Otoacoustic Emissions: an 323), 923 Robie Street, Halifax, Nova Scotia, B3H 3C3, Canada, Tel: 902-420-5846, Fax: 902-496-8287; Email

Central Annals of Otolaryngology and Rhinology

Short Communication *Corresponding author

Andrea L.O. Hebb, Department of Psychology, Saint Mary’s University, McNally Building South Wing (MS Otoacoustic Emissions: An 323), 923 Robie Street, Halifax, Nova Scotia, B3H 3C3, Canada, Tel: 902-420-5846, Fax: 902-496-8287; Email:

Invaluable Screen of Neonatal Submitted: 13 November 2018 Accepted: 04 December 2018 Hearing Published: 05 December 2018 ISSN: 2379-948X 1 1,2 Scott A. Davenport , and Andrea L.O. Hebb * Copyright 1Department of Psychology, Saint Mary’s University, Canada © 2018 Hebb et al. 2Divisions of Neurosurgery, Otolaryngology─Head & Neck Surgery and Department of Radiation Oncology, Dalhousie University, Canada OPEN ACCESS

Keywords Abstract • Otoacoustic emissions Otoacoustic emissions (OAEs) including evoked otoacoustic emissions test (EOAE), • Hearing automated auditory brainstem response (a-ABR), transitory evoked otoacoustic • Hearing loss emissions (TEOAEs) and brainstem auditory evoked potential (BAEP) are invaluable in assessing hearing in the newborn and non-verbal children and young adults. The following article briefly outlines the implementation of OAEs in clinical settings and highlights future research potential.

INTRODUCTION delay, cognitive motor or visual disabilities brainstem auditory evoked potential (BAEP) may be recommended [6]. Comparing Otoacoustic emissions (OAEs) are low-level signals emitted the BAEP, a-ABR, and auditory transitory evoked otoacoustic inside the cochlea and recorded in the auditory canal. OAEs were emissions (a-TEOAE); measuring the variables of sensitivity, theorized over 60 years ago by the biophysicist Thomas Gold [1]; although his proposal of an active cochlear process was not ratio demonstrated that overall the BAEP was the better test. specificity, positive and negative predictive value and odds recorded and - tentatively - explained by Kemp who used a low- widely accepted until the 1970s. The first human OAEs were to be predictions, and a much lower false positive rate than the EOAE level click as the stimulus and recorded the cochlear echoes [2, 3]. andThe a-ABRBAEP had[6]. higher sensitivity and specificity, accuracy in its Since Kemp’s observation and subsequent experiment(s) OAEs have been studied extensively and implemented as a routine OAE use neonatal screening test for hearing loss. In addition, neonatal hyperbilirubinemia, familial auditory neuropathy, end-stage loss occurring in 1-3 infants per 1000 in Canada [9]. Otoacoustic emissionsHearing (OAEs) loss is are a common often used deficit, in combination with severe with to profound detailed the conditions which may precipitate hearing loss in children medical histories to reveal the etiology of hearing loss in infants andrenal in disease, which OAEsand neurofibromatosis have been utilized type[3-7]. II The(NF2) purpose are some of the of ensuing discussion is to demonstrate the effectiveness of OAEs typically normal in familial auditory neuropathy with absence (and the various tests inspired by the mechanism) as a versatile of[7, auditory 10]. For brainstem example, responses otoacoustic [7]. emission The OAE recordings is a normal are component of screening and experimentation. physiologic response generated by the outer hair cells of the Comparison of tests cochlea. A hearing sensitivity of 30 dB HL is indicated by a pass on an OAE test [11]. Hospital based universal neonatal hearing screening programs are at present widely used; the most effective ones Hyperbilirubinemia are evoked otoacoustic emissions test (EOAE), followed by an Hyperbilirubinemia has devastating effects on the auditory automated auditory brainstem response (a-ABR) for all infants system. Even short term increases in bilirubin levels can induce temporary or permanent changes in evoked potentials [4]. for detecting hearing loss in high-risk neonates has not been fully Baradaranfar et al. conducted a study on newborn babies with elucidated.failing the EOAE Examinations [3, 6, 8]. Thehave accuracy often been and hampered efficacy of by these excessive tests environmental electrical “noise”, electro-myogenic interference ABR, 9 with abnormal ABRs, 5 had no ABR waves at all and 4 (from behavioural distress), and cochlear immaturity [6, hadjaundice increased [4]. I-III Thirty-five and III-V infants intervals were and tested, latency 26 in had all normalwaves. 8]. Subsequently, visual reinforcement audiometry (VRA) is Twenty-six infants had normal hearing, 4 mild to moderate typically recommended, however, in the case of developmental

Cite this article: Davenport SA, Hebb ALO (2018) Otoacoustic Emissions: An Invaluable Screen of Neonatal Hearing. Ann Otolaryngol Rhinol 5(5): 1222. Hebb et al. (2018) Email: [email protected] Central hearing loss, and 5 suffered from severe to profound hearing loss. screening and experimentalresearch on mechanisms underlying OAE could be recorded in 1 infant with mild to moderate hearing hearing loss. loss and 4 with severe to profound hearing loss. Overall, 26 had normal tests and in 5 infants, abnormal results were localized to REFERENCES the retro-cochlear region indicative of auditory neuropathy [4]. 1. Gold T, Pumphrey RJ. Hearing. I. The cochlea as a frequency analyzer. Proc R Soc Lond B Biol Sci. 1948; 135: 462–491. Kidney Disease 2. Kemp DT. Stimulated acoustic emissions from within the human Abnormalities in auditory systems are frequent in children auditory system. JASA. 1978; 64:1386–91. with end-stage renal disease (ESRD); there is not yet any 3. Pigasse G. Deriving cochlear delays in humans using otoacoustic consensus for the effect of renal failure and hemodialysis on emissions and auditory evoked potentials. Technical University of auditory complications [5]. In a study conducted by Naderpour Denmark. 2008; 1-177. et al.children were tested in three groups: 25 ESRD patients 4. Braadaranfar, M.H., Atighechi, S., Dadgarnia, M.H., Jafari, R., Karimi, G., undergoing hemodialysis, 25 non-dialytic patients with chronic Mollasadeghi, A., Eslami, Z., & Baradarnfar A. (2009). Hearing status in renal failure, and 25 age and sex-matched control subjects [5]. neonatal hyperbilirubinemia by auditory brain stem evoked response ABR testing was abnormal in 11 dialysis patients with normal and transient evoked otoacoustic emission. Acta Medica Iranica. 2009; results in all 25 non-dialytic patients with chronic renal failure 49: 109-112. cases and controls. OAE testing was abnormal in all dialytic 5. patients with abnormal ABR testing. Sensorineural hearing Movaghar, M.H. Auditory brain stem response and otoacoustic loss was rare among non-dialytic patients with chronic renal emissionNaderpour, results M., in Mortazavi, children with F., end-stage Jabbari-Moghaddam, renal disease. Y., International & Sharifi- failure but very common in ESRD children undergoing long-term Journal of Pediatric Otorhinolaryngology. 2011; 75, 704-707. dialysis [5]. 6. Suppiej A, Rizzardi E, Zanardo V, Franzoi M, Ermani M, Orzan E. Reliability of hearing screening in high-risk neonates: Comparative Neurofibromatosis type II (NF2) study of otoacoustic emission, automated and conventional auditory Children with NF2 have an increased risk for hearing loss. brainstem response. Clinical Neurophysiology. 2007; 118, 869-876. Otoacoustic emissions are forms of energy (sound) generated 7. Wang, Q., Gu, R., Han, D., & Yang, W. Familial auditory neuropathy. The by the outer hair cells of the cochlea and can be used to assess Laryngoscope. 2013; 113, 1623-1629. cochlear hearing loss. Evoked otoacoustic emissions (EOAEs) 8. Kanji A, Khoza-Shangase K, Moroe N. Newborn hearing screening pro- have been used to assess outer hair cell and cochlear hearing tocols and their outcomes: A systematic review. Int J Pediatr Otorhi- nolaryngol. 2018; 115:104-109. 15]. Although typically used in infants, EOAEs have been used loss function in non-verbal neurofibromatosis NF2 patients [12- 9. Eskander A, Papsin BC. Screening infants for hearing impairment in to assess cochlear function in adult non-verbal NF2 patients Canada. CMAJ. 2014; 186: 1048-1049. [unpublished observation, 13]. 10. Chen MM, Oghalai JS. Diagnosis and Management of Congenital Canadian Research Sensorineural Hearing Loss. Curr Treat Options Pediatr. 2016; 2: 256- 265. Robert V. Harrison (2018) has repeatedly demonstrated OAE measurement as an important clinical and research tool. In 11. Jerry J, Oghalai JS. Towards an etiologic diagnosis: assessing the patient with hearing loss. Adv Otorhinolaryngol. 2011; 70: 28-36. terms of newborn hearing screening, OAEs testing is used even more than the standard behavioural audiogram [16]. OAEs can 12. Telischi FF, Roth J, Stagner BB, Lonsbury-Martin BL, Balkany TJ. be used to test outer hair cell integrity [17]. While ipsilateral and Patterns of evoked otoacoustic emissions associated with acoustic contralateral OAE suppression can be used to test some aspects neuromas. Laryngoscope.1995; 105: 675-682. of auditory brainstem functioning; the full potential of OAE in 13. Maritime Lateral Skullbase Clinic (2018). Halifax, NS. Canada. clinical testing has not yet been reached [16]. 14. Gouveris HT, Victor A, Mann WJ. Cochlear origin of early hearing loss CONCLUSION in vestibular schwannoma. Laryngoscope. 2007; 117: 680–683. 15. Prasher DK, Tun T, Brookes GB, Luxon LM. Mechanisms of hearing OAEs and other objective tests (BAEP, aABR)are invaluable loss in acoustic neuroma: an otoacoustic emission study. Acta non-invasive screening tests that are applicable to many conditions Otolaryngol. 1995; 115: 375–381. including but not limited to neonatal hyperbilirubinemia, 16. Harrison, R.V. The biggest paradox in audiology. Canadian Audiologist. familial auditory neuropathy, end-stage renal disease and NF2. 2018; 5. The irrefutable exemplary implementation of OAEs into the 17. Kemp DT. Otoacoustic emissions, their origin in cochlear function, wider variety of applications. OAEs are a valuable resource for and use. Br Med Bull. 2002; 63:223-41. field of medicine and research only bolsters the potential for a

Cite this article Davenport SA, Hebb ALO (2018) Otoacoustic Emissions: An Invaluable Screen of Neonatal Hearing. Ann Otolaryngol Rhinol 5(5): 1222.

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