha & Co Solicitors v Liddle [2018] EWHC 1751.
These decisions have been reported previously in editions 161 (here), 169 (here), 190 (here), 214 (here) and 238 (here) of BC Disease News.
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Most recently, in the case of Atha, Mr. Justice Turner reasoned that:
‘The ordinary and proper use of the court process when providing the statement of value on a claim form involves the recording of the unvarnished truth. Deliberately departing from this ordinary and proper use for tactical reasons, such as removing the risk that the issue fee may subsequently be challenged when costs are being assessed, is significantly different from the ordinary and proper use of the court process’.
However, despite accepting, as other judges had accepted before him, that payment of an incorrect Court fee can amount to an abuse of process, strike out may be ‘too draconian’ (see Cross) and must be balanced against the overriding objective, as was expounded by Mr. Justice Stuart-Smith, in Dixon:
‘... the payment of fees is a matter for the benefit of the Court and is very largely irrelevant to the opposing parties. When asked what actual prejudice their clients had suffered as a result of the asserted underpayment of issue fees in this case, Counsel for [the Defendants] were unable to identify any substantial prejudice at all. The best that could be suggested was that the underpayment of issue fees left the Claimants more money with which to fight the Defendants. In the context of the overall costs of this action, that suggestion pales into insignificance’.
Context is therefore of undoubted importance if a Court is to find that there has been an abuse of its process where incorrect fees have been paid.
In Lewis, the Court ruled that distinguishing abuse of process for this type of breach will depend upon:
‘... the Relationship between the amount of the claim as valued on the Claim Form, the appropriate court fee applicable to that value, and the true value of the claim as it ought to have been known to the relevant solicitor’.
As such, the cumulative effect of Heptonstalls underpaying the Court 80 times in the past 5 years may this time warrant strike-out, where isolated ‘mistakes’ in the past have not.
A Barrister’s Comment on the Issue of Whether Service of Particulars of Claim Always Requires Concurrent Service of a Medical Report? (BCDN Edition 285)
INTRODUCTION
In edition 273 of BC Disease News (here), ‘Leading Barrister’ and Deputy District Judge, Michael Ditchfield, assessed the merit of occupational carpal tunnel syndrome (CTS) claims where the alleged exposure source is computer keyboard use. He did so with reference to the dearth of medical literature on the subject.
This week, Michael delves into a procedural grey area, namely the deadline for serving medical evidence to advance CPR-compliant proceedings.
OPENING COMMENTS ON SERVICE OF CPR-COMPLIANT MEDICAL EVIDENCE
Attempts to wave through the early stages of procedure, in vast quantities of low-value personal injury claims, can throw the occasional curve ball.
In the recent past, claimant industrial disease specialist, Slater and Gordon, attempted to serve computer- generated AMR reports, based on audiometric testing results, with noise-induced hearing loss (NIHL) proceedings.
However, a number of 1st instance Courts ultimately found that AMR reports record the outcome of a test, which cannot not be interrogated in the manner intended by CPR 35 and are therefore not compliant with CPR 35.
Applications were also made by various defendant litigators to strike out these claims on the secondary basis that no (or no valid) medical evidence had been supplied in conjunction with the Particulars of Claim.
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DOES THE CPR PRESCRIBE SERVICE OF THE MEDICAL REPORT WITH PARTICULARS?
CPR 16.4 is the applicable rule, which sets out the contents of Particulars of Claim:
White Book V1 2019 commentary, at paragraph 16.4.1 (below), further elaborates on the purpose that the Particulars of Claim serve. As a matter of preliminary observation, it seems very clear that the function of Particulars is to put forward the factual case which the defendant will have to meet and not to present the completed case on causation.
Nonetheless, it would therefore appear that CPR 16.4(1) imparts no clear duty on claimants to serve a medical report and Particulars of Claim simultaneously – discern use of the conditional tense in White Book commentary: ‘a claimant may ...’
WHAT DOES THE RELEVANT PRACTICE DIRECTION SAY?
In spite of CPR 16 wording, Practice Direction (PD) 16 para 4.3 would conversely appear to mandate service of medical evidence with Particulars where the claimant ‘is relying’ on the evidence of a medical practitioner, while paras 4.1 and 4.2 mandate inclusion of the claimant’s date of birth, details of the injury and schedule of loss.
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Can PD 16 para 4.3 be read or implied in the literal sense that it appears in the text?
‘RELIANCE’ ON MEDICAL EVIDENCE IN INDUSTRIAL DISEASE CLAIMS
In a personal injury action, particularly one where an insidious disease, such as NIHL, can only be verified by objective process, some form of equally objective medical evidence is ultimately required and necessary.
Questions of diagnosis and (more fundamentally) causation, cannot be answered without expert input.
Making a causal link between a condition and an alleged incident, or series of incidents, falls to be determined by an instructed medical expert. As a result, a medical report will typically be required to close the circle between duty, breach and cause.
Having identified why medical reports are essential to establish liability and what they must include to provide assistance with a case, the question of when a report must be served by claimants is up for question.
The typical interpretation of PD 16 para 4.3 is that a medical report, conclusive on diagnosis and prognosis, ‘must’ be served at the same time as the Particulars. It is accepted that a medical report may not draw conclusions on issues of causation or apportionment.
PD 16 para 4.3 is drafted in the present continuous tense (‘... is relying on the evidence of a medical practitioner ...’).
However, in a not unusual hypothetical scenario where a claimant indicates their claim at the very last minute and service imminently follows, limited formal medical evidence may be available or reasonably obtainable at that time.
In these circumstances, it would be inaccurate to say that they ‘are relying’ on medical evidence when the Particulars are served. Instead, it would be more accurate to say that claimant ‘will be relying’ (future continuous tense) on medical evidence in due course, without which their claim will fail. However, PD 16 para 4.3 does not expressly imperativise service of medical evidence which claimants ‘will rely’ on.
Whilst the overriding objective, comprised within CPR 1, impliedly requires parties to enable speedy and proportionate evaluation (potentially settlement) of a claim, it is not immediately obvious that a claimant would be criticised for failing to serve a medical report with the Particulars of Claim?
WHY ELSE MIGHT A CLAIMANT BE EXCUSED FOR FAILING TO SERVE MEDICAL EVIDENCE WITH PARTICULARS?
Other than the often-pressing nature of last minute instructions from the lay client (this cannot always be the excuse) why else might it be perceived that claimants are not under a duty serve medical evidence with Particulars? A claimant may argue that: • There will always be cases, e.g. those necessitating asbestosis diagnoses, where further investigation or additional expert analysis is needed, such that a claimant may be justified, on grounds of proportionality, for not obtaining serial interim reports or serving evidence which does not advance the case; and • The purpose of Part 16, when judged in the round, is to give effect to the next procedural step after a claim is issued; ergo
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• A claim should not be struck out under CPR 3.4(2)(a) [no cause of action/grounds for bringing the claim], nor CPR 3.4(2)(c), in that there has been no abuse of the ‘true wording’ of PD 16 para 4.3, nor an affront to CPR 16.4(1) itself.
HAS THIS RATIONALE BEEN UNEQUIVOCALLY UPHELD BY THE COURTS?
In Williams v Neatman,189 Her Honour Judge Howells began her judgment, as follows:
‘It is, to misquote Jane Austen, a truth almost universally acknowledged amongst personal injury lawyers, that when serving Particulars of Claim for a personal injury claim, a medical report must be served along with it’.
She went on to determine that: • Claimants cannot ‘keep their powder dry’ by hiding or failing to disclose ‘imperfect’ reports [para 29]; • Injuries and their causes ‘do not prove themselves’. A claimant cannot sufficiently prove that they have cut their leg in a fall at work by taking a photograph of their wound. [para 30]; and • Not possessing a medical practitioner report (which a claimant ultimately intends to rely upon), at the point where Particulars are due to be served, is no excuse for failing to serve the report at that point [para 30].
The claimant was therefore found in breach of PD 16 para 4.3, which was further laboured by HHJ Howell’s reasoning, at paragraph 33:
‘... the practice direction does not say, “Well, if you feel like it attach one if you have bothered to get one by then but take as long as you like and serve it when you please….the Defendant won’t mind, and they can probably guess from what you say about the injuries anyway”. Such an interpretation, which is in effect what the Claimant contends for, would run a coach and horses through the overriding objective’.
Months later, in the County Court case of Dalus v Lear Corp & ATV Automotives,190 His Honour Judge Gosnell considered that: • It was perfectly possible not to require a report in every case involving a personal injury. A person bruised in an accident may rely on his own account and a photograph [para 22]; • The fact that a reporting ‘practitioner’ could not be seen as (or was not) a ‘medical expert/practitioner’191 did not mean that a report from such a person would not be caught by PD 16 para 4.3 and service required if that party relied upon it [paras 23-24]; and • The purpose of PD 16 para 4.3 was in fact to require a report coincident with the pleaded case [para 25]:
‘... 4.3 is intended to compel claimants to serve a medical report with the Particulars of Claim (as has been the position for decades) limited to the issue of condition and prognosis. All of the Pre-Action Protocols dealing with personal injury claims (including the Protocol for Disease and Illness claims) envisage the disclosure of at least some expert evidence as part of the protocol prior to the issue of proceedings.
In my view, the purpose of paragraph 4.3 and its predecessors was to compel the Claimant to disclose to the Defendant some corroborative evidence from a doctor or surgeon intended to prove that the Claimant had indeed suffered some injury or illness as a result of the Defendant’s breach of duty (although it was not strictly necessary that the report should deal with causation in claims such as clinical negligence claims)’.
The Judge went on to find that there was a purposive reason to supply medical evidence at the moment that proceedings are served. Further, that if such evidence was provided, even if not by someone who might be properly termed a ‘medical practitioner’, then it must be compliant with CPR 35.
As such, the claimant’s contention that the language of the PD did not seek to preclude a party from supplying reports upon which they may later rely, was rejected.
189 Wrexham County Court. 190 Leeds County Court. 191 In the same way as a physiotherapist was not, nor was a clinical psychologist, but whose reports were capable of supporting certain injuries.
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However, in both Williams and Dalus, counter-applications for relief from sanctions were successful and unless Orders were made.
Was Dalus a Complete Answer to the Question of When Medical Evidence Should Be Served?
Of course, HHJ Gosnell’s interpretation of PD 16 para 4.3, namely that it is intended to compel claimants to serve a medical report with the Particulars of Claim, was theoretical, as the claimants possessed an AMR report.
Further, is it possible that minds were diverted from the ‘true purpose’ of PD 16 para 4.3, as strike out was likely motivated by the auxiliary issue, i.e. the fact that the claimant had adduced evidence that was not compliant with CPR 35?
Another disadvantage of the Dalus decision is its lack of completeness. It leaves undecided whether a claimant, not yet in possession of any medical evidence, is prevented by PD 16 para 4.3 from serving any Particulars of Claim (or at least any compliant document), or susceptible to strike out: reference might be made to the facts and the decision in Hoddinott v Persimmon Homes.192
LATEST HIGH COURT ANALYSIS
In Mark v Universal Coatings & Services Limited & Others,193 the claimant made an application to extend time for service of the Claim Form, the Particulars and the medical report, in respect of a complex silicosis claim where the medical expert report was not yet available.
At 1st instance, His Honour Judge Gargan,194 against the background of an application to strike out, read PD 16 para 4.3 in the following way:
‘... In my judgment a claimant who cannot prove his claim without medical evidence is “relying on the evidence of a medical practitioner” for the purposes of CPR 16 PD 4.3 whether or not a medical report has yet been obtained. Therefore, such a claimant is under an obligation to serve the evidence of a medical practitioner with the Particulars of Claim. To hold otherwise would mean that a claimant in a personal injury action who delayed in obtaining medical evidence would never be required to seek permission to extend the time for service of the medical evidence and/or seek permission from the court to serve the Particulars of Claim without such evidence. There was widespread acceptance among personal injury practitioners that such applications are required. (Indeed, the claimant's solicitors in this case included applications for such extensions when applying to extend the time for service of the Claim form). It is quite clear that medical evidence will be required to establish causation and quantum in this case. Therefore, in my judgment, the claimant was obliged to serve a medical report with the Particulars of Claim unless the court granted an extension of time for such service’.
On this basis, it would appear that as soon as a personal injury claim becomes the subject of intended litigation, the intention of PD 16 para 4.3 is engaged – arguably a more onerous obligation than HHJ Gosnell remarked in Dalus.
Perhaps HHJ Gargan’s reaction to the case was driven, to some extent, by the claimant’s successive attempts to serve the Claim Form without the necessary documents and without, in his view, ‘good reason’?
In combination, Williams, Dalus and Mark (at 1st instance) promote a robust stance against claimant inaction.
On appeal, Mr. Justice Spencer was principally and overwhelmingly concerned with the prospect of the Denton195 principles applying to a situation where there had been a failure to comply with PD 16 para 4.3. Consequently, the bulk of the discussion revolved around whether the relevant PD carried with it sanction, either expressly or impliedly [para 53]:
192 [2007] EWCA Civ 1203. 193 [2018] EWHC 3206. 194 Teesside Combined Court Centre. 195 [2014] EWCA Civ 906.
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‘... in my judgment the failure to serve a medical report and/or a schedule of loss with the Particulars of Claim is not in the same category [as failing to serve and file a notice of appeal in time or failing to serve a respondent's notice, to which the implied relief from sanction doctrine should apply] ... Often, within the context of the particular litigation, this will be a trivial breach because compliance can be achieved with the service of documents which, in the end, are relatively uninformative and do not take the matter any further’.
Despite having been urged against entering into a discussion on the eligibility of an implied sanction to complement breach of PD 16 para 4.3, the High Court Judge identified the difficulty in the universality (‘one size fits all’) of application of the PD as between ‘simple running-down actions and ... a complicated clinical negligence action’. He determined that ‘the provisions ... are in reality intended to be directed towards the former, rather than the latter’.
Having acknowledged that ‘default position’ is that PD 16 para 4.3 does not carry an implied sanction and that there was no ‘abuse of process’ [per CPR 3.4(2)(b)], he set aside the 1st instance Judge’s Order for strike out.196
In summary, the High Court ruling in Mark infers that the judicial treatment of failing to comply with PD 16 para 4.3 should be less forgiving in a low value, straightforward claim, than if the claimant faces the Herculean task of proving causation in a complex disease or clinical action.
In the course of the appeal, no submissions were made regarding the specific PD wording, nor the level of compulsion implied by the Rule, nor the validity of Particulars served without associated documents.
In fact, there was no suggestion that the claimant disputed the requirement for medical evidence to be served with the Particulars and no submissions, akin to those raised by the claimant in Dalus, were made.
With the focus being on the nature of sanction and the availability of relief, Mr. Justice Spencer appears to have relaxed the sting of the Rule and opened the door for dispute regarding service, depending upon whether litigation is ‘simple’ or ‘complex’. A two-tier system may now exist, with low value claims demanding service of medical evidence at the outset and an optional obligation in place for more complex claims.
CONCLUSION
What factors drive interpretation of the CPR, PD’s and White Book commentary?
The case law shows that stringent adherence to semantics and grammatical construction may be excessive and unintended.
Even ‘must’, in the context of PD 16 para 4, does not always mean ‘must’, according to Spencer J [para 54 of Mark]: ‘... the use of the word “must” indicating ... a mandatory provision ... this is a characteristic of the drafting of the CPR and the word “must” is used liberally ... to imply the need to apply for relief from sanction ... where a rule or practice direction contains such wording would ... result in the courts being inundated with applications quite unnecessarily’.
Purpose and proportionality are more certain factors that influence how the Rules and PD’s are intended to be understood.
However, a number of issues remain unanswered or are unclear in existing case law.
The general sense appears to be that some form of medical evidence will be required alongside the particulars where the evidence is to hand and the claimant wishes to rely upon it. This applies even if the report is not from a ‘medical practitioner’, but nonetheless forms the evidential basis for diagnosis and prognosis.
Where medical evidence is not to hand, the claimant can be expected to make an application to extend time for service of the Particulars of Claim with the medical evidence, it seemingly being the case that the former should not be served where the latter is not available.
196 [para 53].
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In all cases, the evidence should be compliant with CPR 35 – that is without question.
There are many pitfalls for the unwary claimant in the early stages of bringing a civil claim. For this very reason, claimants should be monitored closely by defendants, especially where modest value actions are alleged.
Michael Ditchfield Parklane Plowden Chambers Email: [email protected]
NIHL Claims NOT Struck Out, as Heptonstalls Court Fee Saga is Resolved at ‘Show Cause’ Hearing (BCDN Edition 291)
In edition 283 of BC Disease News (here), we reported that a ‘show cause’ hearing had been listed for Monday 30 September 2019, before Her Honour Judge Beech, at Preston County Court.
THE SUBJECT OF DISPUTE
The hearing had been instigated by District Judge Clarke, at Burnley County Court, who noticed that claimant firm, Heptonstalls Solicitors, had repeatedly engaged in the practice of underpaying court fees.
To be precise, Heptonstalls had, on multiple occasions, issued a Claim Form, specifying that the value of the claimant’s claim would not exceed £5,000 and then serve Particulars of Claim with proceedings, indicating that the claimant was, in fact, seeking damages not exceeding £25,000.
Effectively, in ‘more than 80’ noise-induced hearing loss (NIHL) claims, Heptonstalls had paid £205 court fees which, in retrospect, were insufficient – the relevant court fee for a claim valued at £25,000 is £1,250 (5% of the claim value).
Naturally, payment of a lesser court fee, in anticipation of discontinuance, can save claimant law firms a lot of money.
All of these claims were stayed by Court Order (dated 29 July 2019), pending the outcome of the forthcoming interlocutory hearing, in which the affected claimants were required to ‘show cause’ as to why their claims should not be struck out as an abuse of process, under CPR 3.4(2)(b).
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HEPTONSTALLS’ WITNESS STATEMENT
In the interim, Head of Heptonstalls’ Industrial Injury department, Mr. Shane Hensman, filed and served a witness statement, as the solicitor with supervisory conduct of the claims.
The opening section of his statement was an unremitting list of ‘difficulties faced by NIHL claimants ... when attempting to establish their cases and quantify their losses’.
Resting on his 17-years of experience, within which he claims to have handled/supervised ‘several thousand’ NIHL cases, he identified the ‘common features’ of NIHL claims which make assessment of quantum such a ‘difficult’ exercise.
Aside from being ‘very mindful of limitation issues’, he accentuated the ‘fundamental ... feature of NIHL claims ... that the perceived value of a claim may fluctuate significantly between the issue of the claim, and such time as it has been progressed to a relatively advanced stage’.
Seeing that defendants ‘invariably contest the Claim from the outset on all issues of breach of duty, causation and quantum, challenging the items in the Schedule of Loss and seeking additional audiogram tests, sound engineer expert evidence and ENT Consultant expert reports’, he deemed it unfair to expect the ‘precise extent of the Claimant’s “actionable NIHL to be crystallised until the proceedings were at a much more advanced stage’.
Regardless, he explained that it was ‘extremely rare’ for NIHL claims to proceed to trial and would more frequently settle pre-trial for ‘amounts less than £5,000’.
To his knowledge, during the period from 1 January 2014 to 5 September 2019, ‘approximately 1,297 out of 1,307 NIHL claims (so, more than 99%) ... settled for an amount of £5,000 or less ... the average settlement sum achieved across all such NIHL claims was approximately £2,500 to £3,000 ... only around 10 NIHL claims ... settled for amounts greater than £5,000 – and all such settlement amounts were still less than £15,000’.
As such, it was his ‘genuinely-held view’, at the time of issue, that the claimants could ‘legitimately and realistically expect to recover’ less than £5,000 from the defendants. Reflecting this in the Claim Form and satisfying his odd interpretation of CPR 16.3(3) was therefore a means to avoid the ‘significant litigation risk’ of ‘materially’ reducing expected compensation recovery.
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Whereas, counsel-drafted Particulars of Claim, based on the same evidence that was made available to Heptonstalls at issue, should have been appreciated as the claimant ‘putting his or her best foot forward’, he contended.
By his analysis, claimants were ‘open’ to use a ‘comprehensive Schedule of Loss’ to advance the pleaded claim ‘on a hopeful “full liability and full recovery” basis’:
‘I did not, therefore, see anything untoward in a pleaded claim for damages “not exceeding £25,000” being advanced in the Particulars of Claim ... even though I fully expected ... that the figure would come under significant challenge ... and ultimately not represent the true recoverable value of the Claim in practice, as further evidence emerged (especially from additional audiograms) to test the true extent of the Claimant’s condition and prognosis’ He went on to speculate that, ‘if it eventually emerged that the Claimant could expect to recover more than £5,000 then steps would need to be taken, at that stage, to amend the Claim Form and pay the higher applicable Court fee’.
Confronting the abuse of process allegation directly, Mr. Hensman maintained that it ‘was not some artificial construct to permit the Claimants to pay an issuing fee to the Court that was too low’.
Instead, he criticised the lack of commentary on CPR 16.3(3) to explain ‘what is meant by what a claimant “expects to recover”, beyond specific matters in CPR 16.3(6) such as interest, costs or contributory negligence’.
Thus, to provide anything but a ‘genuine pre-estimate’ of the ‘actual value’ of claim, e.g. stating a figure that signified ‘full liability and full recovery’, would have been, in his opinion, ‘detrimental to the claimant’s position’.
Explaining how this approach could possibly be ‘detrimental’, he described the negative consequences of a claimant paying the higher court fee, only to recover £5,000 or less:
‘In such circumstances, there is no way to seek a rebate of such overpayment from the Court, and so there would be a significant shortfall that would have to be met out of the Claimant’s compensation. In a case which ultimately settled for around £3,000 ... this would potentially expose the Claimant to an immediate loss of over a third of his compensation’.
Ordinarily, successful claimants would seek to recover excess court fees from the defendant, but his statement was strongly against the idea of ‘dragging’ claimants into ‘contested costs assessment proceedings’, thereby risking further ‘expense’ and ‘delay’ to the conclusion of proceedings.
Additionally, the ATE insurance (for disbursement costs) argument was made, specifically that insurance premiums typically rise with increasing court fees and would (in post-LASPO claims) also have to be deducted from any compensation recovered by the claimant.
In any event, Mr. Hensman submitted that the claims did not warrant striking out, as they represented ‘valuable causes of action’ and ‘at the very least’, the claimants should be able to ‘achieve a recovery of the amount not exceeding £5,000 for which they have paid their Court fees’.
He went on to state that, since none of the defendants had sought to strike out the claims before the Court intervened, it could not be said that the defendants had ‘suffered prejudice’.
Finally, he concluded that strike out would be a ‘a disproportionate and unjustly severe sanction for the Court to impose’, not less because it would ‘heavily penalise the Claimants personally for doing no more than following their solicitors’ advice’.
‘SHOW CAUSE’ HEARING
The ‘show cause’ hearing was attended by BC Legal’s in-house barrister, Liam Bedford.
He remarked that it was a ‘strange and disjointed affair’, which comprised mostly of ‘discussion’, with ‘no real submissions’ having been made.
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‘The Judge made it plain that she was not going to strike out the claim. She was minded to make an order limiting the Claimant to the value stated on the Claim Form unless an application was made to increase the statement of value in the Claim Form within a period of time’.
In spite of Mr. Hensman’s extensive witness statement, claimant counsel, Ben Williams QC, conceded early on that Heptonstalls’ lesser court fee methodology could not be sustained and was based on an ‘incorrect reading of CPR 16’. However, there was no immediate concession that it amounted to an abuse of process.
HHJ Beech thought it ‘bad practice’ to act as they had and ‘read the JC Guidelines to Mr. Williams QC to explain that the value of claim would always be above £5,000’.
After having been commanded by the designated Civil Judge for Lancashire to take further instructions on conceding abuse, he returned and said the following:
‘Claimants have received external advice and accept that the full value of the claim is the full value they expect to recover, not what they are seeking to recover. They do not accept that the practice was culpable abuse of process’.
The upshot of the hearing and the supplementary Order made is that the claims were not struck out. Instead, it was ordered that claims would be limited to the originally stated value [subject to CPR 16.3(7)], unless the claimants applied to amend their Claim Forms within 28 days, together with payment of the correct court fee.
The costs of any successive amendments are to be borne by the claimants.
What is more, we were awarded £600 to cover the majority of our costs of attendance, which were agreed to be paid by Heptonstalls (as opposed to the claimants themselves), within 28 days.
CONCLUSION
These proceedings are, at the least, proof that Courts in England and Wales are now wise to Heptonstalls’ recent history of underpaying court fees. Abusive or not, claimant firms will have to tread carefully from this point forwards to steer clear of incurring stricter sanctions.
CPR 16.3(3) ‘requires a Claim Form to state the full value of the claim which is being asserted rather than the level of recovery ultimately expected’. This is unmistakeable.
Claimant solicitors cannot rely on years of experience of compromising compensation recovery in pre-trial settlements to deflect from the literal and logical reading of this rule.
Study on the Impact of Tinnitus on Professional Musicians to Begin in December 2019 (BCDN Edition 291)
On 2 October 2019, the British Tinnitus Association (BTA) announced a new partnership with Help Musicians UK (HMUK), after the musicians’ charity was handed a £45,764 grant to launch a ‘pioneering’ investigation into the effects, management and prevention of tinnitus experienced by musicians and music industry professionals in the UK.
The study is due to start in December 2019.
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According to BTA, this is a relationship which has not been ‘rigorously researched’.197
Describing the affiliation between tinnitus and professional musicians as ‘as yet uncharted territory’, BTA Chief Executive, David Stockdale, revealed that:
‘BTA researchers will have access to a pool of HMUK-supported musicians and will collect quantitative and qualitative data, allowing for more in-depth insights than have ever been captured before. Considering everything from genre and frequency of performance, to instrument and the position it’s played in, the findings will pave the way for the broadest understanding of the effects of tinnitus within the UK music sector yet and open doors for effective, targeted support’.
Dr. Georgie Burns-O’Connell, Research Officer at BTA, considers that:
‘The project has the potential to have worldwide influence in establishing an understanding of the impact of tinnitus on musicians. This will ultimately lead to a better understanding, stronger messaging around prevention and management and improved services for musicians living with tinnitus’.198
It is anticipated that study findings will be published in August 2020.
Based on surveys of 692 musicians, conducted by HMUK in 2015, 40.5% of respondents reported living with hearing problems, 75% of whom reported experiencing tinnitus.199
This connection is also confirmed by the academic literature, where researchers have observed increased incidence of hearing loss and tinnitus among symphony orchestra musicians,200 pop, jazz and rock musicians,201 academic music students,202 club employees203 and disc jockeys.204
Tinnitus is a subjective condition, commonly alleged in conjunction with noise-induced hearing loss. The dominant symptom in tinnitus sufferers is the sensation of hearing a sound, e.g. ringing, whooshing, humming, buzzing, etc., in the absence of any external sound.205
197 Nic Wray, ‘Investigating the impact of tinnitus on professional musicians’ (2 October 2019 British Tinnitus Association)
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Noise-induced tinnitus (the most common tinnitus type) is perceived when the inner ear has been impaired.
Cochlear hair cell damage prevents the transmission of electrical signals via the auditory (vestibulocochlear) nerve. When the brain actively ‘seeks out’ failed transmissions, electrical signals can become ‘over-represented’ and this over-representation resembles tinnitus.206
[Source: Wikimedia Commons – Zina Deretsky (23 October 2006): ‘Acoustic radiation’]
Professional musicians can often be exposed to excessive noise levels, putting them at ‘increased risk of hearing damage’, explained HMUK’s Head of Health and Welfare, Joe Hastings.
Looking at the wider consequences of the BTA research project, it is important to reiterate the Court of Appeal judgment in Goldscheider v The Royal Opera House Covent Garden Foundation [2019] EWCA Civ 711, which was reported in edition 271 of BC Disease News (here).
This case was significant, not only because it confirmed that the phenomenon known as ‘acoustic shock’ (also linked with tinnitus) was not limited to ‘white noise’ exposure, common among call centre workers, but also because it allowed an orchestral violist to sue his employer for personal injuries caused by instrumental noise exposure that was not ‘an unwanted secondary by-product of a primary process but the product itself’.
Further, that, had the employer complied with its duty of care to protect the claimant’s health and safety in the course of the rehearsal, in which the injurious exposure took place, there was no evidence to suggest that there would have been ‘an unacceptable reduction (or indeed any reduction at all) in the artistic standards of the Ring Cycle when it came to be performed in public’.
Should Goldscheider remain an unchallenged leading authority in this area, it is possible that more ‘acoustic shock’ and NIHL (with or without tinnitus) claims may be advanced by professional musicians (and other entertainment- based professionals). If so, BTA’s research could provide meaningful insight into the prevalence of tinnitus in the music industry, the existence and extent of which can have a profound effect on the value of occupational deafness claims.
206 ‘Tinnitus’ (NHS Direct Wales)
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London Underground Suspend Industrial Action, as TfL Promise to Take Action on ‘Complex’ Tube Noise Issue (BCDN Edition 292)
In 2018, the BBC used noise meters, supplied by University College London (UCL), to record sound levels at stations in zones 1 and 2 of the London Underground. We reported, in edition 217 of BC Disease News (here), that Dr. Joe Sollini, of UCL's Ear Institute, described tube noise levels as ‘concerning’,207 with 109 dB having been measured between Liverpool Street and Bethnal Green (Central Line) and Camden Town and Euston (Northern Line).208
[Source: Geograph – N. Chadwick (29 May 2018): ‘Central Line at Liverpool Street Station’]
Then, in April 2019, more research on tube noise was published. EAVE, an organisation dedicated to the prevention of avoidable hearing loss, mapped noise levels across the complete tube network (to view the results, click here) and recorded peak noise levels between Canary Wharf and North Greenwich (Northern Line), of 105 dB.209
207 ‘Tube noise levels: London Underground drivers to take action’ (26 September 2019 BBC News)
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EAVE also identified a 5-minute stretch of the Victoria Line, where noise levels average 90 dB, while noise levels at 37 stations frequently reached 85 dB and above.210 Employers are required to provide mandatory hearing protection to employees, when the upper exposure action value [daily/weekly dose of 85 dB(A)] is reached – see Regulation 7(2) of the Control of Noise at Work Regulations (2005).
Tube drivers have complained of a ‘barrage’ of ‘horrendous’ noise, which is ordinarily perceived as either ‘continuous screeching’ (louder where the rail is corrugated211), or ‘the undercarriage being shaken to bits’.
In spite of this, Transport for London (TfL) has long-maintained that the Health and Safety Executive (HSE) guidance supports the assertion that noise exposure on the London metro is ‘highly unlikely to cause long-term hearing damage’212 and aims to keep volumes below an average level of 77 dB.
In June 2019, though, Victoria, Jubilee, Central, Piccadilly, Bakerloo and Northern Line drivers received a ‘broader range of ear protection’,213 somewhat implying the potential existence of an employers’ liability (EL)/public liability (PL) risk.
It is, perhaps, because of this enduring employer-employee disagreement that, on 11 September 2019, the Rail, Maritime and Transport (RMT) union demanded urgent action on tube track noise.
When ‘indefinite’ industrial action was first announced, last month,214 RMT General Secretary criticised TfL for being ‘too slow’ to make progress on noise attenuation:
‘It is appalling that RMT driver members have had to resort to a ballot in order to force London Underground to take the issue of excessive track noise seriously’.
95% of driver members on Jubilee, Central, Northern and Victoria Lines voted in favour of an interruption to normal service,215 which was due to begin at 00:01 hours, on 10 October 2019. This would not have unfolded as a strike, but with temporary speed reduction over 28 sections of track:216 • Between Euston and King’s Cross (Victoria Line); • Between Tottenham Court Road and Holborn (Central Line); • Between Camden Town and Euston (Northern Line); and • Between Green Park and Bond Street (Jubilee Line).
210 Helen Coffey, ‘TUBE STRIKE: DRIVERS TO CUT SPEED BY HALF DUE TO ‘NOISY’ TRACKS, CAUSING TRAVEL CHAOS’ (26 September 2019 The Independent)
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The specific instruction to drive in ‘manual mode’ at 50% of full-speed, was deemed to be an ‘appropriate reduced speed to mitigate the creation of excessive noise and to alleviate the distraction, discomfort and anxiety caused in the affected areas’, for the benefit of both drivers and travelling public alike.217
Why target these 28 specific sections of track?
In order to reduce disturbance for residents who live above the tube network, a unique rail fastening system, called Pandrol Vanguard, was installed at ‘priority sites’218 to isolate vibration and moderate noise emissions.219 The downside to this has been the creation of ‘increased in-carriage noise for both customers and staff’, as verified by Mayor of London, Sadiq Khan.220
Especially disappointing, is that noise transmission has, in fact, worsened for residents ‘in surrounding homes’ – the intended beneficiary of purported technological advancement.221 Pandrol has blamed greater than expected noise levels on ‘increased rail roughness’.
This gave rise to union calls to revert back to old technology, but TfL, instead, commenced new installation of ‘under rail pads’222 to dampen and change the frequency of noise, thereby counteracting the flaws offered up by Pandrol Vanguard.223
Did the industrial action go ahead last week?
Eventually, RMT was able to abandon their ‘go-slow’ policy. ‘At the eleventh hour’, the union was given assurances from TfL, that:224 • It would introduce speed restrictions in multiple locations from 11 October 2019, to mitigate the noise impact; • There will be a programme of increased rail grinding to bring down noise; • It will make available £10 million to cover remedial works; and • Pandrol Vanguard will eventually be removed from all locations.
A TfL Spokesperson subsequently pledged that:
‘The health and safety of our staff and customers is our top priority and we will continue to progress a number of immediate and longer-term plans to help solve this complex issue’.225
If TfL were to take influence from Luis Gomez-Agustina, Acoustics Lecturer at London South Bank University, such longer-term plans could include:
‘... rail lubrication, rail improvement or replacement, improving vibration isolation from wheel and track to the carriage, providing air conditioning to seal carriage windows, improving sound insulation of windows carriage walls, damping vibration of radiating panels of the carriage, and even installing active noise cancelling to eliminate loud difficult to remove squeals or hums’.226
217 ‘Tube drivers to launch industrial action over noise levels’ (26 September 2019 ITV)
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In actual fact, The Standard reported that track lubrication, in Finchley, had successfully lowered noise levels by around 10 dB.227
Mr. Cash, who was recently backed to serve another 5-year term as General Secretary,228 has cautioned TfL that RMT will remain ‘vigilant’, while the agreed programme of action is rolled out.
We will also remain ‘vigilant’ to the emergence of tube drivers bringing NIHL and/or tinnitus claims.
Feature: Why is Tinnitus Playing an Ever-Dominant Role in ‘Common Whiplash’ Claims? (BCDN Edition 293)
INTRODUCTION
Tinnitus is a subjective acoustical phenomenon, which is perceived without having an extrinsic source of sound. It is commonly associated with noise-induced hearing loss (NIHL), i.e. inner ear damage, but the exact cause(s) of tinnitus is unknown.
In recent times, motor insurers have observed an unexpected increase in road-traffic accident (RTA) claims that seek compensation for otologic injury, specifically tinnitus, in addition to conventional soft tissue injuries.
Of course, serious vehicular collisions, which involve complex head trauma or brain injury, are commonly associated with sensorineural damage.
However, an unambiguous tinnitus spike in low-impact, run-of-the-mill whiplash claims begs the question, why was tinnitus seemingly less prevalent in years past?
WHAT IS WHIPLASH?
Crowe first coined the term, ‘whiplash injury’, in 1928.229 In the same decade, Barre and Lieou both referred to tinnitus as being the most frequent symptom in patients presenting with cervicospinal injuries, but the earliest example of this connection dates back to 1843 and Terret.230
Whiplash injuries occur as a result of violent movement of the head with forceful extension (away from the body, i.e. tilting head back and looking to the sky) and flexion (towards the body, i.e. tucking the chin into the chest) of the neck, thereby resulting in cervical spine and soft tissue injuries.
Gay and Abbott (1953) were the first to cite ‘rear end’ RTA as ‘common whiplash injury’.231 Although RTA can, of course, involve ‘lateral’ or ‘front-end’ collisions.
227 Ross Lydall, ‘TfL Tube drivers given ear defenders to block 'screeching' noises from new tracks’ (27 June 2019 The Standard)
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[Source: Geograph – Lewis Clarke (28 August 2012): ‘South Somerset : The A303 & Road Accident’]
WHY DO RTA CAUSE WHIPLASH?
Drivers are legally obliged to wear seat-belts as a safety precaution against the infliction of ‘direct wounds’. However, if a driver has a surprise collision with another vehicle whilst wearing a seat-belt, the energy transmitted and absorbed by the head and neck, on impact, is greatly increased (but less severe if the headrest is adequately positioned). This is because seat-belts limit the movement of the thorax (chest) and therefore increase the extent to which the head can move, in relation to the rest of the body.232
Inertia, experienced by abrupt hyperextension and hyperflexion of the neck, is considered to be the ‘whiplash injury mechanism’.
ARE ‘COMMON WHIPLASH INJURY’ AND TINNITUS LINKED?
Clinical manifestations of whiplash injuries have been termed ‘whiplash-associated disorders’ (WAD). Spitzer et al. (1995) commented that WAD can include auditory disorders, such as tinnitus.233
Around 80% of whiplash victims will recover from their injuries in a matter of months. However, Claussen and Claussen (1995) observed ‘so-called late whiplash injury syndrome’ (LWIS) in 15% to 20% of approximately 200,000 whiplash patients.234 Balla (1980) defined LWIS as ‘a collection of symptoms and disabilities seen more than six months after a neck injury occurring in a motor vehicle accident’.235
Incidentally, the majority of LWIS sufferers complain of ‘cervico-encephalic syndrome’, a post-traumatic syndrome of whiplash, which was heavily linked with tinnitus by Chetana and Claussen (2010).236
232 Boniver R, Temporomandibular Joint Dysfunction in Whiplash Injuries: Association with Tinnitus and Vertigo Intemational Tinnitus Joumal, Vol. 8, No.2, /29-I31 (2002)
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HOW COMMON IS TINNITUS IN WHIPLASH SUFFERERS?
Oosterveld et al. (1991) observed tinnitus in 14% of 262 whiplash patients, who were subjected to ‘trifle-and minor- traumas’.237 Elsewhere, Tranter and Graham (2009), in a later review of oto-vestibular symptoms following whiplash injury, calculated incidence of 10%, further noting that this is open to exaggeration [see 41% tinnitus in Decher (1996)238].239 In spite of this, Rowlands et al. (2009) discovered significantly lower rates of tinnitus among patients with low-grade whiplash injuries.240
HOW COMMON IS WHIPLASH IN TINNITUS SUFFERERS?
Conversely, in a sample of 1,604 Tinnitus Research Initiative (TRI) participants, Kreuzer et al. (2012) identified whiplash-induced tinnitus in only 4.9%, which was described as a ‘small subsample’.241 By contrast, Folmer and Griest (2003), who surveyed tinnitus patients in a Canadian clinic, observed a history of whiplash injury in more than 10%.242
These studies emphasise that the origins of tinnitus are wide-ranging and cannot simply be attached to whiplash injuries without first conducting detailed investigations (e.g. into occupational history/lifestyle, etc.).
HOW MIGHT ‘COMMON WHIPLASH INJURY’ ONSET TINNITUS?
Inertia experienced during a motor accident, as briefly explained above, causes hyperflexion and hyperextension of the neck, which is supported by vertebrae in the cervical spine. Stress endured by this portion of the spine, during a road-traffic collision, can theoretically lead to micro- and macro-traumas of muscles, tendons, intervertebral discs, ligamentous structures and the spinal cord.243
Does the medical literature suggest that musculoskeletal damage of this kind is associated with tinnitus?
As a primary observation, mild whiplash often results in cervical myelopathy (damage to the spinal cord)244 and patients with cervical myelopathy, according to Johansson (2006), have been diagnosed with tinnitus.245
Volle (2000) asserted that increased axial rotation of the upper cervical spine can cause tinnitus.246 The same author published a paper, several years prior, which also conveyed a strong correlation between injuries of the craniocervical joint (CCJ) complex (upper segment of the cervical spine) and tinnitus.247
237 Oosterveld WJ et al., Electronystagmographic findings following cervical whiplash injuries. Acta Otolaryngol. 1991;111(2):201-5.
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What is more, Steilen et al. (2014) discussed that when capsular ligaments (fibrous tissue that strengthens joints) are injured, they become elongated and exhibit laxity and instability. All that may be required is a single macro-trauma, sustained in the course of a whiplash injury. If damage occurs in the cervical spinal region, cervical vertebrae will move excessively. Further, if this occurs in the upper cervical spine (C0-C2), sufferers may report tinnitus.248
Similarly, hyperextension and hyperflexion of the neck has the natural biomechanical consequence of violently opening and closing the jaw. Rapid elongation and compression of the temporomandibular joint (TMJ) may promote tinnitus.249 Kolbinson et al. (1997) commented that TMJ was more prevalent in whiplash victims than in a control group.250
Another physiological pathway to tinnitus was investigated by Kaute (1998), who simply assumed that the irritation and tension of posterior cervical muscles, caused by whiplash, has the propensity to over-stimulate the vestibular nuclei in the brainstem; an origin of idiopathic tinnitus. As a result, he championed atlas therapy as a means to normalise the flow of information sent to the brainstem and overcome tinnitus.251
Elsewhere, Bhatt and de Carpentier (2012), in a novel case study, analysed the presence of bilateral tinnitus, triggered by whiplash-induced hyperextension neck injury in a low-speed road traffic accident.252 When asked to describe the tinnitus, the 70-year-old patient compared the sensation to orchestral music, which was familiar to him (‘Chorus of the Hebrew Slaves’, from the opera Nabucco, by Verdi). The study authors concluded that this was the first published case of musical hallucination precipitated by whiplash injury – a previously unreported phenomenon. Is this an under-reported condition?
Perhaps the most relevant research on this topic was undertaken by Claussen and Constantinescu (1995). 73 out of 91 LWIS cases, without contact trauma (i.e. no direct knock of the head and/or neck against a hard surface inside of the car), were affected by ‘subjective tinnitus’. The authors went on to affirm that ‘even the simple, non- contact whiplash injury can be the cause of long lasting, chronic poly-sensorial disturbances’, which closely intertwine with tinnitus.253 They also recognised ‘degenerative cervico-spinal injury syndrome’ as an instigating factor, as well as vascular disturbances in the posterior cranial fossa, due to a narrowing of the vertebral artery in the cervical spinal region.
All things considered, there would appear to be some clinical validation, based on how musculoskeletal changes interact with brain functioning, that tinnitus could be characteristic of ‘common whiplash injury’, e.g. low-impact motor accidents. Indeed, neck pain is the most common symptom described after whiplash injury mechanisms and is reported in 88% to 100% of cases, depending on the study, say Vibert and Häusler (2003).254
However, tinnitus is a subjective condition, which makes true prevalence so very difficult to accurately estimate – hence the variation across a spectrum of research papers. One can only speculate.
248 Steilen D et al., Chronic Neck Pain: Making the Connection Between Capsular Ligament Laxity and Cervical Instability. The Open Orthopaedics Journal, 2014, 8, 326-345.
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HOW GENUINE IS THE TINNITUS SPIKE IN RTA CLAIMS?
Could it be the case, instead, that claimant personal injury solicitors are, in fact, encouraging claimants to exaggerate their ‘common whiplash injury’ symptoms, in order to inflate medical expert fees and schedules of loss?
With an increased small claims limit (up to £5,000) and whiplash tariff system looming, monosymptomatic (i.e. mild soft-tissue damage only) RTA claims allocated to this broadened track may no longer be profitable for claimant legal representatives, in the absence of costs recovery.
By tying in other co-morbidities, such as tinnitus, the claim value can be increased to fast track levels and beyond. Damages exceeding £25,000 would fall outside of the fixed costs regime, at least until the Government decides to institute Sir Rupert Jackson’s proposals.
For example, see Quittance Legal Service’s article on a £16,574 order for damages, awarded to a low-impact whiplash claimant, who rated his tinnitus as ‘4 on a scale of 1 to 10, 10 being the most severe’.255
Nonetheless, this year has seen a surge in findings of ‘fundamental dishonesty’, under s.57 of the Criminal Justice and Courts Act 2015, and an increased appetite for insurers to commence civil contempt proceedings. The legal system is finally getting to grips with fraudulent claims, yielding dismissed claims, recovery of legal fees through qualified-one-way costs shifting (QOCS) disapplication, orders for wasted costs and punitive fines.
Claimant solicitors should therefore be wise to a higher risk of professional negligence and decreased success in advancing standard RTA claims, if an additional tinnitus element is anything but wholly authentic. ‘Exaggeration’ alone can render a claimant ‘fundamentally dishonest’ and invalidate the claim in its entirety – read our precis of LOCOG v Sinfield [2018] EWHC 51 (QB) (here).
Stuart Bacon, Head of BC Legal’s Southend Office, gives his view, below:
‘Whether genuinely or otherwise, it seems tinnitus is going to be an increasingly common feature of soft tissue RTA claims.
General damages for tinnitus are not insignificant:
Note the dramatic difference in general damages between, “slight” and “moderate tinnitus”.
As disease lawyers we are more than familiar with arguments over the grading of tinnitus and the range of expert medical opinion that commonly exists in this regard. Will we now see these arguments and the expense of such in RTA claims?
255 Gaynor Haliday, £16,574 awarded to claimant suffering from tinnitus’ (Quittance Legal Services)
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I question whether tinnitus should, in a medico-legal context, be diagnosed and causally attributed by experts typically instructed in RTA claims i.e. GPs, A&E Specialists and Orthopaedic surgeons. If not, are we going to start seeing the complex causation and grading arguments from NIHL claims in RTA claims? Will the Courts entertain expensive expert ENT evidence?
On one hand I feel the Courts will do all they can to deter ENT evidence in RTA claims but on the other, I can see an approach similar to that seen in NIHL claims, which regularly sees both parties armed with their own expert ENT evidence. It is now judicially accepted that, despite their modest value, NIHL claims involve complex issues of causation to the extent that Defendant ENT evidence is considered appropriate in all but the most straightforward of claims.
Insurers and the Courts will be far from keen to see ENT evidence in RTA claims, but if claims are made, which they now appear to be in increasing numbers, both are going to have to decide how to proceed.
To simply pay the claims will require insurers to accept diagnoses from medico-legal experts who have little to no clinical experience of diagnosis and quantification of tinnitus and pay damages on top of awards for soft tissue injuries. With general damages for tinnitus starting at £6,140, this is likely to be an unattractive option and perhaps justification of the ~£1,000 spend on expert ENT evidence.
However, as we have seen in NIHL claims, there is likely to be a range of expert opinion on causation and grading of tinnitus so the ~£1,000 could well become ~£2,000 if two ENT experts provide evidence.
For insurers, tinnitus will certainly add an unwelcome dimension, complexity and costly element to RTA claims at a time when such claims are finally becoming more manageable.
In my view, a ‘head in the sand’ approach on this has the potential to lead to unhelpful and costly precedent and insurers would be wise to bring in the expertise of their NIHL claims handers to work with their RTA handlers.
If these claims litigate and at least until the Courts provide some clarity on this issue, I think it would be beneficial to have disease lawyers involved. Naturally, BC Legal will be more than happy to assist’.
Feature: Allegations of Historic Noise Exposure Devoid of Noise Surveys: Mackenzie v Alcoa Manufacturing (Gb) Ltd [2019] EWCA Civ 2110 (BCDN Edition 299)
INTRODUCTION
One of the most eagerly anticipated judgments of 2019 was the appeal of Mackenzie v Alcoa Manufacturing (GB) Ltd [2019] EWHC 149 (QB), on breach of duty in noise-induced hearing loss (NIHL) claims.
For detailed analysis on the High Court ruling, read our article, which featured in edition 261 of BC Disease News (here).
FACTS OF THE CASE
An employers’ liability (EL) claim was brought against a former employer and the occupier of a factory (the defendant in the present case).
73-year-old, Mr. Mackenzie advanced his case on the basis that he had been exposed to injurious noise levels, in the course of his employment as an apprentice electrician, between 1963 and 1976, when he installed, maintained and repaired machines for an aluminium smelting business.
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Essentially, the claimant’s Particulars of Claim alleged that his NIHL had been caused by the negligence and/or breach of statutory duty of both defendants. In particular, the failure to assess noise levels by undertaking noise surveys.
Witness evidence testified that the claimant ‘never worked more than a few feet’ from machinery, which sometimes had to be switched on to find a fault. Jobs varied in length, some taking ‘minutes’ and others lasting ‘days’.
Describing noise levels, the claimant asserted that ‘it was necessary to shout to communicate’ with colleagues in close proximity.
It was also pleaded that no hearing protection had been provided and there had been no forewarning about the risks associated with exposure to excessive noise.
1st INSTANCE DECISION
At the 1st instance trial of liability, in November 2017, His Honour Judge Vosper QC concluded that, although the defendant had not presented physical copies of noise surveys undertaken, it was ‘not possible to make a finding that ... [the defendant was] ... in breach of duty in failing to carry out noise surveys’.
Further, the judge relied on the report of acoustic engineer, Mr. Kevin Worthington, who estimated the claimant’s noise exposure by extrapolating noise levels collected in 1989, by a ‘reputable noise and vibration consultancy’ at a comparable industrial premises. Mr. Worthington remarked that it would be ‘very difficult’ to substantiate a claim on engineering evidence that the noise levels were injurious:
‘... it is not possible to demonstrate, on the balance of probability, that his average daily noise exposure level would have reached or exceeded 90dB(A) during these period of employment’.
Conducting a balancing of reliability exercise, HHJ Vosper preferred the evidence adduced by the jointly- instructed expert, fearing that the claimant may have ‘likely exaggerated’ his exposure:
‘... the Claimant's evidence could not be regarded as sufficiently precise for me to reject the engineering evidence in favour of it. That is not to criticise the Claimant. It is simply unrealistic for him to be able to remember in detail the events of more than 50 years ago’.
As such, the claimant was unsuccessful in proving, at Swansea County Court, that he had been tortiously exposed to noise by either defendant.
JUDGMENT OF THE HIGH COURT
Subsequently, the claimant appealed against the dismissal of his claim against the factory occupier (the defendant), which formed the basis of our case summary in edition 261 of BCDN.
The main thrust of the claimant’s argument, on appeal, was that the 1st instance judge had erred in having distinguished the present case from Court of Appeal’s decision in Keefe v Isle of Man Steam Packet Company [2010] EWCA Civ 683, on assessment of the defendant’s purported breach of duty.
Also a NIHL claim, Keefe regarded a 20-year period of occupational (and excessive) noise exposure, beginning in 1973, in response to which the defendant employer admitted that no noise measurements had been taken.
In such circumstances (i.e. where there has been an open admission that the defendant failed to assess noise levels), which were especially ‘unusual’ because there was no engineering evidence to refer to, Lord Justice Longmore advised, at paragraph 19 of his judgment, that:
‘If it is a defendant's duty to measure noise levels in places where his employees work and he does not do so, it hardly lies in his mouth to assert that the noise levels were not in fact excessive ... the court should judge a claimant's evidence benevolently and the defendant’s evidence critically … [A] defendant who has, in breach of duty, made it difficult or impossible for a claimant to adduce relevant evidence must run the risk of adverse factual findings. To my mind this is just such a case’.
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At the High Court, last year, Mr. Justice Garnham allowed the claimant’s appeal, finding that HHJ Vosper had been wrong to distinguish Keefe on the facts.
In so doing, the judge showed suspicion towards the defendant’s failure to produce any noise surveys, despite the development of ‘relevant regulatory requirements over time’. Even though there had been no direct confession that surveys had not been undertaken, passage of time, in Garnham J’s view, might only explain away the absence of the oldest documents in the defendant’s possession.
Moreover, it was perceived to be irrelevant that the Noise at Work Regulations 1989 applied in Keefe, but had not yet been drafted when Mr. Mackenzie’s excessive noise exposure was allegedly taking place.
In addition, the High Court Judge rejected the single-joint expert’s report as a factor capable of differentiating Mackenzie from Keefe. Only if engineering evidence ‘provides positive evidence as to the level of noise to which workers were in fact exposed at the relevant time and the relevant premises’, Garnham J contended, could the absence of noise surveys be rendered of ‘little significance’.
Having determined that Keefe should have been followed at the original trial, the Judge reasoned that:
‘A benevolent interpretation of the claimant's evidence would have ... [found that] ... on occasions at least, the noise level would reach or exceeded 90dBA and that the expert evidence was unable to disprove that this could not have been the cause of his hearing loss’.
THE COURT OF APPEAL RULING
Understandably disappointed with the High Court decision, the defendant appealed to the Court of Appeal, on the basis that the facts of Mackenzie constituted clear grounds to avoid a Keefe adverse inference.
The case was heard by Lord Justices Bean, Baker and Dingemans.
Existence of Noise Surveys?
Handing down lead judgment, Dingemans LJ contrasted the approaches of the judges below, when evaluating whether noise surveys had been carried out:
‘It appears that Garnham J made a positive finding that there was a failure to carry out a noise survey rather than a finding that a noise survey had been carried out but was not available, whereas HHJ Vosper QC had made a finding that it was not possible to find as a fact that Alcoa were in breach of duty in failing to carry out a noise survey’.
Moving on to caution Appellate Courts against overturning findings of fact made by 1st instance Judges, His Lordship identified that the prospect of noise surveys potentially having been ‘lost’ by the defendant was sufficient to deter him from making an adverse inference.
Reliance on Engineering Evidence?
Equally, Dingemans LJ observed that the 1st instance Judge had been entitled to accept the available engineering evidence without drawing adverse inference, thus insinuating that Garnham J had acted in ultra vires, when dealing with mere findings of fact:
‘The approach taken by Garnham J. to the adverse inference risked elevating the decision in Keefe to a rule of law, rather than an example of the proper approach to finding facts in a particular case where the evidence showed that the defendant had failed in its duty to carry out noise surveys, and the claimant had been deprived of the opportunity to prove his case’.
Acceptance of the Claimant’s Historic and Innocently Exaggerated Memory?
Preserving identical treatment for both litigants, Dingemans LJ deliberated that, if it were to be established that the defendant had been prejudiced by the passage of time, in producing noise surveys, then the claimant’s ‘honest recollection’ of working times and working conditions would also have been ‘disadvantaged’ over the same time period.
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Accordingly, the defendant’s appeal was unanimously allowed and HHJ Vosper’s decision was reinstated.
Full text judgment of the Court of Appeal can be accessed here.
DISCUSSION
After the High Court judgment was handed down, counsel for the claimant heralded Garnham J’s ruling, as it made clear that:
‘... when a defendant is under a duty to measure levels of a toxin (such as noise, or dust), they must provide those measurements, or explain why they cannot do so, otherwise a claimant may establish breach even in the absence of supportive expert evidence’.
The dangerous precedent, established at the first appeal, was that it reversed the burden of proof from the claimant (proving excessive noise exposure) to the defendant (proving under-excessive noise exposure).
The detrimental effect of this was that the defendant had effectively been held in ‘automatic’ breach of duty, irrespective of the fact that noise levels were likely to have been well below the threshold of action. The only means for the defendant to contest breach of duty was to provide evidence of noise surveys.
Thankfully, this assumption has been reversed by the Court of Appeal.
Notwithstanding this, at paragraph 54 of his judgment, Dingemans LJ advised that:
‘In future cases where it is relevant to determine whether a noise survey has been undertaken in the past it would be helpful if both parties addressed that in pre-trial questions about the existence of documents or in the evidence at trial. This would help to avoid a situation where the trial judge is left to deal with the factual finding about whether a noise survey was carried out on the basis only of submissions about lists of documents’.
HMCTS list of documents Form N265 for completing standard disclosure:
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N.B. Dingemans LJ brought attention to an error, made at the High Court, by which Garnham J unintentionally misdescribed the 3rd edition of the guidance document: Noise and the Worker (1971), as the 2nd edition (1968). The upshot of this was that was that the common law duty to carry out noise surveys could only have arisen from 1973 to 1974 (2-years after the 3rd edition was published).256
256 Accords with Baker v Quantum Clothing Group Ltd [2009] EWCA Civ 499 and dicta of HHJ Inglish, at 1st instance (Parkes v Meridian [2007] EWCH B1 (QB)).
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Disclaimer
This newsletter does not present a complete or comprehensive statement of the law, nor does it constitute legal advice. It is intended only to provide an update on issues that may be of interest to those handling occupational disease claims. Specialist legal advice should always be sought in any particular case.
© BC Legal 2016.
BC Legal is a trading name of BC Legal Limited which is registered in England and Wales under company number 08963320. We are Authorised and Regulated by the Solicitors Regulations Authority (SRA No 617698).The registered office is 1 Nelson Mews, Southend-on- Sea, SS1 1AL. The directors are Boris Cetnik and Charlotte Owen. More details on the firm can be found at www.bc-legal.co.uk.
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