Standard and Simplified Methods for Measuring the Sound Insulation in Dwellings in the Field

by Chiak Hwee Lim

A Thesis submitted as part of the fulfilments for the Degree of Master of Science (Acoustics) School of Architecture New South Wales University January 1977 UNIVERSITY OF N.S.W.

16781 -3.AUG.77 LIBRARY - - Abstract

Many countries nowadays have building codes which aim to regulate noise

control in dwellings. In many cases, airborne and impact sound insulation

performance requirements are based on laboratory tests. Also, in most

standards, tedious, time consuming and uneconomical test methods are

specified. In this thesis, field sound insulation measurements based on

standard and simplified methods are reported. For the examples measured

it was found that a simplified third-major-diagonal distance measurement method is valid for checking the airborne sound transmission loss properties of partitions and party walls in and between dwellings.

However, noise control in dwellings should go further than specifying

required STC values of party walls and partitions. It is suggested that

sound isolation would be a more appropriate criterion while STC values

could be used as the design guide. Finally, some recommendations to

improve the effectiveness and usefulness of a building code are made. ACKNOWLEDGEMENT

The author wishes to thank his supervisor, Associate Professor

A. Lawrence for her guidance and assistance during the preparation of this thesis.

The author is also grateful for the assistance of Mr. R. Rosenberger in carrying out field tests and laboratory analysis and for the constructive criticism Mr. E.T. Weston of Experimental Building

Station has given on the test results.

The author would also like to thank the New South Wales Housing

Commission, Messrs. C.N. Liew and F. Wong for the permission to carry out tests in their buildings, and M. Lim for her encouragement and assistance. List of symbols

2 A measured room absorption in m -sabins 2 Ao reference room absorption in m -sabins ASTM American Society for Testing and Materials

CNEL Community Noise Equivalent Level dB decibel dB (A) decibel in A-weighting dB (C) decibel in C-weighting

Dn normalised level difference (to AQ)

Dn(t) normalised level difference (to TQ) FHA U.S. Federal Housing Administration

Hz Hertz, cycle per second

HPWG British house party wall grading curve xa airborne sound insulation index xi impact sound insulation index

INR impact noise rating

IIC impact insulation class

XP privacy index Ir sound intensity in receiving room

Xs sound intensity in source room ISO International Organisation for Standardisation

L1 sound pressure level in source room, dB L2 sound pressure level in receiving room, dB A-weighted background noise level > >

A-level difference between two rooms ala

^As A-weighted sound pressure level in source room

LAr A-weighted sound pressure level in receiving room

LCs C-weighted sound pressure level in source room

(i) ^n normalised impact sound pressure level in receiving

Ma airborne insulation margin

M± impact protection margin

NIC noise isolation class

NC noise criteria

PNC preferred noise criteria

NR noise reduction

Pr pressure received by microphone in receiving room

Ps pressure received by microphone in source room

R, STL laboratory sound transmission loss, dB

R', FSTL field sound transmission loss, dB

2 S area of test wall m s standard deviation

SIL speech interference level

PSIL preferred speech interference level

SLM sound level meter

SPL sound pressure level

SPR speech privacy rating

STC sound transmission class

FSTC field sound transmission class

SSTC simplified sound transmission class

RT reverberation time, seconds

T measured reverberation time, seconds

To reference reverberation time, seconds

X average of all samples taken - mean deviation

__***** CONTENTS

page

Abstract Acknowledgement List of symbols (i)

1.00 INTRODUCTION 1 1.10 Background of Existing Sound Insulation Requirements 1 1.11 Airborne Sound Insulation 2 1.12 Impact Sound Insulation 5 1.20 Sound Insulation and Sound Isolation 5 1.30 Summary 6

2.00 NOISE IN DWELLINGS 7 2.10 Noise as A Problem at Home 7 2.20 Effects of Noise on Man 7 2.21 Disturbance of Sleep 8 2.22 Annoyance 10 2.23 Speech Interference 11 2.30 Noise Sources 13 2.31 Interior Noise 13 2.32 Exterior Noise 14 2.40 Recommended Noise Levels in Dwellings • 15 2.50 Background Noise 18

3.00 STANDARD METHODS OF FIELD MEASUREMENT OF SOUND INSULATION: TECHNIQUES AND ASSOCIATED PROBLEMS 20 3.10 Introduction 20 3.20 Concept of Sound Transmission Loss 21 3.30 Field Measurements of Airborne Sound Transmission Loss in Buildings 23 3.31 Method of Measurements 23 3.32 Field vs Laboratory Measurements 26 3.40 Factors That Cause The Inaccuracy of Results 27 3.41 Room Diffusion 28 3.42 Effects of Flanking 30 3.43 Sound Transmission Through Windows, Doors and Other Installations 31 3.44 Workmanship 32 3.45 Temperature Effect 33 3.46 Loudspeaker Arrangements 34 3.47 Number of Microphone Positions 36 3.50 Field Measurements of Impact Sound Insulation in Building 36 3.51 Introduction 36 3.52 Method of Measurements 38 3.53 Criticisms on the Use of ISO Tapping Machine 39 3.54 Comments 41 3.60 Conclusion 42 page

4.00 SOME PROPOSED SIMPLIFIED METHODS OF MEASURING AIRBORNE SOUND INSULATION IN BUILDINGS 43 4.10 Introduction 43 4.20 The Simplified Methods 44 4.21 Siekman's et al. Proposed Method of Simplified Field Sound Transmission Test 44 4.21.1 Source 44 4.21.2 Instrumentation 44 4.21.3 Measuring Position at Source Room 45 4.21.4 Measuring Position at Receiving Room 46 4.21.5 Calculation 46 4.22 Quindry and Flynn's Proposed Method of Simplified Field Measurement of Noise Reduction between Spaces 47 4.23 Rettinger's Proposed Method of Simplified Field- Measured Sound Insulation 48 4.24 Tricaud's Proposed Method of Impulse Techniques for the Simplification of Insulation Measurements between Dwellings 49 4.25 Van den Eijk's "My Neighbour's Radio" Theory 51 4.26 Schultz's A-level Difference in Acoustical Isolation Rating 52 4.27 Stephen's Proposed Method of Measurements of Sound Insulation with Sound Level Meter 53 4.30 Correlation between Simplified Methods and Sound Insulation Rating based on ISO or ASTM Recommendations 55 4.40 Why dB(A)? 57 4.50 The Modified Laboratory 58

5.00 AIRBORNE AND IMPACT SOUND INSULATION REQUIREMENTS IN DWELLINGS 60 5.10 Introduction 60 5.20 Airborne Sound Insulation Rating Systems 60 5.21 ASTM STC Rating System 61 5.22 ISO Ia Rating System 62 5.30 Impact Sound Insulation Rating Systems 62 5.31 ASTM/FHA Impact Rating Systems 63 5.32 ISO 1-^ Rating System 65 5.40 FHA Recommendations 66 5.50 Some Notes on Single-figure STC Rating 68 5.60 The True Value of STC 71 5.70 Airborne Sound Insulation Requirements for Dwellings in New South Wales 71 5.80 Conclusion 73

6.00 FIELD SURVEY OF THE SOUND INSULATION WITHIN AND BETWEEN DWELLINGS 75 6.10 Introduction 75 6.20 Preliminary Survey 76 page

6.30 Measurements 77 6.40 Presentation of Results 80 6.50 Discussion of Results 80 6.51 Walls 80 6.52 Floor-ceiling Assemblies 82 6.53 Comments on Accuracy of Measurements 82 6.54 Possible Means of Increasing the Insulation Properties of These Wall Types 84 6.60 Comparison of Results - Classical and Simplified Methods of Sound Insulation Measurements 85 6.70 Conclusion 86

7.00 CONCLUDING COMMENTS 89 7.10 Introduction 89 7.20 Sound Isolation and Insulation 89 7.30 Recommendations 90 7.40 Conclusion 93

APPENDICES Appendix 1 Al.l Appendix 2 A2.1 Appendix 3 A3.1 Appendix 4 A4.1 Appendix 5 A5.1 Appendix 6 A6.1

REFERENCES R(l) 1.00 INTRODUCTION

Many countries already have acoustical requirements incorporated with

their building regulations, mainly to ensure adequate sound isolation

or privacy between dwellings. But in many instances, these require­

ments are not consistently enforced. Even with strict enforcement,

the chance of achieving adequate privacy is still dubious. This

failure, as Schultz (Refs. 155-157) pointed out, "is sufficient

evidence that noise control presents formidable practical difficulties"

Most regulations, including the one in New South Wales (Ref. 34),

generally specify a Sound Transmission Class (STC) of 45 or 50

depending on circumstances, (e.g. whether two similar rooms are

adjacent to one another or if a bedroom is adjacent to a kitchen)

but they do not take into account that sound travels from one room

to another in a building in a more complicated way than through the

dividing partition alone; it follows many other paths, some of which

may be just as important as the primary. Unfortunately buildings are

not normally designed with adequate attenuation in all the possible

paths by which sound from one room may reach the other rooms of the

building. It shows that building codes should go further than just

specifying the Sound Transmission Class of the dividing partition,

they should consider all other possible sound paths as well.

1.10 Background of Existing Sound Insulation Requirements

Most of the existing sound insulation requirements are based on

experience with traditional constructions and this is reflected in

the shape of the standard grading curve. Many surveys (Ref. 132) in

Great Britain, Sweden and the Netherlands indicate that two-thirds

1 of the tenants separated by a 230mm brickwall are reasonably

satisfied with the sound insulation that it provides. Therefore this

construction was accepted as a starting point in the research for an

exemplary curve and eventually even for a requirement curve.

Thus, many countries such as America, Sweden, Germany, Great Britain

and ISO etc. have their own rating curves but they are all identical

in shape except the frequency ranges may differ, e.g. the ISO rating

curve ranges from 100-3150 Hz while the ASTM rating curve ranges from

125-4000 Hz. (See Fig. 25).

1.11 Airborne Sound Insulation

The first sound insulation requirements for dwellings in Europe were

in fact presented just before and after World War II (Ref. 57). For

airborne sound insulation, the insulation requirements covered the

frequency range from 100 to about 3000 Hz and were based on one, two

or three arithmetical mean figures within this range. This faced

much criticism and it was thought wrong that a low insulation in one

part of the frequency range could be compensated for by a high

insulation in another frequency range and thus receive the same

figure of quality as for a construction with reasonably good

insulation at all frequencies.

About twenty-two years ago, Germany introduced a grading curve to

replace the simple figure rating. Fig. 1 shows such a grading curve

with a frequency range from 100 to 3150 Hz. If all values are above

this grading-curve values, the airborne sound insulation is acceptable.

If they are below them, then the insulation is not up to the standard,

2 except that an average negative deviation over the whole frequency range is less than 2dB is allowed.

Based on this rule, a new single figure (Refs. 36 & 40) for airborne sound insulation is established and the Germans named this figure as

Luftschallschutzmass, which is translated as Airborne Insulation

Index for a more common international use. Fig. 2 shows how this curve differs from those of other countries.

The British Grading Curves which relate insulation to disturbance were obtained from Social Surveys giving tenants' reactions to neighbour's noise and from objective measurements of the insulation with which they lived. The investigation began with the two types of walls, 230mm solid and 280mm cavity brick walls in traditional

British houses. The walls have average (of frequencies ranging from

100-3200 Hz) single figure insulation values of 50 dB and 55 dB respectively but the comparison of the tenants' reaction through social surveys showed that there was no distinguishable difference in the disturbance to the tenants between the two kinds of insulation.

Fig. 3 shows the results of the objective measurements of both walls, indicating that the insulation for the cavity wall is better of only at high frequencies. Since the survey showed that few people would pay for better insulation if this could be obtained, the 230mm solid wall curve was taken as the standard (Ref. 141).

Based on the same principle, Grade I and Grade II grading curves were developed. Three groups of multi-storey flats were chosen for the survey. The high performance group had the best floor insulation reasonably obtainable:- floating concrete floors, average airborne sound insulation 50 dB, the medium group, with solid floors with

3 field tests

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than the first and a low insulation group was 5 dB further down still.

The latter group was afterwards found to be sufficiently different

in a number of ways as to make them uncharacteristic (Ref. 141).

Thus these results were not subsequently used in establishing the

Grades. The average measured values of insulation for the high and

medium groups were replaced by straight lines to give the Grade I,

II and Impact Grading Curves as shown in Figs. 4 & 5 respectively.

Grade I insulation corresponds to the neighbour's noise being only as

disturbing as several other things and Grade II insulation

corresponds to the neighbour's noise being to many of the tenants

the worst thing about living in the flats. However, even with Grade

II at least half of the tenants are not seriously disturbed, but

serious complaints would arise if insulation is lowered 8 dB below

this Grade.

The Americans developed their grading curve differently. The Sound

Transmission Class used was originally based on the amount of attenuation required to reduce each octave-band level of a "standard

household noise" spectrum, (the spectrum of a composite of live

speech, radio, television music and speech, vacuum cleaner, and air-

conditioner noise), to match the levels of the 0.5 Sone equal-loudness

contour, the 0.5 Noy equal-noisiness contour and the NC-25 contour

respectively (Ref. 133). The resulting three attenuation curves were quite similar and an average of the three was adopted as an

idealised transmission loss curve against which any subsequent measured transmission loss curve could be compared for the assign­ ment of a single number rating of the airborne sound insulation of a partition or floor under test. The curve was found to be very

4 similar to the existing German curve, although the frequency range

used differed slightly. Fig. 6 shows the derivation of the curve

and the single number rating obtained through the curve is called

Sound Transmission Class.

1.12 Impact Sound Insulation

The German impact sound insulation grading curve has its origin

slightly different from that of airborne sound insulation. In fact

a standardised tapping machine is used for the test of floors and

measurements are made either in octaves or one-third octave bands

with the frequency range same as airborne sound insulation. The

measured levels are corrected to 0.5 sec. room reverberation time or 2 10 metric sabins (10m ) room absorption (Refs. 36 & 37). A high

level of impact sound indicates bad insulation while a low level is

an indication of good insulation. Fig. 7 shows such the grading

curve and Fig. 8 shows how this curve differs from those of other

countries.

A single figure for impact sound insulation similar to the airborne

insulation index, also was first introduced by the Germans (Ref. 57).

This single figure is the number of decibels that the grading curve

has to be lowered or raised according to the rule mentioned before.

It is known as Trittschallschutzmass to the Germans, which means

Impact Insulation Index.

1.20 Sound Insulation and Sound Isolation

The sound insulation properties of a partition and the sound isolation

between rooms are entirely two separate things. The insulation

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Sound Transmission Class (STC), Sound Reduction Index (R) or Airborne

Sound Insulation Index (Ia) and the isolation between rooms is termed

Noise Reduction (NR) or Normalised Level Difference (Dn). Isolation

between rooms can easily be judged subjectively as the total noise

reduction between the two rooms in question, not that through the

partition alone. It may or may not involve flanking transmission.

However, the distinction between isolation and insulation is quite

frequently overlooked and the issue of partition insulation is

usually the main topic in any acoustical discussion of sound insulation.

1.30 Summary

Many investigators have suggested that sound isolation between rooms

and not the laboratory tested insulation properties of the partitions

should be used for specifying noise control in buildings; in addition,

the standard or classical sound transmission loss test is thought to

be too time consuming and uneconomical and it should be replaced by

a simpler method.

This will be discussed in more detail in the following chapters.

-kkk __ 2.00 NOISE IN DWELLINGS

2.10 Noise As A Problem At Home

Noise as a problem at home is not an entirely new phenomenon, but is

a problem that has grown steadily worse with time. The mechanization

of domestic appliances has caused the noise nuisance to escalate

dramatically in both its severity and extent. But unfortunately,

people suffering from stress and emotional disturbances frequently

do not realise that noise may be an important contributing factor.

Furthermore, noise degrades the quality of our lives and detracts

from the enjoyment of living. Though noise at home may not be

intense enough to induce hearing impairment, its adverse effects are

certainly high enough to interfere with sleep and normal conversation.

It is interesting to note that the tolerance of people to withstand

noise of different types will vary from one person to another. One

person may prefer louder music than the others, and this often leads

to conflict in the home.

2.20 Effects of Noise on Man

Noise is widely known as unwanted sound. It is classified as

unwanted by virtue of its level, nature, character and the times at

which it occurs. But, no single noise is likely to evoke exactly

similar responses from all of the individuals in a population exposed

to it. The degree of rejection depends entirely on the receivers.

Sometimes very loud sound may be regarded with indifference while on

the other hand an uncommon sound, though very faint, may cause

significant disturbance.

7 groups: Direct and Indirect effects. The direct effects constitute

aspects of the perception of the noise itself and result in

immediate subjective consequences, for instance, the masking of

speech results in the reduction of speech intelligibility. Indirect

effects include annoyance, disturbance of sleep or rest, disturbance

of work performance or activities, these thus tend to cause adverse

effects on health.

There is a wide range of effects that noise can have on individuals.

Those effects which are more pertinent to the home environment will

be extracted and discussed in greater detail.

1.21 Disturbance of Sleep

The effect of noise on health is an indirect one, for example it may

cause loss of sleep or frustration in carrying out work or household

chores. If this is allowed to persist, the effect on health is

undisputably serious. It is true that man has the power of adaptation

to his environment, and can become accustomed to noise as he can to

other environmental factors, so that satisfactory sleep can be

obtained in conditions which would at first render sleep impossible.

Sometimes, those accustomed to certain noises even find their absence

an impediment to falling asleep.

Though man possesses the power of adaptation to noise, there is a

limit to the intensity of noise, after which its existence becomes

less endurable, and it may then make falling asleep difficult or

awaken a sleeper, who will have great difficulty in falling asleep

8 again. If there is resentment against the cause of the noise, the state of mind suitable for sleep is even harder to achieve.

During sleep, muscular relaxation is almost complete, the heart rate decreases and blood pressures is lowered, the rate and depth of respiration is reduced and the nervous system is less active. It is widely agreed that sleep is an essential period of physical and mental restoration and, if reduced in duration or depth over an extended period, physical and mental health suffers.

The depth, continuity and duration of sleep can all be affected by noise. Noise intrusion during sleep can affect its recuperative value. The most essential phase of sleep is known as the dream stage when a person is in deep sleep and is particularly insensitive to sound. This stage is characterised by rapid eye movement (REM), occuring predictably five to six times nightly and it accounts for

20-25% of adult sleep time (Ref. 5 p. 80). When sleep is deep, awakening by noise is less likely, but on the other hand, there are times when sleep is light and awakening is easy. But apart from the intensity of sound, awakening is dependent on the type and significance of the sound. Sound which is familiar, for example, air conditioning noise, is not only less liable to awaken or prevent individuals falling asleep but also allows adequate sleep. But to the guest unaccustomed to the noise, falling asleep could be a lengthy process, or even impossible. When the sound is significant, for instance, a baby's cry, awakening is an instant action.

In view of the varied and complicated relations individuals have with noise, it is practically impossible to set down rules for preventing disturbance of sleep or rest. The most common method

9 used is to suggest a maximum permissible level for its design

criterion of sleeping accommodation, taking into consideration other

possible factors like intermittent traffic noise (Ref. 51).

2.22 Annoyance

Annoyance may be described as the personal displeasure or resentment

caused by a particular noise in a specific environment. Therefore,

it is difficult to measure noise annoyance and the results are

possibly subject to biasing effects (Ref. 9 p. 68). The psychological

and physiological factors are so complex and vary so much from

individual to individual that any theoretical attempt to anticipate

any one person's reactions to noise seems impossible. But it is

possible to obtain some indication of annoyance caused by noise by

collecting numerous peoples' reactions to noise through questionnaires.

The nature of the noise annoyance depends very much on the circum­

stances, viz, noise level, frequency or intermittency, time at which

it occurs and other characteristics. The factors which appear to

determine the degree of annoyance could be summarised as follows

worried, sick and psychologically disturbed people seem

to be most affected

people's emotional character, stamina and general outlook

control the considerable differences of susceptibility to

noise

in certain circumstances, some people may find noise

exciting and emotionally satisfying, others hardly at all

in most circumstances, young people are less likely to be

irritated than old people

10 r* the level of noise to which people have been accustomed

will influence their attitude towards it

- people are more likely to complain of a new noise than

the one they have heard before

if people think of noise as being unavoidable, they may

be less irritated than if they consider it unnecessary

bias, like personal dislike of a neighbour will result in

noise generated by the neighbour being considered more

annoying

Many investigations of noise disturbance have been carried out and

results show that road traffic noise remains the greatest source of

disturbance (Ref. 6 pp. 128-129, Ref. 112). Of course, people

staying close to airports indicate that disturbance from aircrafts

is their major noise problem. But in terms of population, people

exposed to road traffic noise constitute the major proportion of the

victims.

2.23 Speech Interference

The ability to hear a given sound without undue strain depends to a

considerable extent on the level of background noise, which is either

the noise generated around the listener, such as room noise, or

noise entering the room from outside such as neighbour’s noise or

traffic noise. If the level of general room noise is high, external

noise will be masked so that it becomes less noticeable, or on the

other hand, when the external noise level is higher, then some

impairment on speech perception becomes inevitable.

11 The masking of one sound by another is a complicated phenomenon. It depends not only on the relative intensities and frequency structures of the two sounds, but also on the mental attitude of the listener.

If the background noise is continuous, interference will be greater than if it were intermittent. The intelligibility of speech will also depend on the type of spoken material used, and if it is suitable under the particular room acoustical conditions. Suitable use of speech procedures and vocabularies can help in attaining satisfactory communication where normal conversational habits would be inadequate.'

There are a number of ways in which the intelligibility of a given speech can be assessed. Beranek evolved a system called Speech

Interference Level (SIL) (Ref. 4) which is the arithmetic mean of the readings of background noise in decibels in three octave frequency bands, namely, 600-1200, 1200-2400 and 2400-4800 Hz. Webster (Ref.184) has also done similar research, and concluded with another criterion, which is called Preferred Speech Interference Level (PSIL), which the arithmetic mean of the overall SPL value of the octaves centred at 500, 1000 and 2000 Hz. The SIL (or PSIL)* can be effectively used to ascertain the condition under which speech communication in relatively easy, difficult or impossible, by comparing with Table 1 or 2. Table 1 and Table 2 show his PSIL values based on the octaves

* SIL based on the average of the overall SPL value of the octaves centred at 600-1200, 1200-2400 and 2400-4800 Hz, is no longer used due to outdating of the frequency range. Instead SIL based on the average of the overall SPL value of the octaves centred at 500, 1000 and 2000 Hz is used. Though the latter may sometimes be referred as Preferred Speech Interference Level (PSIL), an abbreviation such as SIL is used instead of PSIL.

12 centred at 500, 1000 and 2000 Hz with an articulation index of about

0.4. Thus in order to communicate in a normal voice when less than

one foot away, the background noise level should not exceed 74 PSIL

(Table 1) or 82 dB(A) (Table 2). But a recent survey found that the

maximum acceptable level for background noise for voice communication

was 64 dB(C) or 71 dB(A) (Ref. 5 p. 71). Figs. 9a, 9b and 10 show

similar conclusions.

2.30 Noise Sources

Sometimes at home we may experience difficulty in understanding

conversation due to high noise levels. These noises are known as

interior noises or external noises, depending on the nature of their

origins. Perhaps it is more appropriate to call external noises as

outdoor noises, and any noises generated within a building as

internal noises and all noises entering into a room irrespective of

their origin, either from outdoor or another room, as intrusive noises.

2.31 Interior Noise

The most common interior noise sources are the television, radio,

hi-fi systems, door slamming, occupant activities, plumbing noise,

household appliances, electro-mechanical equipments, and traffic on

floors and staircases. <

Technology is partly responsible for our environmental ills. Most

of the household appliances such as fans, motors, compressors,

refrigerators, dishwashers, garbage disposal units, washing machines,

dryers, vacuum cleaners, air-conditioners or heating system, food

blenders, electric shavers and hair dryers, etc. are unduly noisy.

13 TABLE 1 Preferred speech interference levels of noise that just permit conversation with marginal reliability at the distances voice levels indicated

Distance from PSIL listener dB*

m ft Normal Raised Very loud Shouting voice voice voice

0.15 0.5 74 80 86 92 0.3 1 68 74 80 86 0.6 2 62 68 74 80 0.9 3 58 64 70 76 1.2 4 56 62 68 74 1.5 5 54 60 66 72 1.8 6 52 58 64 70 3.6 12 46 52 58 64

* Average SPL in dB of noise in the octave bands centred at 500, 1000 and 2000 Hz. (From William Burns, "Noise And Man", page 186.)

TABLE 2 Speech Interference Levels

Distance from Face-to-face conversational levels speaker to Normal Raised Very loud Shouting listener in ft.

dBC dBA dBC dBA dBC dBA dBC dBA 0.5 75 82 81 88 87 94 93 100 1.0 68 75 75 82 82 89 87 94 2.0 63 70 68 75 75 82 81 88 3.0 59 66 66 73 72 79 77 78 4.0 57 64 63 70 68 75 75 82 6.0 54 61 59 66 66 73 72 79 8.0 52 59 57 64 63 70 69 76 10.0 48 55 54 61 61 68 67 74

(After Webster, J.C., 1969)

^ -u

4-1 WITH 'NORMAL vcnct’ O 4-1 C w Cd *rH

0.5 L- PSIL40

Fig.9a. Rating chart for determining speech communication capability from speech interference levels. (After Webster, J.C., 1969) ii n i i i i 111

Distances outdoor for conversation

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fro possible maximum effort

maximum effort

expected voice level

communication -practical

talker - listener distance-ft.

Fig. 10 . Qoalltcj of speech communication in relation to sound level of no^se and distance between talker and listener. (After Miller, J.T>., 1974) The pursuit of higher speed or greater output is unceasingly

increasing the noise levels. With the unsatisfactory design, inferior

materials and poor workmanship of current home construction, an

escape from the noise invasion becomes quite impossible.

There is indeed very little quantitative information available on

domestic noises generally. Very little consideration has been given

to the noise of household appliances while much attention and effort

have been spent on studying acceptable noise levels in industry and

the environment generally. Unlike television sets, radios and the

hi-fi systems, many household appliances have high noise levels over

which the users can exercise little or no direct control. The

noisiest area at home is normally the kitchen, with appliance noise

levels ranging from about 40 to 90 dB(A) (Ref. 96). Other room

appliances such as air-conditioners, etc. are slightly quieter but

bathroom or toilet appliances such as toilet cisterns, electric

razors, hair-dryers and electric tooth brushes are in fact as bad as

kitchen appliances. (See Table 3 and Fig. 11).

2.32 Exterior Noise

Many surveys indicate that road traffic is one of the most

significant external noise sources (Ref. 6 pp. 128-129, Ref. 112).

It includes motor cars, buses, trucks, motorcycles, trains and trams,

etc. The rapidly increasing number of aircraft is posing a threat

to our noise environment, particularly in areas under the flight paths

or around the airports. Other significant noises such as noises

from parks, a neighbour's air-conditioning system or lawn mower could

14 also be very annoying.

Radio noise has been examined in a more systematic way by Van den Eijk

of the Netherlands (Refs. 73, 76 & 77). Distribution of the radio

sound levels exceeding 5%, 10%, 20%, 40% and 60% is shown in Fig. 12.

He concludes that it is the frequency range of 400 to 800 Hz which

is of main importance for the abatement of nuisance from "my neigh­

bour's radio", and "if the airborne sound insulation between two

flats is great enough to reduce the annoyance caused by neighbour's

radio to an endurable level, the annoyance caused by other airborne

sound from the neighbouring flat will in the vast majority of cases

also be reduced to such an extent as to give no further cause of

compliant".

2.40 Recommended Noise Levels in Dwellings

Acceptable noise levels in a dwelling differ from one room to

another, mainly depending on the normal activity noise level within

them. Kitchens at certain times are noisier than other rooms, thus

normally they have a higher acceptable noise level. Bedrooms are

always the quietest compartments in the buildings and thus require

lower noise levels. The least noise tolerance is found in these

rooms, and in order to insure sleep, as The Wilson Committee Report

recommends, the noise level should not exceed 35 dB(A) (Ref. 5 p. 81)

measuring inside the dwelling unit.

Individuals react to noise differently. To certain people falling

asleep in a higher noise level is not a great problem, but only

unusual noises will disturb them, while to some individuals, under

the same condition, falling asleep can be a lengthy process or even

15 TABLE 3 House Appliance Noise Levels dBA

Appliance Minimum Average Maximum

Food mixers: slow 58.6 66.1 71.4 medium 62.4 71,9 83.1 fast 67.4 77.4 85.3 Food mixer slow 57.4 62.2 66.4 liquidiser medium 69.6 73.4 75.4 attachments fast 75.4 78.2 80.8 Purpose-built liquidisers 87.2 88.6 89.6 Whistling kettles 68.8 80.8 93.4 Washing machines: washing 54.0 66.3 73.6 drying 64.0 72.2 77.6 Hot-air tumble drier - 62.6 - Spin driers 69.2 71.9 74.4 Extractor fans 55.8 58.5 59.8 Dishwasher - 70.6 - Waste disposal unit - 66.6 - Gas cookers 37.4 44.4 53.8 Gas fires (full on) 28.0 34.3 42.0 Gas water heater (wall mounted) 58.8 62,8 66.0 Vacuum cleaners 67.0 76.5 82.5 Fan heaters: fan only 40.6 45.5 52.8 ' lkW 37.2 45.7 53.0 2kW 41.2 47.3 53.4 3kW 47.0 49.2 51.4 Hair driers: Hot 65.4 70.9 77.6 Cold 63.2 69.9 79.0 Electric tooth brush - 60,4 - Electric razors: Rotary 74.6 79.8 83.4 Shuttle 64.4 67.5 71.0 Flush toilets: High-level 79.8 82.3 85.2 Low-level 73.0 76.2 81.8

(After Jackson and Leventhall, 1975)

16 ___ _ rt^dfo noise...... vacvuno cleaner ------speech-peak levels ------air conditioner ------standard household noise

Mid-band p-e^uency c/s

Fig-. 11 Half - octave band spectra of typical household noises. (After MortWtoood, T. J)., t9 62)

Rtr cent of tirne level exceeded _

SO IOO 200 4-00 Boo (600 3/50 6300 Mid-band frequency c^a

FIG. 12 'Distribution of Sound levels of radio programs . (After Van den Eij^ > ) impossible. Thus there seems to be a wide range of tolerance in the noise levels that people can accept during sleeping, depending upon the nature of the noise, the nature of the residential area and the behaviour or temperament of the individuals towards the noise.

Living rooms are commonly used for conversation, watching television or entertainment, thus a different set of noise levels is acceptable.

For normal conversation, or the radio or television, operating at moderate levels, to be comfortably understood, the background noise should not exceed 35-45 dB(A), i.e. when the background noise should not exceed a SIL of 30 to 40 dB (Ref. 2 pp. 28-29). In fact in some residential areas away from the traffic network, the background noise level may be often as low as 20-25 dB(A).

The aim of a noise criterion is to describe the acceptability for an average person, and if one is dealing with real persons, the description may not necessarily be precise. However, some recommended noise criteria based on Beranek's findings (Refs. 4, 49 & 51) are shown in Table 4.

Table 4: Suggested noise criteria range for steady background noise as heard in various indoor functional activity areas

Type of Space PNC* curve Approx. L^ (and acoustical requirements) dB (A)

Bedrooms (for sleeping, resting and relaxing) 25 to 40 34 to 47

Living rooms and similar spaces in dwelling (for conversation, listening to radio or television) 30 to 40 38 to 47

Kitchens and laundries (for moderately fair listening conditions) 45 to 55 52 to 61

* PNC: Preferred Noise Criteria (Ref. 51)

17 2.50 Background Noise

Background noise plays a major role on human perception of any

intruding noise. The intruding noise will not be heard at all if in

each frequency band it is always below the ambient level of the room,

or alternatively below the thresholds of audibility of the listeners.

Even if it is heard, it would not necessarily be disturbing, but

still there is a good chance that it will be if it conveys some sort

of information to the listeners. For instance, the voice of a

nagging wife next door, although it is not intelligible, could be

most intolerable.

To ensure that the probability of intruding noise being heard is

reduced to a reasonably small number demands certain design criteria.

Some statistics on quiet ambient levlels in dwellings are required.

If the transmitted noise level is less than the background noise, it

will be effectively masked by the background noise and hence be

inaudible. On the other hand, intruding noise will become very

dominating when the background level (interior noise level) is too

low, i.e. it appears to be magnified in importance.

However, the use of background noise for masking is fraught with

numerous difficulties. Background noise is nearly always broad-band

noise and hence it will not effectively mask sounds which have

appreciable pure-tone components. If the background noise itself

is not to be disturbing, it should not only be broad-band, but also

smooth, continuous and essentially non-directional. These require­

ments exclude noise from road traffic (which is rarely continuous and

often increases greatly when trucks pass), as well as equipment such

18 as air-conditioner blowers due to the cyclic in nature of the source.

Of course, use of high background noise in some cases to compensate for acoustically inferior construction may result in occupants increasing the volume of their television sets, and thereby offsetting any beneficial masking effects.

— *** 3.00 STANDARD METHODS OF FIELD MEASUREMENT OF SOUND INSULATION;

TECHNIQUES AND ASSOCIATED PROBLEMS

3.10 Introduction

The techniques for field measurements of airborne and impact sound

insulation have already been standardised and have been adopted

nationally and internationally, for example, the BS 2750:1956 (Ref. 43),

ISO R140:1960 (Ref. 35) and ASTM E336-71 (Ref. 39). The task of

conducting field measurements of sound transmission loss of partitions

is quite unlike carrying out a similar test in a laboratory where the

facilities are idealised to conform with standards and test

specifications. The objective of the field test is to measure the

sound transmission properties of the partition in question, but not

necessarily to equate the results with results or data obtained from

a laboratory-measurement of a similar or identical partition.

Laboratory-measurement data should only be considered as a valuable

guide to the acoustical performance of the particular partition under

specified conditions.

Examples of the field measurements of both airborne and impact sound

insulation in selected dwellings will be discussed in Chapter six.

In this Section, the field test procedures and some associated

problems with field measurements will be discussed. Laboratory test

procedure will not be discussed and detailed information may be

obtained from the references given (Refs. 35, 39 & 43).

20 3.20 Concept of Sound Transmission Loss

The sound insulating property of a partition element is usually

expressed in terms of the airborne sound transmission loss which is

the ratio, expressed in decibels, of the sound power incident upon

the partition to the sound power transmitted through and radiated by

the partition.

In the laboratory test procedure, this ratio is determined by

mounting the partition between two reverberation rooms, one of which,

the source room, contains one or more sound sources. Under these

conditions, the transmission loss is related to the space-time-average

sound pressure levels in the two rooms, the area of the test partition,

and the total absorption in the receiving room. When these quantities

are measured in appropriate frequency bands, the transmission loss

as a function of frequency is found.

The problems of making reliable sound insulation measurements in the

field are much more difficult than those met in the laboratory. In

ordinary buildings, a great variety of test room shapes and sizes

will be encountered; the amount of energy exchange at the nominal

boundaries of the test specimen will vary widely; and there is often

a problem of flanking transmission, that is, of sound arriving in

the space of the receiving side of the test partition by paths other

than the one directly through the partition as shown in Fig. 13.

In principle, these same problems do exist in laboratory measurements,

but their influence is minimised by deliberately restricting the

measurements to conditions with random (diffuse) sound fields on both

sides of the partition by the adoption of appropriate dimensions for

21 the test chambers and for the test specimen, and by using special laboratory wall construction to reduce the effect of flanking transmission.

In the field, on the contrary, the effect of the environment must be assessed for each measurement, and the difficulty of determining the

field sound transmission loss (FSTL) will vary correspondingly.

Indeed, it is possible that problems raised by flanking transmission or by unusual field-test situation will make the measurement so difficult as to be impractical.

Evidently, there may be substantial difference between data obtained from similar elements in the laboratory and in the building, even when leaks and flanking transmission have been successfully eliminated. The factors that cause the difference in lab-field measurements will be discussed in more detail in the later part of this chapter.

source room receiving room

Fig. 13. Possible flanking paths in building structures, (on plan)

22 3.30 Field Measurements of Airborne Sound Transmission Loss in Buildings

3.31 Method of Measurements

The standards (Refs. 35, 39 & 43) describe a general procedure for

the measurements. This will be outlined briefly below. Some of the

requirements such as room diffusion, ambient noise level, etc. will

be dealt in greater detail, together with some of the associated

problems in field measurement, in the following sub-sections.

The field measurement method is similar to the laboratory method

except that the partition in question may not be the only

significant sound transmission path. The background noise is always

one of the major problems encountered while carrying out field

measurements. The background noise should be significantly lower

than the test sound in both source and receiving rooms. A level of

10 dB below the test level at all test frequencies is generally

considered as desirable (see Fig. 45). Problems may arise in cases

when the test wall sound transmission loss is high (assuming flanking

is at its minimum), in that the source level has to be raised to a

considerably higher level in order to attain the 10 dB difference.

Field testing can be catergorised into two groups, for compliance

with an acoustic specification:

i) where the noise reduction between two rooms is required

ii) where the sound transmission loss of the element in test

is required

The noise reduction between rooms can be expressed in the form of a

23 Normalised Level Difference in dB in the form of Dn or Dn(t) depending on the correction used. The equations are expressed as

Dn = Ll - l2 + 10 lo8lO(Ao/A) **-(1)

where and L2 are average sound pressure levels, in the source

and receiving rooms respectively, in dB 2 AQ is the reference sound absorption in m -sabins

A is the measured sound absorption in receiving room in

m^-sabins 2 and Aq is usually taken as 10 m -sabins and

Dn(t) = Lj. - L2 + 10 log10(T/To) ...(2)

where and L2 are the average sound pressure levels, in dB,

in the source and receiving rooms respectively

T0 is the reference reverberation time, in seconds

T is the measured reverberation time in the receiving room,

in seconds and T0 is taken as 0.5 sec. which is based on typical values in domestic dwellings. The values obtained (Ref. 15) include all sound transmitted by all possible paths.

Where the field sound transmission loss property of a particular element is required, the field sound transmission loss (FSTL)* is expressed as R' and

R' = Lx - L2 + 10 log10(S/A) ...(3)

* Note that R' is not mentioned in ISO R140 (Ref. 35) BUT appears in ISO R717 (Ref. 36).

24 where and L2 are the average sound pressure levels in source and

receiving rooms respectively, in dB 2 S is the area of the test element in m

A is the measured sound absorption in the receiving room in

m^-sabins

Most standards recommend that measurements should be made in 16 third-

octave frequencies. (ISO R140 and BS 2750 specify the third-octave

centre frequency range from 100 Hz to 3150 Hz, ASTM specifies the

centre frequency range from 125 Hz to 4000 Hz.) The source used could

be either a warble tone or white noise. ISO R140 specifies that

if a warble tone is used, the frequency deviation should

be at least ^ 10% of the mean frequency, at a modulation

frequency of about 6 c/s, except that for frequencies

above 500 c/s, a frequency deviation of + 50 c/s is

sufficient

if white noise is used, the measurements of the sound

pressure level in the source room and the receiving room

should be made with band-pass filters, of nominal width

1/3 or ^ octave*, with mid-frequencies equal to the above

values or sufficiently close to them to cover the frequency

range 100 to 3200 c/s adequately in 1/3 or ^ octave steps.

The discrimination characteristics of the filters should

be so chosen, in relation to the sound spectra to be

measured, that errors in the measured level difference

arising from the transmission of frequencies outside the

nominal band-pass should not exceed 1 dB.

* % octave frequency intervals are permissible under ISO R140 (Ref. 35) 25 3,32 Field vs Laboratory Measurement

In laboratory measurements of airborne sound transmission loss of a

specimen, the test specimen is inserted in an opening between two

reverberation rooma. The construction of these rooms is such as to

reduce to a minimum the sound transmitted by any path other than that

through the test panel. Ambient noise is hardly a problem. A diffuse

sound field is generated in the source room and since the receiving

room is reverberant, an approximation to a diffuse field will exist

there also. The sound pressure levels in both source and receiving

rooms are measured with omni-directional microphones in at least five

positions in each room. The sixteen values of sound transmission loss

(R) are then derived from the sound level differences by applying a

correction which takes account of the area of the test specimen and

the absorption in the receiving room, at each frequency, and the

sound transmission loss is given as

R = LL - L2 + 10 log10(S/A) ...(4)

All notations are as in equation (3)

In field measurements, as opposed to laboratory measurements, it is

not possible to determine a sound transmission loss for any part of

the building since the measured value is a summation of transmission

along many different paths. To obtain a complete room diffusion is

even harder. However, the values of sound transmission loss can be

obtained by relating the sound pressure level differences between

the two rooms with appropriate corrections, as described by equation

(3) in the previous sub-section. The basic differences between the

field and laboratory conditions are as shown in Table 5.

26 Table 5; Comparison of Conditions (After Kodaras and Hansen 1964)

Test Parameters Laboratory Field

Sound field Diffuse Usually non-diffuse

Flanking Known condition Variable transmission

Size of rooms Conforming to Usually too small standards 160 Hz & below

Ambient noise At least 10 dB Usually within 6 dB level below receiving or less in room levels receiving room

Sound absorption Less than 0.05 Measurable but with coefficient some question as to accuracy of data

It is expected that the field values (Rf) will be lower than the values

of the similar element obtained from a laboratory measurement (R). It

is suggested that an allowance should be made due to the presence of

flanking transmission in the field. Partitions having values of R up

to about 35 dB should give equivalent values of R' in the field under

normal conditions; where the value of R is greater than 35 dB and up

to about 50 dB, flanking transmission may account for up to about half

the total sound transmission, and the values of R* can be expected to

be from 1 to 3 dB lower than R, unless special precautions have been

taken to avoid flanking transmission (Ref. 44).

3.40 Factors That Cause The Inaccuracy of Results

Field sound transmission loss (FSTL) values are likely to be lower

than laboratory sound transmission loss (STL) value owing to the

accumulated effects of certain factors such as flanking, insufficient

27 or lack of room diffusion, leaks, assemblies differences and many

others, in the field. Kilman and Nilsson (Ref, 107) studied a

number of effects of the relation between laboratory room design and

partition mounting and accounted for some interlaboratory differences,

but they still concluded that for low frequencies the transmission

loss can vary appreciably even between classical laboratories.

Bhattacharya et al (Ref. 54) conducted a number of measurements and

concluded that the sound transmission property of an element is also

a function of the transmission measuring facility.

Kilman (Ref. 104) in an earlier paper, defined "precision" as "a

measure of the reproducability of the measurement", i.e. the

repeatability of measurement. The well documented differences

between laboratory and field measurements have put many investigators

in pursuit of the anomalies that reduce the accuracy of measurements

(Refs. 55, 60, 93, 99, 104, 107, 111, 140, 152 & 162). Basing on

laboratory results could lead to a wrong prediction of field

performance of a building element. Many associated factors should

be taken into account. Some of these associated factors will be

discussed in greater detail below.

3.41 Room Diffusion

All standards recommend that in order to carry out the airborne sound

insulation measurement of a specimen, the sound field of the two rooms

should be as diffuse as possible. Thus if the ideally diffuse sound

fields cannot be realised, the standard method of measurement will

have system errors, some of which are impossible to avoid (Ref. 104).

28 The condition of complete diffusion is quite difficult to obtain even in a specially designed laboratory; it is rarely obtainable in the field. Diffuse conditions are attained when a sufficiently large number of normal modes fall within the bandwidth of the measurements to overlap each other. At the lower end of the frequency range in domestic-sized rooms, there are typically 4 to 6 normal modes per one-third octave band and these cannot overlap continuously through­ out the band, even if they can be equally excited (Ref. 152).

Further, it is difficult to provide diffusing elements which are effective at low frequencies, say, around 100 Hz. It is therefore impossible to have normal domestic rooms approaching diffuse conditions at low frequencies, and thus an accurate measurement of sound insulation is also quite impossible (Ref. 104).

Higginson (Ref. 93) has reported that the measuring difficulties in domestic buildings are particularly severe because of the relatively small room sizes. He reported a series of transmission loss tests on a 230mm brick wall separating two dwelling-unit-sized rooms. He was in fact concerned with measuring techniques for airborne sound insulation, including both instrumentation and procedures as well as the test environment. He noted that when sufficient absorption was placed in the receiving room to obtain a reverberation time of about

0.75 sec., the transmission loss was 1.5 dB more than in the bare room condition. This may be due to distortions of the diffuse field condition, or there may be problems in obtaining adequately sampling if the absorption is high. Higginson took this as evidence that the elementary normalisation procedure is not fully justified.

Thus, there appears to be ample evidence that the test environment

29 effects exist in both laboratory and field testing. While diffusion

can be standardised or devised in a laboratory, it is rarely possible

in the field.

3.42 Effects of Flanking

It has been mentioned in Chapter one that sound travels from one

room to another in a more complicated way than just penetrating

through the direct primary path. Sometimes sound which travels

through other paths is just as important as the sound transmitted

through the partition i.e. the quantity sought is the sound

transmitted through all paths (see Fig. 13).

It is well documented that field conditions which exist, such as

flanking, can substantially reduce the sound insulation obtained for

a laboratory-rated partition. Kodaras and Hansen (Ref. 109) have

used the results obtained by a close microphone method proposed by

London (Ref. 115)* to enable the presence of a flanking path to be

recognised. Shiner (Ref. 162) showed that for a particular wood

frame structure using a modified balloon framing, the structure-borne

flanking under simulated field conditions limited the sound insulation

of a partition to an average field sound transmission class (FSTC) of

39. Jones (Ref. 100) has published data for field airborne flanking

through bathroom exhaust ducts that limited a floor with an estimated

laboratory sound transmission class (STC) of about 50 to a field

sound transmission class (FSTC) of 28.

But, it is also reported that under proper conditions of test and

partition installation, closer agreement between laboratory STC and

field STC (FSTC) can be obtained. Heebink, et al. (Ref. 90) showed

* Appendix 1 30 that for party walls the field value was, on the average, three points

below laboratory data for walls and one point below laboratory data

for floors. It is also stated that field performance can closely

approximate laboratory performance, unless serious oversights in

construction contribute to sound leaks or flanking. Another study

(Ref. 99) showed that in the absence of flanking or by taking into

account a flanking correction, field STC values for acoustically

sealed partitions can, under certain conditions of partition design

and test environment, exceed the field STC value predicted from the

laboratory STC value for replicate construction. But a suggestion

is made that evaluation of partitions under a range of field or

simulated field test environments would be desirable in the develop­

ment and characterization of partitions.

Flanking transmission is in fact a prime cause that may result in

large differences in sound transmission loss values obtained in

laboratory and field tests of building partitions. Unless the

problem of flanking is solved or minimised, the chance of getting

the field results to agree with laboratory results remain very slim.

3.43 Sound Transmission Through Windows, Doors and Other Installations

The measuring locations in buildings are usually selected in such a

way that sound transmission through windows and doors is as low as

possible. However, sound transmission through windows in two adjacent

or superposed rooms, and doors, has been investigated by Lang (Ref. Ill)

Lang reported that the presence of windows, either both closed, or

one open and one closed, have an effect in degrading the sound

insulation, especially when the air-tightness is inadequate.

31 The possibility of sound transmission through installations such as

ducts, water pipes, etc. is never taken into consideration in

laboratory measurements. In buildings, an important sound transmission

path is given by the ducts, cold or hot water pipes, etc. which

connect different rooms, for example, a heating pipe breaking through

the ceiling will reduce the sound insulation between two superposed

rooms or breaking through a partition will reduce the sound insulation

of two adjacent rooms. It is even reported (Ref. Ill) that the

fastening of one radiator to one or both sides of the wall has no

influence on the sound insulation of the wall, but a reduction of 3

to 10 dB at 1000 Hz was observed when two radiators on both sides of

a partition between rooms are connected with a 13 mm diameter, 15 cm

long iron pipe.

Obviously, the design and positioning of windows and installations

such as radiators, etc. greatly influence the sound insulation of the

building, and should be considered carefully, especially when higher

insulation is required.

3.44 Workmanship

Differences in sound insulation caused by different standards of

workmanship also occur, i.e. identical constructions constructed by

different work teams do not yield same value of insulation. The

difference may be negligible or as high as 10 or 20 dB (Ref. 111).

The difference may grow with the complexity of the construction, for

example, a simple brick or concrete wall may show insignificant

difference.

32 Ignorance of workmen with regard to importance of details of sound

insulation often results in insufficiency of sound insulation.

Unfortunately, making work simpler and cheaper on the site always

overrules the details shown in the drawings, unless stringent

supervision is imposed.

This discrepancy should not be allowed to perpetuate and certainly

it can be minimised or avoided if more specific requirements are

phrased in the specifications, and if architects, engineers and

craftsmen are provided with more information on the importance of

sound insulation.

3.45 Temperature Effect

How temperature can cause differences in sound insulation measurements

has been well reported by Scholes (Ref. 152) and Higginson (Ref. 93).

Scholes found that by heating either the source or receiving room,

different insulation values could be measured, particularly at low

frequencies. Higginson too, found similar results; with the rooms

empty, the measured sound insulation increases with temperature

difference but in the case of a heated receiving room the increases

are erratic.

The phenomenon is caused by mis-matching of acoustic modes of the

rooms, due to the difference in temperatures, when the rooms are of

the same geometry. Figs. 14-16 show the results of Higginson's

findings. Fig. 14 shows that the largest increases occur at low

frequencies, where the mode densities are lowest. Figs. 15 & 16

show the tendency for measurements to follow temperature difference;

33 loo zoo so o 1 ooo 2.000 aooo Frequency Hx 74- Effect of temperature difference. between meisorio^ rooms on difference---- source room located, receTvlob roow empty . TcmpCratun • • , 0*C A A , 5*3* C •, O O, 9*0*C ■, o-- - O , 15-0 *C- ; X X , ;

200 1000 frooo Frecpjency Hz. r<~6. . Effect of teipperAiure difference between measuring rooms on normalised level difference — receiving room heated and emptu. Temperature differences •. •—• ( 0°C ■, A------A ; 5-«'C ; O-—O , e-B’C i O...... O , 15*J°C ; X------X , 20-S*C .

200 5oo 1000 2ooo Frequency Hz. Fig. . Effect of temperature difference between measuring rooms on normalised level difference------source room heated, six absorbent panels In receiving room. Temperatun differences *. •------• , 0° C ) A------A, 5 • 4-* C ; o o , S* 3“ C. ; o...... o , 1(=>* o°C ; X------x , 13* o* C .

( After HF^^Iosoo , R. F=\, 1972 ) they indicate that the results are erratic, with unexpected variations

at individual frequencies. Also, Fig. 16 shows that when extra

absorption is introduced into the receiving room, the effect is

largely nullified, except at one temperature difference, i.e. at 19°C

difference. This again was predicted by Scholes (Ref. 152) and

results from the mis-matching (damping) of modes, already brought

about by the absorbent panels themselves, but the effect is still

significant.

3.46 Loudspeaker Arrangements

Kihlman (Ref. 104) concluded in his findings on the precision and

accuracy of sound insulation measurements that in airborne sound

insulation measurements the level difference between source and

receiving rooms is affected by the loud-speaker position and arrange­

ment in the source room and by the diffusing elements which may be in

the rooms but the dependence of loudspeaker arrangement and position

can be diminished if diffusing elements are put into the rooms.

Some comparison measurements based on different loudspeaker arrange­

ments have been reported by Higginson (Ref. 93). Twelve organisations,

some using two loudspeakers and some using only one, took part in the

measurements, in which three basic loudspeaker arrangements were used:

in a corner standing on the floor with axis horizontal and

at 45° to the two walls

in a corner with axis inclined at 45° to the floor as well

as the wall

in a corner, mid-way between floor and ceiling, with axis

again horizontal and 45° to the walls.

34 In all cases, the loudspeakers were positioned at a distance of 0.75m from the corner, with variations of with and without a back panel on the cabinets. In some cases, absorbent panels were added into the receiving rooms, the results of the investigation could be summarised as follows:

the arrangement of a single loudspeaker in an open-back

cabinet, set up in a corner of the source room mid-way

between floor and ceiling and relaying a band-noise signal,

generated more uniform sound pressures in the source room

at low frequencies, relative to those from other arrange­

ments tried. At higher frequencies the sound fields

generated by two selected loudspeaker arrangements became

more uniform, and the advantage of a particular arrange­

ment disappeared

in the source room, sound field uniformity was notably

affected by cabinet/baffle design. Loudspeaker size,

baffle orientation and signal level to the loudspeaker did

not appear to have any great influence on the sound fields

in the receiving room, no source room loudspeaker arrange­

ment gave notably increased uniformity of sound pressure

levels. Extra absorption brought about a small increase

in sound field uniformity at low frequencies. At higher

frequencies the introduced panels were more absorbent, and

thus caused considerable distortion of the sound field.

Their effect was then revered, and they made the situation

worse relative to the empty room condition.

The introduction of absorbent panels causes an increase in sound

35 insulation mainly at high frequencies (Fig.. 17) . The effect of the

panels is due in part to their influence on the uniformity of the

sound field in the room. Further, the panels induce mis-match between

the acoustic modes of source and receiving rooms (Ref. 93), that

results in an increase in the measured sound insulation.

3.47 Number of Microphone Positions

The accuracy of the measurements depends on the number of microphone

positions used. Statistical analysis (Ref. 17) shows that in order

to determine mean values to within 1 dB (90% confidence) in rooms

with low diffusion, at least 15 observations would be necessary at

low frequencies and 5 to 6 at high frequencies.

Again, Higginson (Ref. 93) has reported the results of measurements

using both normal free standing microphones and a moving microphone.

Figs. 18 & 19 show the differences between all three sets of measure­

ments are small. However, Higginson commented that such a close

alignment is considered fortuitous. He also found that using a

moving microphone rotating along a plane circular path is not very

satisfactory for sampling a sound field in which large variations of

level occur, it is perhaps better to use a traverse in both vertical

and horizontal directions.

3.50 Field Measurements of Impact Sound Insulation in Buildings

3.51 Introduction

In many practical applications of building acoustics, it is not only

the transmission loss for airborne sound that defines the conditions

36 18 . Level differences between source room and empty receiving room, 0------0 lar^e number of microphone positions -t o —o , small number of microphone positions ; x—x , moving microphone.

100 200 500 1000 2000 5"000 Frequency h Z FT6.19 . Level differences between source mom and receiving °absorbent panels. ®—o, lar£e number of microphone positu 0—---0 small number of microphone positions •, x-----X, movlr

(After Hi&Tnsoo, R- F., t972) that the occupants of a building have to live with, but also the impact noise isolation of the structure.

We can easily contrast impact noise with airborne noise, which is produced by a sound such as music, human voice, television or radio set. Inside a house, such airborne sound waves radiate outwards through the air until they strike a wall, floor or ceiling, which is set into vibration by the fluctuating pressure in the air. Because the wall vibrates, it radiates sound into the air on the other side, intruding the neighbouring room.

By contrast, impact noise is caused by a person or an object walking, falling or sliding on a wall or floor structure, such as footsteps, moving furniture, slamming doors, etc. and in all these cases, the floor or wall is set into vibration by direct impact or mechanical contact, and sound is radiated from both sides of the floor. For this type of noise, the surface of the floor is very important as regards to the amount of noise generated.

The most common source of impact noise in buildings is footstep noise on floors. Other severe noises may occur from time to time, but usually not often enough to constitute a significant annoyance. The increased number of multifamily dwellings using lighter forms of construction has motivated a considerable interest in the impact noise problem - the need to control impact noise has become apparent, to meet the occupants' demand of freedom from noise intrusion from neighbours.

The ISO tapping machine is the only impact test mechanism in common

37 use, but it has received serious criticism. In the following section,

the procedure of impact noise measurements using the ISO tapping

machine is described and this is followed by a discussion on the

validity of using the ISO tapping machine measurements for rating

the impact properties of floors.

3.52 Method of Measurements

ISO R140 (Ref. 35) specifies a standard tapping having five hammers

of specified size and mass equally spaced in line, the distance

between the two end hammers being about 400mm for the test of floor

impact sound reduction. The machine must deliver 10 impacts/second

at equal intervals, the time between successive impacts being 100

- 5 msec.

The impact sound reduction of a floor is found by setting up the

tapping machine in position and measuring the average airborne sound

pressure levels in the room below. The machine should be placed

successively in at least three positions. Measurements are made in

one-third octave frequency bands. ASTM (Ref. 37) requires all levels

to be expressed in third-octave band levels for the Impact Insulation

Class (IIC) single number rating to be derived. The ISO R717 (Ref. 36)

Impact Insulation (Ij_) rating is based on equivalent octave band

levels, thus, when the measurements are in one-third octave band

levels, 5 dB is added to each band level to convert the results to

octave band levels*. Normalised impact sound pressure levels (Ln) in

* if other bandwidths are used, the conversion is done by

L = L , + 10 log n dB oct 1/n oct 10

where Loct is the equivalent level for 1-octave bandwidth

L^/n is the measure level for 1/n-octave bandwidth

38 the receiving room in the specified frequency bands are computed

based on the following equation

Ln = L - 10 log10(Ao/A) ...(5)

where L is the average sound pressure level produced by the tapping

machine in the receiving room, in dB

A is measured absorption in the receiving room 2 and Aq is the reference absorption of 10 m -sabins

3.53 Criticisms on The Use of ISO Tapping Machine

There have been some serious criticisms of the use of the ISO tapping

machine as an impact sound source mainly due to its lack of similarity

to footstep noise. The sound levels produced are in fact much higher

than those due to footsteps, as it is designed to produce levels in

the receiving room that are sufficiently high above the background

noise level to give valid readings in the case of floors with high

performance. Unfortunately, impact sound is not well-defined; it

is produced by various activities, footsteps, children playing on the

floor, shifting furniture and many others. However, the sound all

results from direct contact between moving objects and the floor.

Despite the lack of similarity between the impacts produced by the

ISO machine and those resulting from footsteps, some researchers have

suggested that the machine is reliable for most floors that give

satisfactory results in practice. Olynyk and Northwood (Refs. 136 &

137) examined in the laboratory and in situ the correlation between

the sound level of a noise adjusted to mask the impact noise of

women's footsteps and the levels produced by the ISO machine. These

39 measures covered a very large number of different floors. The women

in the test wore high-heeled shoes with metal or hard plastic tips.

The masking noise was a random spectral noise with an NC 40 curve

shape, and the level was measured in dB(A). The above conclusion

was based on this comparison.

In contrast to the above workers, some researchers absolutely oppose

the use of the ISO machine for the following reasons:

the complete divergence between the impacts produced by

ISO machine and those resulting from the footstep

the non-linear behaviour of some floors and floor covering

may result in the floor being placed in a different rank-

order by the tapping machine as compared to subjective

impressions of the loudness of the impact sound transmitted.

These opponents to the ISO machine include Van den Eijk (Ref. 71),

Belmondo, et al (Ref. 47), Mariner and Hehman (Refs. 120 & 121), and

Watters (Ref. 181). These researchers decided to reconsider the

problem entirely, and have undertaken preliminary studies intended to

discover how to measure impact noises so as to ensure that the results

accurately reflect the disturbance’ caused. Mariner and Watters

consider that it is useless to measure the sound level of impact

noises since in the case of such noises, the important thing is to

discover the extent to which they stand out against the background

noise level. In this respect they are in agreement with Olynyk and

Northwood (Refs. 136 & 137) who based their investigation on masking

effect.

Between those who wish to keep the ISO machine (Refs. 136 & 137) and

40 those who want to have it radically changed (Refs. 71, 120, 121 & 181),

there is a third group of research workers which has proposed minor

modifications of the existing machine. Sven Lindblad (Ref. 114)

proposed that the ISO machine should be modified to give a better

simulation of the impact of women’s high-heeled shoes by reducing the

mass of the hammer to 0.2kg and the drop to 20 ram.

Since footsteps are the main impact noise generators in building, one

may ask why should the ISO machine not be replaced by a machine that

simulates footsteps. Unfortunately, the replacement of the tapping

machine by a footstep machine is not as simple as it looks. There

are so many types of footsteps: those of male, female, children and

adults; light and heavy footsteps. Which type is to be preferred

for the purpose?

3.54 Comments

Van den Eijk (Ref. 71) has pointed out the problems of replacing the

ISO machine:

what type of footstep is preferred?

not easy to get international agreement

sound pressure levels of natural footsteps are sometimes

so low that accurate measurements are hard to obtain. To

produce footsteps that are much heavier that natural will

result similar problems as those caused by the tapping

machine if the floors exhibit non-linearity.

Therefore, even though a footstep machine or Watters' mechanical

model (Ref. 182) were to be standardised for international use,

41 similar problems as with ISO machine will be encountered. What is

required is a new method which should be simple but reliable and

require less work and minimum time to test a floor or wall. Other­

wise, acousticians are going to remain as ’’people who change their

language about once every other year and thus are not to be taken

seriously" (Ref. 138).

3.60 Conclusion

The standard field methods for both airborne and impact sound

insulation measurements, though they are internationally recognised

and have a long case history behind them, appear to be inappropriate

for in-situ uses. Many investigators have proposed that some

alterations and even complete substitutions are required.

Unfortunately, most of the proposals are still in their infant stage

and could not be considered as finalised.

__*** ,— 4,00 SOME PROPOSED SIMPLIFIED METHODS OF MEASURING AIRBORNE SOUND

INSULATION IN BUILDINGS

4.10 Introduction

Many investigators (Refs. 45, 58, 73, 76, 77, 143, 147, 156, 157 &

163) have proposed that the traditional methods of determining a

single figure rating using ISO or ASTM procedures should be replaced

by simplified methods. These methods are criticised as very time

consuming, costly and too many measurements have to be taken in

order to compute the Airborne Sound Insulation Index, Ia (Refs. 35 &

36) or Sound Transmission Class, STC (Refs. 39 & 40). The A-weighted

sound-level-difference between the source and receiving rooms is

often suggested because the shape of the A-weighted transfer function

is very similar to the shape of the ISO or ASTM airborne sound

insulation reference curve. Siekman, et al explored aspects of A-

weighted-level laboratory tests which were to determine the Sound

Transmission Class. Schultz (Ref. 156) presented a case for this

simplified rating method for use in performance specifications for

building codes and showed that the simple difference in A-weighted

sound levels measured between source and receiving rooms, correlated

as well with judged privacy as the STC-rating when coupled with the

same additional parameters; within a range of typical sound spectra,

the correlation was not sensitive to the shape of the sound level

spectrum in the source room.

The degrees of correlation obtained by these authors are all very

high. Could it be due to the highly idealised cases employed (e.g.

when the room absorption was very constant over the whole frequency

range) that the remarkable results were yielded? Certainly many

43 questions need to be answered before the simplified method becomes

a viable rating method.

4.20 The Simplified Methods

4.21 Siekman's et al Proposal Method of Simplified Field Sound

Transmission Test

Siekman's et al (Ref. 163) simplified method of rating partition as

proposed, requires only two measurements, and the authors claim

that by using this method a dramatic amount of time can be saved,

curve-fitting can be eliminated and the results correlate well with

ASTM rating figure. The procedure and instrumentation are as

outlined below.

4.21.1 Source

A pink noise generator or a white noise generator with an adequate

filter to produce pink noise (equal energy per unit bandwidth ratio* -

equal energy in every octave) is the input source. A loudspeaker

with a 40 W continuous capacity capable of producing well over 100

dB(A) will be adequate.

4.21.2 Instrumentation

A simple sound lever meter with a standard A-weighting network,

capable of simple field calibration, and accurate to t 1 dB from

40 dB to 100 dB will be adequate.

* white noise - equal energy per unit bandwidth - energy increases 3 dB per octave ( see Section 4.23 p. 49).

44 4.21.3 Measuring Position at Source Room

For partition tests, the loudspeaker is located at about the third

point of the source room, facing away from the test panel and usually

aimed somewhat towards a distant corner of the room so that the test

specimen is not in the direct sound field of the speaker.

For floor-ceiling assemblies, the loudspeaker is located in the

room beneath the test specimen, but not aimed directly towards the

ceiling.

It is recommended in both cases to support the speaker housing on

some type of resilient pad to minimise direct structural excitation

of any part of the building.

Measurements are made, with slow response and A-weighting of the

sound level meter, at the one-third point along one of the room

diagonals, preferably at the third-point most distant from the

speaker and nearest the test panel as shown in Fig. 20.

In the case of measuring a floor-ceiling assembly, these authors

claim that the third-point near non-absorbent surfaces tends to give

more reliable readings. Therefore, if the floor is carpeted and the

ceiling is hard and reflective, the upper third-point should be

chosen, if the ceiling is acoustically absorbent and the floor is

hard, the lower third-point should be chosen and if both are

absorbent, the point nearer to the less absorbent surface should be

used.

45 4.21.4 Measuring Position in Receiving Room

The measuring point should be at a corresponding third-point

nearest the specimen, similar to the measurement in the source room

(slow response and A-weighting). The background noise level should

be at least 10 dB below the received noise level similar to that in

the source room.

4.21.5 Calculation

The simplified sound transmission class (SSTC) rating of a partition

may be determined from the difference between the dB(A) levels

taken from the two rooms, corrected for the sound absorption in the

receiving room, based on the equation:-

SSTC = LAs - LAr + 10 log(S/A) ...(6)

where L^g is measured level in dB(A) in source room

L^r is measured level in dB(A) in receiving room

S is the area of test panel

and A is total absorption in receiving room

Normally the reverberation times in the receiving room must be

measured to determine the room absorption. To avoid the tedious

work of measuring and analysis reverberation times at sixteen

frequency bands, Siekman, et al produce some approximate values

of absorption for typical domestic rooms as shown in Table 6.

Since the A-weighting network emphasizes the frequency region around

1000 Hz only, the absorption values for that frequency are

recommended to be used to simplify the calculations. Measurements

were made by Siekman, et al and they showed that the simplified STC

46 Table 6; Approximate Room Absorption in m -sabins

Frequency Hz 250 500 1000 2000

Bare, unfurnished 5.5 4.5 4.5 4.0

Carpeted, a few pieces of furniture 10.0 12.0 14.0 15.0

for bare rooms based on the above approximate room absorptions

gave higher rating values than for furnished room. Thus, they

advised that, for greater precision, actual calculations based on

actual measured absorption should be made.

4.22 Quindry and Flynn’s Proposed Method of Simplified Field Measurement

of Noise Reduction between Spaces

Quindry and Flynn (Ref. 143) have reported the results of their

extensive measurements of the noise isolation between spaces as

various types of signals were generated in the source room. The

noise reduction was determined by noting the difference in the

sound levels, measured with either the C- or A-weighting network

in both rooms. In this case the laborious method of measuring the

sound pressure levels in sixteen one-third octave frequency bands

can be avoided.

Quindry and Flynn observed that the noise reduction expressed by

(L£s - ) » whereas L^is the C-weighted sound pressure level in

the source room and L^r is the A-weighted sound pressure level in

47 the receiving room, gave a better correlation with Noise Isolation

Class (NIC)* or Ia rating than the (L^g L^_) sound level difference.

Unfortunately, many results are stated but not fully explained.

These authors went on to conclude that the source room noise

spectrum is very important and that the amount of absorption in the

source room can greatly affect the shape of this spectrum and thus

the correlation of the results. They further concluded that "a pink

noise source is preferable" however, when a pink noise source is

used the correlation of the data deteriorates as the source room

incorporates increased areas of absorptive materials. In order to

minimise the associated errors an absorbent source room should not

be used with a pink noise source, and better correlation is obtained

if both the source and receiving rooms have the same amount of

absorption.

4.23 Rettinger's Proposed Method of Simplified Field-Measured Sound

Insulation

Rettinger (Ref. 147) shows that the sound transmission class (STC)

of a partition can be determined fairly accurately by measuring the

C-weighted sound level in the source room and the A-weighted sound

level in the receiving room and then calculating the difference.

* Noise Isolation Class (NIC) ASTM E336-71 (Ref. 39) defines NIC as "if a single number rating of noise reduction is desired, it shall be Noise Isolation Class (NIC), determined as follows. For field situations where the noise reduction between a pair of rooms has measured in one-third octave bands, a single-number rating may be assigned to evaluate the acoustical isolation existing between these two rooms by applying to the measured curve of noise reductions the procedures of ASTM E413-73 (Ref. 40)". In short, it is based on the same principles as Sound Transmission Class.

48 His evaluation is based on two rooms separated by a partition of

known STC value (STC 30). Pink noise (equal energy in every octave),

red noise (energy decreases 3 dB per octave) and white noise (energy

increases 3 dB per octave) sources were used, and sound pressure

levels based on C- and A-weighting in both rooms were noted. Level

differences based on (L^s - ) and (L^g - ) were computed and

plotted in graphs and a pronounced correlation with Noise Isolation

Class (NIC) is discovered between the L^s and L^rvalues for all the

three types of noise. This leads to his conclusion that "C-network

in the sending room and A-network in the receiving room" is perhaps

the more accurate procedure but without specifying the source spectrum.

In the sound insulation measurement of a partition in the field, it

is necessary to include the room correction factor of 10 log];Q(S/A).

In this particular case, Rettinger assumed the correction factor as

zero to simplify the determination of the Noise Isolation Class (NIC)

rating of the partition.

4.24 Tricaud's Proposed Method Using Impulse Techniques for the

Simplification of Insulation Measurements between Dwellings

Tricaud of France (Ref. 170) proposes a method using pistol shots

to measure the airborne sound insulation between dwellings as well

as facade insulation for external noise.

The measurement is conducted in the following manner. A pistol

shot is fired in the source room. The acoustical pressures are

detected at the centres of the source room and the receiving room

by sound level meters. The signals are recorded on a tape recorder

49 and on replay filtered by octave filters. But the method of replay

(if the recording is reversed on replay) is not described and only

the tape recorders of "good quality" are to be used is mentioned.

From the residual signals Ps(t) for the source room and Pr(t) for

the receiving room, the following integrals are calculated:

...(7)

...(8)

where the duration of the pressure signal, T, is relatively short and depends on the type of source and the reverberation time of the source room.

The insulation for a particular octave can be written as:

Dfi = 10 log-^- dB ... (9)

Thus two integrals for each octave have to be calculated from the signals recorded so as to derive the insulation for all frequencies required. It is suggested that the integrals can be calculated either each of the following:

direct calculation by computer after digitalization

passage from time domain to frequency domain and

calculation of the power spectral density of the

signals after filtration

- analysis of the signals by a detector having a large

time constant, the signals having been previously

re-recorded on a new tape in order to have a continuous

loop

analogue integrator

50 Tricaud envisages that in future integration can be made directly

by two analogue integrators without the need of the signals being

recorded. But then one pistol shot is required for each octave

considered.

Comparisons of impulsive and classical methods of measurement sound

insulation are given for a number of dwellings and Tricaud claims

that the agreement is remarkable, with a standard deviation of 1.1 dB(A).

4.25 Van den Eijk's " 'My Neighbour’s Radio1 Theory"

Van den Eijk (Refs. 76 & 77) of the Netherlands theorised that

when in one's dwelling, it must be possible to

concentrate on mental work, without being disturbed

by a neighbour's radio

- when in one's dwelling, it must also be possible to

adjust one's radio, gramophone or tape recorder to

the level one prefers for good listening conditions,

without being afraid of disturbing the neighbours.

He conducted a series of experiments concerning mostly disturbances

caused by a neighbour's radio and/or television (Ref. 73), as he

believed radio or television programmes in general consist of the

sounds of normal life.

Radio music is often used as a general acoustic background in the

home whereas the television is generally turned on only when one is

watching the programme and it is also usually at a higher sound

level. But, during his investigation of the airborne sound insula­

tion between dwellings, the radio was turned on to the level

51 required for attentive listening and it was not based on the

general background radio level. Since his findings indicate that

the octave bands between 400 to 800 Hz determine the quality of

insulation between dwellings, he puts forward the question is there

any use in extending the measurements to frequencies below 400 Hz

and above 800 Hz? (see Figs. 21 & 22)

4.26 Schultz’s A-Level Differences for Acoustical Isolation Rating

Schultz (Ref. 157) based on Cavanaugh's et al (Ref. 62) and

Young's (Ref. 188) findings carried out some further analysis which

show that the correlation with judged privacy is just as good if the acoustical isolation between rooms is expressed not by the

Noise Isolation Class (NIC) or Sound Transmission Class (STC) but

by the difference in A-weighted levels. The correction is not

sensitive to reasonable differences in the spectrum used in the

source room for the tests. Schultz found that the sum of the A-

weighted Noise Reduction and the A-weighted background noise level

in the receiving room correlated even better with subjective

reaction than did Cavanaugh's or Young's indices for three different

noise source spectra (Refs. 62 & 188).

Schultz emphasizes that Transmission Loss alone is not a good

indication of sound isolation nor is the Sound Transmission Class

(STC). Noise Reduction is better indicator as it accounts for

flanking transmission paths as well as the receiving room absorption.

But still it is not a true indication for the acoustical isolation between spaces. Schultz proposes "Privacy Index" as a better

replacement, where the Privacy Index (Ip) is given as

Ala + na I P

52 whereas AL^ is the A-level difference between the two rooms

and N^.is the background noise level in A-weighting.

Of course, this is subjected to the condition that NA must not exceed

some maximum value, but the Privacy Index has the advantage that no

normalisation is needed to account for differences in receiving room

absorption.

Whether the A-level difference can detect the prominent undamped

coincidence dip in the noise reduction of a partition or whether this

is important or not is still not certain. But Cavanaugh et al (Ref. 62),

Northwood and Clark (Ref. 134) concluded, based on their experiments

that the coincidence effect is small and unimportant in assessing

human annoyance. In a more recent report, Stephens (Ref. 165)

confirms more generally that A-level differences do show up

deficiencies in isolation due to coincidence dips.

Schultz proposes the use of the A-level difference based on the theory

that since the ratings based on A-level difference (Ref. 143)

correlate well with the NIC ratings, there is no reason why the

complicated one-third octave NIC or STC evaluation should be employed.

But Schultz’s proposal does not convey the implication that all field

tests ofacoustical isolation should be made in terms of A-level

differences. The sophisticated one-third octave method may be used

for "diagnosis and remedial work" when the field determination of

which part of the structure causes the inadequate privacy is required.

4.27 Stephens’ Proposed Method of Measurements of Sound Insulation with

a Sound Level Meter

Stephens (Refs. 164 & 165), based on the great similarity between the reference curves used for airborne sound insulation (i.e. STC, HPWG,

53 ISO R717 reference curve) and the A-weighting curve (Fig. 23), proposes that the latter should be used as the reference curve for sound insulation measurements. Stephens mentioned that since the A- weighting curve is already internationally standardised for noise measurements, its adoption would make for a unification and rationalisation of acoustic criteria, i.e. there would be a firm theoretical basis for measurements with a sound level meter. Figs.

24a & 24b show the pitfalls of using the reference curves in rating sound insulation of building elements.

Stephens' method is in fact similar to Siekman's et al (Ref. 163) both in procedure and equipment except the following:

Siekman et al use the A-weighted scale for measuring the

overall sound level on both sides of the test wall and

Stephens proposes the use of linear scale on the source

side and A-weighting on the receiving side

Siekman et al use pink source and Stephens suggests white

noise based on the theoretical grounds that when the

received level is measured on the A-weighting network,

any serious adverse deviation of the partition below the

reference would be revealed by the higher received level.

Stephens names the level difference between the two rooms as DSLM.

To avoid further calculation and correction, he suggests a standard

O absorber could be used in an empty room such as 4 m of acoustic foam

But for a well-furnished and carpeted room a deduction of 3 dB, and for less well-furnished rooms a deduction of 2 or 1 dB is required.

Sound Insulation Measurements on a set of four walls were carried out with both the simplified A-weighted test and the standard test

54 Fiji. 23. Com-paWson of ISO 8-7/7 reference Curve, wrtb House 'Kv'ty Walt Grate, &wt wTtb tA’ we?gbtuo£ curve from 5fo dB dakim.

60

50

C 0

-40

-3

30 9

20

40 $mg§!S3S§g§S8§ gasSSSSiSSliilli Frequence} Hr

Fi'^.24. Extreme examples of sound reduction curves wtai'cb would be rated simi larUj, but lobido would be expected to coffer subjectiveUp left) TxJtb ccuves satisfying House "Party LUaU Grade, wHt, 23 dB -permitted adverse deviation. Cb: ngbt ) 3otb curved rated 1^ 52 aceordinJ> "to ISO "8.7/7, wltlj 32 dB permitted a££re£*te adverse deviation.

(Af-fen . 'b- A. /973j based on ISO R140 (Ref. 35). The results appear to correlate very

well with the uncorrected DSLM differing from Ia by only i 1 dB.

But the room absorption is not mentioned and presumably the rooms

were all unfurnished when taking the measurements.

4.30 Correlation between Simplified Methods and the Sound Insulation

Rating based on ISO or ASTM Recommendations

Siekman et al, were in fact one of the first* to suggest the simplified

procedure for estimating the sound insulation of walls and floors in

buildings. Later, many other investigators (Refs. 45, 48, 73, 76, 77, 143, 147, 156 & 157) emerged with their individual versions of

simplified methods of sound insulation measurements, but, it appears

that all of these proposals are similar to Siekman's et al simplified

procedure.

The availability and standardisation of a simplified test procedure

will in fact have a great impact on insulation assessment in buildings.

This should not be construed as intending the simplified procedure

to replace ISO R140 (Ref. 35) or ASTM E336-67 (Ref. 39), but as a

method of providing a simpler procedure to check building design

requirements in a more economical and practical manner. All these

authors show that their results, derived from their respective

simplified methods of sound insulation measurements, correlate

remarkably well with an ISO R717 or STC rating. Perhaps, due to the

limited number of case studies, the close correlation between these

* Gbsele, K. and Bruckmayer, F. (1965) published a paper "Proposal for Characterising the Airborne Sound Damping of Building Elements", (Gesundheits - Ingenier 86 No. 6, in German and no reference could be made) which appears to be the earliest paper calling for the use of simplified methods of airborne sound insulation measurements.

55 ratings must not be taken too seriously. However, to ascertain the practicability of Siekman's et al simplified procedure, Brittain

(Ref. 58) carried out an experimental evaluation in a laboratory, based on the following aspects:

validity and accuracy of using a single third point to

determine the sound pressure level

the capability of a single speaker at a third point,

with or without rotating vanes, to produce a diffuse

sound field in the source room

the overall accuracy of the procedure as compared to

the results obtained from ASTM E90-70 (Ref. 38).

Several conclusions are drawn based upon the results obtained, but it should be noted that great care must be exercised in the adoption of these conclusions as they are based on laboratory results.

Several of Brittain's conclusions and discussions are summarised and listed below:

1. Measurement of SPL at third point gives statistically

valid results.

2. The presence or absence of diffusers appears to have

little effect upon the result of A-weighted SPL

measurements.

3. The use of a single speaker at a third point appears

to produce a sound field sufficiently diffuse for the

purposes of a simplified test procedure.

4. The accuracy of + 2 dB for 95% of partitions tested

cannot be substantiated. Perhaps within + 6 dB as they

claimed for some partitions is more likely. Under field

conditions, a single third point measurement cannot be

56 expected to yield measurements with the above level of

statistical precision.

5. Lower frequencies appear to be a problem, as measurement

of a pink noise source with an A-weighted meter

effectively discounts the low frequencies.

Obviously, further experimental evaluation, particularly in the field,

of this and other simplified test procedures is urgently needed. It

is only through the measurement of field performance that more

realistic conclusions and recommendations can be derived.

4.40 Why dB(A)?

A single measurement such as dB(A) has the advantage of saving time

and expense in the assessment of noise, but inevitably contains less

information than an octave or third-octave-band frequency analysis.

This information, as many investigators (Refs. 87, 164 & 165) have

pointed out, however, is not needed for most practical purposes and

is more suited for research. Since the A-weighting curve is already

internationally standardised for noise measurements, its adoption as

a reference curve for sound insulation measurements would make for a

unification and rationalisation of acoustic criteria (Ref. 165).

Not only is it relatively simple to use, it has been found that the

dB(A) level possesses a good correlation with human subjective

response to noise (Ref. 87). Young (Ref. 189) too, showed that good

correlation with occupants' reactions can be achieved using A-levels

to evaluate background noise, and the Noise Isolation Class to

evaluate acoustical isolation. Schultz (Ref. 157), Burgess and

Harman (Ref. 61) have also indicated that single value rating system

57 for transmission loss using dB(A) difference are workable.

It is pointed out that the A-weighting is not suitable for measuring

all noises (Refs. 87 & 148). It cannot be used to accurately predict

the annoyance of narrow band noise or pure tones in the presence of

broad band noise. However, many noises, such as traffic noise and

noises in dwellings, are broad band noises for which this limitation

does not apply and thus they can be satisfactorily measured using

the A-weighting network of a sound level meter.

4.50 The Modified Laboratory

The simplified methods of measuring airborne sound transmission in

the field appear not to appeal to some research workers. In Britain

(Ref. 98), some research workers have used an acoustic test chamber

designed for the measurement of airborne sound insulation of party

walls using the classical 16-frequency test method.

The test chamber was initially developed as a research tool to over­

come the need to carry out field measurements on new dwelling types,

by constructing the chamber to simulate the new dwellings and having

all the possible flanking paths, via the external wall, the ceiling-

party wall junction and the floor-party wall junction.

Perhaps this method will work if all the dwellings are identical in

design and constructed under similar workmanship, otherwise the test

chamber will become obsolete as the dwelling design varies. A

limitation of this particular test chamber is that it represents only

a particular type of dwelling design, for instance, flanking behaviour

between single storey and two-storey structures are not the same.

58 Secondly, the method will have limited value unless the tedious and time consuming 16-frequency tests and analysis can be avoided.

Lastly, the ability of a chamber of this nature to provide a simple and economic means of assessing in the laboratory the airborne sound insulation of dwellings as claimed is in fact very doubtful.

— *** —

59 5.00 AIRBORNE AND IMPACT SOUND INSULATION REQUIREMENTS FOR DWELLINGS

5.10 Introduction

Many countries have their building codes and the obvious answer to

noise problems in dwellings is the enactment of noise control

requirements in the building codes. This includes the

Airborne Sound Insulation requirements

Impact Sound Insulation requirements

The requirements are commonly condensed to a single-figure number.

These single-figure ratings of airborne and impact sound insulation

have gained considerable favour among architects, builders and code

writers because of their simplicity. Their derivations are based on

the ISO R717-1968 (Ref. 36), ASTM E413-73 (Ref. 40) and/or ASTM

E492-73T (Ref. 41).

The methods of measurements for the airborne and impact sound

insulation have been discussed in Chapter three. The single-figure

ratings for airborne sound insulation and impact sound insulation

will be discussed separately in the following.

5.20 Airborne Sound Insulation Rating Systems

It is pointed out by Lawrence (Ref. 15 p. Ill) that ideally the

sound transmission of a building element would be individually

specified over the required frequency range to suit its particular

use. However, this would require the detailed knowledge of the noise

spectrum in the source room and of the spectrum of the acceptable

noise levels in the receiving room. In practice, it is found that

there is subjective acceptance of certain deviations from the ideal

60 sound transmission loss between rooms, and it is necessary to derive

a rating system that will not objectively penalise an element that

could well prove acceptable in practice.

Different countries have their respective building codes and their

own rating requirements, but they are all similar. The ISO and ASTM

methods of obtaining a single-figure rating have been widely used by

many countries in the world. The Sound Insulation Index (I„) as

specified in ISO R717 and the Sound Transmission Class (STC) as

specified in ASTM E413-73 have basically the same shape (see Fig. 25),

the only difference being that the former covers the range of one-

third octave bands with centre frequencies from 100 Hz to 3150 Hz

and the latter those from 125 Hz to 4000 Hz.

5.21 ASTM STC Rating System

The STC rating is based upon the test procedure specified in ASTM

E90-70 (Ref. 38) for laboratory measurements of sound transmission

loss. The STC of a partition or floor is found by comparing the

sound transmission loss curve, determined from one-third octave

band measurements made over the frequency range 125-4000 Hz with a

reference contour (see Fig. 25) on a transparent overlay. The

reference contour is shifted vertically relative to the test curve

to as high as possible while still meeting the following two conditions

1. The maximum deviation of the test curve below the

reference contour may not exceed 8 dB at a single test

frequency.

2. The sum of the deviations of the test curve below the

reference contour at all sixteen test frequencies may

not exceed 32 dB (i.e. not more than 2 dB average

deficiency per band).

61 Sound Transmission Loss 03 Impact Sound Pressure Level 63 Fig.

80 25.

100

Airborne 125 Impact

160 200 250

&

Reference Impact 315 one-third 500 400

Sound Airborne

Contour 630

octave Reference

Reference

band 1.25k

Contours frequency

Contour ~AlZf± 3.15k

Hz r

ASTM 70 45

dB dB

When the reference contour has been adjusted in this manner, the

STC is read from the vertical scale on the graph and is numerically

equal to the STL value which corresponds to the intersection of

the reference contour and the 500 Hz line (Ref. 40).

5.22 ISO Ia Rating System

Comparison is made between the reference contour (see Fig. 25) and

the field sound transmission loss R* over the 16 one-third octave

frequencies from 100-3150 Hz (Ref. 35) in the same manner as the STC

rating and complying with the following conditions:

1. The average deviation of the test curve below the reference

contour is greater than 1 dB but not greater than 2 dB.

2. The average deviation of the test curve below the reference

contour is less than 2 dB and the maximum deviation below

the contour at any frequency does not exceed 8 dB for

measurements made in one-third octave bands or 5 dB for

measurements made in one-octave bands.

The airborne sound insulation index Ia is the value of the reference

contour at 500 Hz when the above conditions are met. The standard

(Ref. 36) also specifies in alternative where the airborne insulation

margin Ma of A Ia can be obtained. Since the reference contour has

a rating of 52 dB,

Ma = A Ia = Ia - 52 dB

and Ma or Ala will be negative when Ia

5.30 Impact Sound Insulation Rating Systems

The most common system used for impact sound rating of floors is

based on the measurements obtained in the room below when the

standardised ISO tapping machine is operating. Measurements are

62 made in one-third octave bands, and normalised to a room absorption 2 of 10 m -sabins (see Section 3.52 p. 39).

5.31 ASTM/FHA Impact Rating Systems

The Impact Noise Rating (INR) is an old system which is based on the

procedure given in ISO Recommendation R140-Field and Laboratory

Measurements of Airborne and Impact Sound Transmission. The sound

pressure levels measured in one-third-octave bandwidths in the room

beneath the floor-ceiling structure on which the tapping machine is 2 operating are adjusted to a reference room absorption of 10 m . The

one-third-octave band levels are then increased by 5 dB to represent

the level that would result if full octave bands used (see Section

3.52 p. 38), and the resulting levels are then plotted against

frequency at one-third-octave intervals from 100 to 3200 Hz. The INR

is then determined be a comparison of this curve with a reference

contour (Fig. 26). The reference contour is adjusted vertically with

respect to the test curve to as low a position as possible such that

the following conditions are fulfilled:

1. The maximum deviation of the test curve above the refe­

rence contour may not exceed 8 dB at any single test

frequency.

2. The sum of the deviation of the test curve above the

reference contour at all sixteen frequencies may not

exceed 32 dB.

When the reference contour has been thus adjusted with respect to

the test curve, the INR value is determined by finding the octave

band sound pressure level that corresponds to the intersection of

the horizontal portion of the reference contour with the test curve

63 and subtracting it from 66 dB. The U.S. Federal Housing Adminis­ tration (FHA) has found that an INR of zero affords only marginally acceptable impact noise isolation. Positive values for the INR indicate better performance while negative values indicate poorer performance.

Some confusion has arisen over the fact that for airborne sound, high values for sound transmission loss and hence also high STC values mean that a partition provides a high degree of sound attenuation, whilst high values for impact sound rating because the transmitted noise is measured directly in the room beneath the floor, mean poor impact insulation. To alleviate some of this confusion, the FHA has developed a new single-number rating system for impact noise isolation called Impact Insulation Class (IIC).

The Sound pressure level measurements, made at 16 frequencies between 100 and 3200 Hz in one-third-octave bands in the room beneath the floor-ceiling structure on which the tapping machine is operating 2 are normalised to a reference room absorption of 10 m and plotted against frequency. The resulting test curve is then compared to a reference contour again by means of transparent overlay, and the reference contour is positioned vertically relative to the test curve to as low a position as possible such that the following conditions are fulfilled:

1. The maximum deviation of the test curve above the reference

contour may not exceed 8 dB at any single frequency.

2. The sum of deviation of the test curve above the reference

contour at all sixteen frequencies may not exceed 32 dB.

A new vertical scale is drawn on the right-hand side of the graph

(see Fig. 27). Values on the new scale decrease with increasing

64 one-third-octave band sound pressure levels, and the two scales

coincide only at 55 dB. To determine the IIC of the test structure

one finds the value on the right-hand vertical scale that corresponds

to the intersection of the reference contour and the 500 Hz line.

Higher IIC values mean better better acoustical performance, and in

very general terms, equal numerical values for IIC and STC imply

roughly equal insulating properties for impact noise and airborne noise

5.32 ISO I£ Rating System

The normalised impact sound level L nis obtained by employing the

procedure given in ISO Recommendation R140, in one-third-octave band

frequencies over the range of 100 to 3150 Hz (see Section 3.52 p.38).

5 dB is added to each level to obtain equivalent one-octave band levels 2 Normalisation is made to room absorption of 10 m , similar to that for

INR or IIC rating. Comparison is made with the reference contour

(Fig. 25) till the following conditions are met:

1. The average deviation of the test curve above the reference

contour is greater than 1 dB but not greater than 2 dB. '

2. The average deviation of the test curve above the reference

ontour is less than 2 dB and maximum deviation above the

reference contour at any frequency does not exceed 8 dB for

measurements made in one-third-octave frequency bands and

not exceed 5 dB for measurements made in octave frequency

bands.

(Note that the lower the reference contour below the test

curve, the better the floor is.)

The impact sound index 1^ is the value of the reference contour at

500 Hz. Again the impact protection margin or -A 1^ (Ref.36)

65 is given as

M± = -All = -(Ii-65) dB

A Ii is positive when I-^

Ii^> 65, i.e. unfavourable.

5.40 FHA Recommendations

The U.S. Federal Housing Administration has recommended airborne and

impact sound insulation criteria for partitions separating dwelling

units in multiple family dwellings, and these are set forth in the

FHA's very comprehensive report, "A Guide to Airborne, Impact, and

Structure Borne Noise Control in Multifamily Dwellings" (Ref. 30).

These criteria were developed for three different grades of housing

which are distinguished from one another chiefly on the basis of the

night-time background noise levels.

Grade I : is applicable to suburban or quiet urban residential

areas where the exterior night-time noise levels are

35-40 dB(A), and recommended interior noise levels lower

than 35 dB(A). These criteria are also applicable to

dwellings units above the eighth floor in high-rise

buildings and to the better grade or ’luxury' class

apartments.

Grade II : covers the largest group of apartments since it is

applicable to suburban and urban residential areas

which have average night-time exterior noise levels

of 40-45 dB(A) and recommended interior noise levels

of 40 dB(A) or lower.

Grade III : criteria provide only minimal acoustical privacy and

should be considered only for certain noisy locations

66 FT£. •So-nod "Pressure Level d6 Fig.

26> d£>

and party 27. .

1NP Impact C floors

2 O FHA')

FHA wall

£! UN

=

i

o, in sound construction 'Recommended a

terms octave normalised

s

level u

of 500 band

m

lie rating

to Sound

terms centre numbers *■ O o o Frequency

RT

1 0OO N ir\ r O

curve,

«•

r 10 O o

Insulation

of 0.5 frequency o (N o o

o .

STC

N 1(1 o sec.

Hz K) - o in 2000

i O o o numbers

for Hz

Impact Sound Iosu where the exterior night-time noise level is 55 dB(A)

or higher, and interior noise environment in the order

of 45 dB(A) or higher.

The fundamental criteria for airborne and impact sound insulation of wall and floor-ceiling assemblies which separate dwellings units of

equivalent function are given in Table 7. Tables 9 and 10 show the

recommended STC and IIC values for partitions separating different

functional spaces within a building. Table 8 shows the recommended

sound insulation for partitions in the same dwelling (not between

different apartments). Of particular importance is the fact that

these criteria are based upon STC and IIC ratings derived from the laboratory measurements rather than the field tests, and the criteria are merely recommendations, not requirements.

Table 7 Fundamental Criteria for Airborne and Impact Sound Insulation of Partitions Separating Dwelling Units of Equivalent Function (see Fig. 27)

Grade I II III ,

Wall Partitions STC 55 STC 52 STC 48 Floor-ceiling Assemblies STC 55 STC 52 STC 48 IIC 55 IIC 52 IIC 48

Table 8

The recommended sound insulationl for the partitions in the same dwelling (not between different apartments) is as follows •

Partition between rooms Grade I Grade II Grade III

STC STC STC Bedroom to bedroom 48 44 40 Living room to bedroom 50 46 42 Bathroom to bedroom 52 48 45 Kitchen to bedroom 52 48 45 Bathroom to living room 52 48 45

67 Tabic 9 Criteria for Airborne Sound Insulation of Wall Partitions Separating Dwelling Units

Partition Separates SIC

Apt. A Apt. B Grade I Grade II Grade III

Bedroom from Bedroom 55 52 48

Living room from Bedroom' 57 54 50

Kitchen from Bedroom 58 55 52

Bathroom from Bedroom 59 56 52

Corridor from Bedroom 55 52 48

Living room from Living room 55 52 48

Kitchen from Living room 55 52 48

Bathroom from Living room 57 54 50

Corridor from Living room 55 52 48

Kitchen from Kitchen 52 50 46

Bathroom from Kitchen 55 52 48

Corridor from Kitchen 55 52 48

Bathroom from Bathroom 52 50 46

Corridor from Bathroom 50 48 46

Table 10 Criteria for Airborne and Impact Sound Insulation of Floor-Ceiling Assemblies Separating Dwelling Units

Partition Separates Grade 1 Grade II Grade III

Apt. A Apt B. STC I1C STC I1C STC I1C

Bedroom above Bedroom 55 55 52 52 48 48

Living room above Redroom 57 60 54 57 50 53

Kitchen above Bedroom 58 65 55 62 52 58

Family room above Bedroom 60 65 56 62 52 58

Corridor above Bedroom 55 65 52 62 48 58

Bedroom above Living room 57 55 54 52 50 48

Living room above Living room 55 55 52 . 52 48 48

Kitchen above Living room 55 60 52 57 48 53

Family room above Living room 58 62 54 60 52 56

Corridor above Living room 55 60 52 57 48 53

Bedroom above Kitchen 58 52 55 50 ' 52 46

Living room above Kitchen 55 55 52 52 4S 48

Kitchen above Kitchen 52 55 50 52 46 4S

Bathroom above Kitchen 55 55 52 52 48 43

Family room above Kitchen 55 60 52 58 48 54

Corridor above Kitchen 50 55 48 52 46 48

Bedroom above Family room 60 50 56 48 52 46

Living room above Family room 58 52 54 50 52 48

Kitchen above Family room 55 55 52 52 48 50

Bathroom above Bathroom 52 52 50 50 48 48

Corridor above Corridor 50 50 48 48 46 46 While the United States does not have a national building code, the

FHA has adopted construction standards with which builders are

supposed to comply in order to qualify for FHA insured mortages. For

multiple-family dwellings, these standards are set forth in the FHA’s

Minimum Property Standards for Multifamily Housing (Ref. 31). These

minimum property standards contain no requirements for impact noise

isolation. The requirements for airborne noise insulation between

dwelling units are given in Table 11. Though these so-called require­

ments are included in the standard, they are not neccessarily mandatory.

Table 11 Requirements for Airborne Noise Insulation Between Dwelling Units Specified in FHA Minimum Property Standards for Multifamily Housing.

STC Low Background Noise High Background Noise Location Location^

Bedroom Other Rooms Bedroom Other Rooms Partition Adjacent to Adjacent to Adjacent to Adjacent to Separates Partition Partition Partition Partition

Living unit fron living unit 50 45 45 40 Living unit from corridor 45 40 40 40 Living unit from public space 50 50 45 45 Living unit from service areas 55 55 50 50

1. For buildings with all-year air conditioning and for dwelling units located above the eighth floor in high-rise buildings, the columns for low background noise should be used.

5.50 Some Notes on Single-figure STC Rating

Both Northwood and Clark (Refs. 64, 132-134) indicate that the Sound

Transmission Class is a useful rating system* for common architectural

* Clark (Ref. 64) also reported the pitfall of STC rating that two walls could be rated with same STC value though their sound transmission loss curves may be very much different.

68 problems. Subjective study of the STC system for rating building partitions was carried by these research workers and they concluded

that the change in subjective rating as a coincidence dip increases in depth is rather small (Ref. 64 & 134).

Figs. 28-30 show the comparisons between the inverted STC contour and speech, music and vacuum cleaner annoyance ratings respectively.

Figs. 28 and 29 give very good agreement except in Fig. 30, they are large discrepancies from the inverted STC contour. However,

Clark argued that since speech and music are the most important types of signals in sound insulation problems in dwellings, the STC contour shape is a good choice to use in rating the acoustical performance of walls.

However, the ISO R717 airborne sound insulation rating curve is itself faced with some criticisms. ISO R717 is intended for comparison rather than the ultimate objective rating of sound insulation. Unfortunately, all the rating systems available at the moment all have identical shapes to that of ISO R717. Stephens (Ref. 165) regards the present ISO R717 as not finalised with the following:

- The method of correction should be based only on S/A, which would

be applicable to both field and laboratory measurements.

- The reference curve should be replaced by the A-weighting curve.

- The Sound Insulation Index Ia read from the intersection of

the reference curve at 500 Hz ahould be replaced by 1^ as read

at the intersection of the reference curve at 1000 Hz which

is the international standard reference frequency.

- The curve fitting should be based on the condition that (a) no

adverse deviation is permissible in the frequency range of

69 i i i i i r

60 - FfS. 2& . One-tHird octave band 50 - 6levels of speed? #vio6 equal \ annoyance. The solia Woe 40 - represents an Inverted STC contour.

30 - (after Clark, a?. M.. 1970)

125 250 500 IK 2K 4K Frequency Hz

1 T I r

60 - a . 29 . One-third octave band levels of mu6ic £ivfn6 e^ual 50 - annoyance. TV>e solia Hoe represents an Inverted STC AO - com our.

30 - A. (After Clark. D. M., 197o ) A

125 250 500 IK 2K 4K Frequency Hz

80 - i i i i i r

70 - fid. 30 Ooe-tb!r'd octave bands 60 - 6of vacuum-cleaner noi6e giving ec^ual annoyance. The solta Hoe represents an Inverted STC 50 - contour.

40 - (After Clark, D.M., 1970)

30 - 425 250 500 IK 2K 4K Frequency Hz 400-1250 Hz, (b) a maximum of 5 dB adverse deviation is

permissible in other one-third-octave bands (for subjective

significance), (c) the total adverse deviation should be less

than 10 dB. He seems to disgree slightly with Northwood's

findings (Ref. 133). Northwood proposed that there should be no

deficiencies below the middle segment of the STC curve, but

deficiencies averaging 1 dB are allowed below other segment

of the curve.

There are also some critics of the use of STC rating for building boundaries. Rettinger (Ref. 146) observed from his finding that the typical STC curve is lacking in low frequency insulation when it is applied to exterior boundries.

In Fig. 31, the top curves show the spectrum of a passenger automobile and of a jet aircraft, labeled A and B, respectively. Both noises, measured outside the building, have the same sound level of 80 dB(A).

------£TC - 42.

Fig.37 . Required sound -transmission los6 characteristics (&-c) and Cfk) ■for barriers exposed to car di’o C*) -and Jet arrocaTt noi6e Cft) when the. d«6ired ibteroaf noise spectrunq is UC-3S . tAfter RettibAer, M., ^74-)

3| 5 4,3 125 250 500 /K 2K AH 6K m/d-frequencies of octave band flz.

70 The dotted curve represents a frequently recommended noise level

characteristics for the rooms of a home of NC-35. By substracting

this curve from the car and jet noise spectra, the required sound

transmission loss characteristics compensated by the room correction

factor of the building boundaries can be obtained. The solid line

represents the STC-42 contour, which, below 250 Hz, barely matches the

required insulation characteristics for the building boundary which

is to lower the external jet noise to the desired interior criterion

of NC-35. However, STC-42 does not, below 250 Hz, at all meet the

requirements for the sound attenuation of the building boundaries

intended to shield its inhabitants adequately against car noise.

Nevertheless, it shows that a higher STC rating is neccessary for the

boundaries to protect its dwellers effectively against the vehicular

traffic disturbances, which are richer in components below 250 Hz than

are contained in the jet noise. Therefore, Rettinger suggested that

possibly two contours should be developed, one for interior and the

other for exterior walls.

5.60 The True Value of STC

It is specifically noted in ASTM E413-73 (Ref. 40) that the single­

figure rating is devised only for the purpose of comparing partitions

for general building design purposes. The rating is designed to

correlate with subjective impressions of the sound insulation provided

against the sounds of speech, radio, television, music and similar

sources of noise in dweeling (and in offices). Thus, other means

such as Rettinger (Ref. 146) and Northwood and Donato (Ref. 135) have

proposed should be used for rating building boundries.

5.70 Airborne Sound Insulation Requirements for Dwellings in New South Wales

Australia, like many other countries, does not have a national building

code. It was not until 1974 that New South Wales enacted some sound

71 nsulation requirements for dwellings, incorporated in the State building code Ordinance 70 (Ref. 34). These apply mandatorily only * to Class II buildings having a rise of three or more storeys. Where a Class II building has a rise of not more than two storeys, the provisions of the Ordinance may be required by the relevant Council

Authorities. The condensed requirements are as shown in Table 12.

Table 12 Airborne Sound Insulation Requirements for Class II Buildings in NSW.

Walls: STC

walls dividing a bathroom, laundry or kitchen in one flat from a habitable room (other than a kitchen) in an adjoining flat. 50

wall dividing separate flats or a wall dividing a flat from a plant room, lift shaft, stairway, public corridor, hallway or the like. 45

wall separating soil and wastepipes from: -habitable rooms other than kitchen 50 -kitchen 30 -all other rooms 30

Floors: floor dividing separate flats 45

Like the FHA recommendations, all STC ratings in the Code are based on laboratory test results, but there is no provision for field measurements to be made to determine conformance. Furthermore, the provisions of the Code do not apply to single or attached dwellings

External noise intrusion and impact noise problems such as slamming doors and footsteps noise are not included in the Code.

* Class II Buildings: Buildings containing two or more flats.

72 Good acoustical performance of a building element in the laboratory

is no guarantee that it will provide the desired sound insulation in

the field. Because so many factors can adversely affect the acoustical

performance of a building element when it is installed in a building,

the importance of the inclusion in a building Code a provision for

field test is readily apparent.

5.80 Conclusion

The obvious answer to obtain the desired quiet home environment is the

enactment of noise control requirements in the building Codes. In

addition to enacting comprehensive building Codes, governments should

take other steps to reduce noises in homes and apartments. Home

appliance and building equipment manufacturers could be required to

provide sound power ratings of the products they market. Maximum

sound power ratings for certain types of equipment, such as food

mixers, washers, driers, dishwashers, and window air-conditioners,

could subsequently be incorporated in building Codes.

Much more can and urgently needs to be done to control noise from

outdoor sources. Often the growth of industry and road traffic is

so fast that there is a failure to provide a satisfactory acoustical

environment for neighbouring residential areas. Legal action should

place more restrictions on noise generated within the residential areas

itself, e.g. stringent noise performance standards along with the

limitations on the sound power levels of equipments such as land

mowers.

Control of noise, both indoor and outdoor, in residential areas clearly

demands a program and a coordinated approach to the problem from

73 builders, city planners, transportation system designers, and legisla tors. Furthermore, if significant progress toward this goal is to be realised, responsible individuals in city planning, transportation system design and planning, building departments, and enforcement

agencies must be given some training in acoustics and noise control.

Inadequate knowledge among public officials is presently one of the greatest impediments to a quiet environment.

•kick __ 6.00 FIELD SURVEY OF THE SOUND INSULATION WITHIN AND BETWEEN DWELLINGS

6.10 Introduction

The survey was carried out to investigate the sound insulation

characteristics of partitions and floor-ceiling assemblies within

selected dwellings as well as the party walls between dwellings.

The aims of the survey were first to investigate the performance of

typical walls and floor constructions in dwellings, second to inves­

tigate the validity of the simplified method of testing Sound

Transmission Loss of building elements in dwellings and third to

recommend a realistic method which could be included in Building

Codes to obtain effective regulation of sound isolation in dwellings.

At the same time, the discussion may include some of the results*

obtained on the measurements of the insulation characteristics of

concrete party floors of New South Wales Housing Commission high-

rise flats (Appendix 6).

The sound insulation measurements described were made on:

a. a basic timber stud partition consisting of a layer of

plasterboard on each side, having equal thickness and

density and no infill of absorbing material in the

cavity between the plasterboards;

b. cavity brick party wall between dwellings, cement rendered

on both faces;

c. timber floor-ceiling assemblies between rooms within a

dwellings.

& Office memorandum

75 All measurements were made on conventional brick-veneer houses,

either single or semi-detached and are described as Test No. 1

(New South Wales Housing Commission design) and Test Nos. 2 and 3

(home builder design).

6.20 Preliminary Survey

Many problems were encountered during the early stage of investigation.

Most of the Housing Commission houses are located in the outer suburbs

of New South Wales and finding houses in the private sector was a

little difficult. Many builders, including the Commission's builders,

who were approached were not very willing to release the houses

before the handover stage for the sound insulation tests. Their

lack of appreciation of sound insulation and lack of confidence in

their performance was one of the greatest impediments to the investi­

gation. Perhaps in years to come, when sound insulation tests have

formed part of the performance requirements in the building specifi­

cation, then these impediments will be eradicated.

Another alternative to guarantee results is the direct approach to

the owners of the houses who are psychologically keener to allow

their houses to be tested. But, another difficulty is that, not

unreasonably, the owners are keen or ready to move in once the

buildings are completed, thus the time between completion and

occupation is likely to be too short to make proper pre-arrangement

to carry out sound insulation tests. However, this difficulty could

be eased with proper planning when the construction is approaching

the completion stage.

Once the builders or the owners granted permission for the tests,

the next stage was to inspect the building plans in order to determine

76 the room arrangements which were suitable for testing. As a

general rule, tests should be carried out only when certain conditions

are satisfied, that is, where the common wall (or floor) area is 2 not less than 10 m and has a minimum dimension of not less than 3 2.5 metres; room volumes in no case should be less than 50 m (Ref. 35).

Moreover, the sound transmission test will be meaningless unless the

party wall or floor is common to both rooms. However, of all the

buildings selected for the sound insulation tests, none completely

satisfied these conditions. Many houses nowadays are designed with

small room sizes, which not only make measuring difficulties more

severe, but also depart from the above conditions.

It was originally intended that as many as possible measurements be

made on Housing Commission designed attached dwellings, where full

appraisal of sound insulation both within and between dwellings

could be made. However, the number of walls and floors tested have

been limited by the classical method used. Secondly, due to the

distant locations of these houses, to arrange for a re-visit was

not easy.

Only two walls could be tested in the Commission dwellings which are

described in Test No. 1 (Fig. 34). Test NoS. 2 and 3 were carried

out on two detached houses with identical design built by the same

private home builder, with the permission of the owners (Figs. 35

& 36). All measurements were made on the upper floors of the

selected dwellings.

6.30 Measurements

All the tests in the present survey were carried out in newly

constructed dwellings before occupation. The airborne sound

77 insulation tests were conducted to the recommendation of the Draft

Australian Standard for Field Measurement of The Airborne Sound

Isolation Provided by Building Elements (Ref. 33). Full sound pressure level differences of all sixteen required frequencies were obtained on site with a Briiel & Kjaer High Speed Level Recorder Type

2305 (Fig. 32), (in actual fact 18 test frequency differences, namely

from 50 - 5000 Hz were recorded on site) and the results were corrected to 10 log^ (S/A) (see Equation 3 p. 24 & Appendix 3).

Pistol shots in the receiving rooms were recorded on a Nagra IV SJ

tape recorder and the reverberation times at each test frequency were later analysed in the laboratory. In the source room, two AMI

Jorgen 40-W loudspeakers facing the corners and away from the test wall radiating a pre-recorded, filtered white noise source with centre frequencies at one-third octave intervals were used.

For the Impact Sound Insulation tests, the standard ISO tapping machine was used and the measurements were conducted to the recommendation of ASTM E492-73T (Ref. 37). Using the above described procedure, the sound pressure levels of all test frequencies for both source and receiving rooms for all the three recommended tapping machine positions at the centre of the room, namely one in alignment to the room diagonal, one parallel to the floor joists and one perpendicular

to the floor joists (Fig. 33) were recorded by the level recorder.

Though both the sound pressure levels in the source and receiving rooms were available, only the sound pressure levels in the receiving rooms were required in this particular test and were normalised to 2 10 m (see Appendix 4 Fig. A4.c).

Fixed microphone positions were used to record the level differences between the source and receiving rooms. Since most of the room sizes

78 were rather small, three to five random microphone positions were

used. Checking the response of the microphones was carried out

prior to the sound transmission tests by placing the two microphones

facingeach other approximately 15 mm apart (see Plate 1). Using the white noise as the source, the responses of all the required test

frequencies were recorded on the level recorder, for any neccessary adjustments to the test results (see Appendix 4 Fig. A4.a). During

the sound insulation tests, a level difference of at least 10 dB between the background noise and the test frequencies as recommended by the standard was adhered to. (See Fig. 45).

Besides the classical method, a simplified method of airborne sound insulation tests based on Siekman's procedure (see Section 4.21 p. 44) were carried out. Only one loudspeaker placed at two-third distance from test wall was used, and a Brtiel & Kjaer Type 2203 sound level meter was used to read both linear and A-weighted sound pressure levels at the major room diagonals one-third distance from the test walls, both in source and receiving rooms. (See Fig. 20).

In all cases, in both the classical and simplified methods of air­ borne sound insulation tests, the smaller rooms of the pairs were used as the receiving rooms because they possessed lesser absorption

(Ref. 75).

In the case of sound insulation tests for the concrete floors between dwellings in the NSW Housing Commission flats (Appendix 6), a similar test procedure as for the detached and attached dwellings was employed, except the sound pressure levels for both airborne and impact sound insulation tests at all required test frequencies in both the source and receiving rooms are read direct from a Briiel & Kjaer Type 2203 sound level meter with a Bruel & Kjaer Type 1616 third-octave band 79 filter attachment. Correction to the test results were made as

required.

6.40 Presentation of Results

Two sets of results were obtained from the tests, one from the

classical method of measurements and the other from the simplified

method of measurements. All workings and computations are included

in Appendix 3.

All the results derived from the classical method for Test 1-3 (Figs.

34-36) for both airborne and impact sound insulation measurements are

shown in Figs. 37-45 and the results derived from the simplified

method of measurements are shown in Tables 13-15. Comparison with

test results of similar construction carried by FHA (Ref. 30) and

EBS (Ref. 21) and standard deviations* of test results are also

included in Tables 16 & 17, and furthermore, standard deviations of

all test frequencies are plotted in Fig. 46.

6.50 Discussion of Results

6.51 Malls

Figs. 37-39 indicate that the field sound transmission loss curves of

the stud partitions tested have a great similarity to those of

laboratory test of like constructions (Ref. 186), having prominent

low frequency mass-spring-mass resonance phenomena and high frequency

coincidence. comparison with FHA (Ref. 30) and EBS laboratory results

(Ref. 21) are made in Table 16, showing that of all the seven walls

tested, one wall is about 9 points below that of FHA and 7 points

* Appendix 2

80 below that of EBS, one wall is about 8 points below that of FHA and

6 points below that of EBS, two walls are 5 points below that of FHA

and 3 points below that of EBS and three walls are 4 points below

that of FHA and 2 points below that of EBS. (Note: due to no

direct laboratory test counterpart, EBS result based on 5mm hardboards

lined on both sides, as indicated in Table 16 is used.)

It is expected that field test results are not strictly comparable to

laboratory results for the reasons that are mentioned in the previous

chapters. The discrepancy indicates the amount of flanking and lack

of diffusion which exists during the field tests. During the tests,

a comparison was made between the sound transmission loss when the

gaps under the test room doors were and were not sealed. As the

results showed no substantial change in transmission loss, it could be

concluded that sound could possibly flank through the side walls,

floor and ceiling space, as no barrier was erected in the ceiling

space to effectively separate the two adjoining rooms.

Even with a similar type of design, identical partitions will not

necessarily yield a similar STC rating. It is clearly indicated in

Test 2 and 3 that though the two dwelling designs are identical,

wall 2 in Test 3 yields STC rating 4 points lower than its counter­

part in Test 2 (Table 16). However, the conclusion can be drawn that

a wall of such design with a proper construction performance should

be capable of attaining an average STC rating of 32, with a standard

deviation of approximately 1.5-2.0 dB. Though there are no specific

sound insulation requirements within a detached dwelling in any of

Australian building codes, comparisons can be made with the FHA

recommendation for the STC rating between bedrooms (Table 8 p. 67).

81 At least another 8 points are needed to upgrade the results in order

to match the FHA recommendation of STC 40 for a partition between

bedrooms in Grade III construction and another 16 points are needed

for Grade I. If these recommendations were to be adopted in the local

building code, besides the control of flanking, some sort of absorbent

infill in the cavity and/or increased mass of the linings of the

timber partition would be required.

The 270mm cavity brick party wall shows an STC value of 49 which is

similar to the FHA's (Ref. 30) field result of similar construction.

Generally, STC values that exceed 45 are considered as satisfactory

and acceptable in multifamily party walls or floors (Ref. 32).

However, FHA has also conducted field tests on similar walls without

wall ties and the result shows that the STC value may increase from

49 to 54.

6.52 Floor-ceiling Assemblies

There is no direct laboratory test counterpart that could be used for

comparison with the field results. However, the results obtained,

both for airborne and impact sound insulation of timber floor-ceiling

assemblies, correlate very well with the FHA's (Ref. 30) field results

of similar construction (Table 17).

6.53 Comments on Accuracy of Measurements

It is not sufficient to know the value of the insulation of a

construction that has been measured only once as the variation in the

performance of the construction cannot be estimated. This could only

be determined by measuring a number of specimens of the same construct-

82 ion from which a better insight into the insulation properties could be derived. Unfortunately, due to various reasons which have been mentioned in the early part of this chapter, the limited numbers of timber walls and floors tested do not provide a full insight into the insulation properties of such constructions.

However, the range and means of measurements for the walls and floors tested are plotted in Figs. 41-43. Figs. 41-42 show the range of the airborne sound transmission loss of walls and floors respectively and they indicate that spread is severe at both high and low frequencies.

Fig. 43 shows a similar trend for the impact sound levels of the floors. A similar range of results also appears in the concrete floors measurements. (Ref. Appendix 6).

The standard deviations for all the tests have also been shown graphically in Fig. 46, and are tabulated as follows:-

Construction Standard deviation(s) Airborne Impact

Test 1-3 Timber partitions 1.92 dB - Timber floors 0.50 dB 0.50 dB from Appendix 6 . 5" concrete floors 1.12 dB 0.71 dB 6" concrete floors 0.85 dB 0.91 dB

However, the standard deviation of 0.5 dB for both airborne and impact sound insulation for the timber floors cannot be considered as accurate, as they are derived from only two floor measurements.

The Dutch Code (Ref. 74 & 103) has taken this condition into account.

The requirement is that the average results in the different frequency

83 bands should be decreased, in the case of airborne sound insulation,

or increased, in the case of impact sound insulation test, by the

standard deviation of the average before calculating the rating, and

if only one, two or three measurements of a certain construction are

available, the measuring results in the field should be decreased or

increased by 3.0, 2.1 and 1.7 dB respectively.

The range of the reverberation times in the receiving rooms is also

rather great (Fig. 44). Perhaps the spread could be minimised and

greater accuracy of measurement results could be obtained by placing

some absorbent materials in the rooms during the tests.

It is known that the sound insulation of a large number of nominally

identical constructions is not the same but exhibits a certain

variation. Therefore, it may be preferable to build a construction

with a small spread and standard deviation, but as yet too little

is known about these characteristics for various common constructions.

It is therefore important to investigate further the range and

standard deviations of the insulation occuring in practice for

various constructions.

6.54 Possible Means of Increasing the Insulation properties of these

Wall Types

The walls tested did not have infills in the cavities. It is

possible, with lightweight forms of construction, to improve the

airborne sound transmission loss by increasing the width of the

cavity and by providing full or partial absorbent infills in the

cavities, as shown by many research workers (Refs. 48, 79, 80 &

174). The mass of the skins may also be increased, but Mulholland

84 (Ref. 125) reported that when the skins have sound absorbing material

placed between them, the increase in insulation obtained by increasing

the mass of the skins is less than the "mass law". He also reported

that an increase of approximately 3dB per doubling of the separation

between the skins could be obtained provided the separation does not

exceed 150mm. Utley et al. (Ref. 174) reported that the size of the

coincidence dip could be reduced by increasing the damping of the

panel by "sticking damping material to the panel", while the addition

of an absorbent material in the cavity will be less successful. They

also discovered that only a small increase the transmission could be

obtained at low frequencies by adding absorbent material, largely

due to poor absorbing qualities at low frequencies of the absorbent

material added. But Mulholland (Ref. 125) who used various types

of inf ill materials, such as rockwool, polyurethane and polystyrene,

indicated that rockwool could in fact overcome the mass-spring-mass

resonance dip.

However, all these research workers, together with Ford et al.,

(Ref. 80) concluded that the overall difference between a full and

partially absorbent filled cavity is not significant, and in the

case of a partially filled cavity, the position of the absorbent

material is not important but there is still a considerable improve­

ment over the case of an empty cavity. An average of 7-10 dB

increase in transmission loss was found irrespective of where the

absorbent material was placed, while completely filling the cavity

resulted in a further increase of only 1-2 dB.

6.60 Comparison of Results - Classical and Simplified Methods of Sound Insulation Measurements

Tables 13-15 show that the A-level difference between the source

85 and receiving rooms taken at the one-third major diagonal distance

and corrected to 10 log^(S/A) at 1000 Hz, yields a simplified STC

reading which correlates very well with the results obtained by the

laborious classical method.

In addition, three other level-differences between the source and

receiving rooms were obtained (see Table 13-15). They are (dB - dB),

(dB - dB(A)) and (dB(A) - dB) are all corrected to 10 log^CS/A) at

1000 Hz. It can be seen that the (dB - dB(A)) level differences alone

(i.e. without correction) gives, in most cases, a result very close

to the field STC readings. This is because in all cases the dB

readings taken in source rooms are 3-5 dB higher than dB(A) readings

taken in the same room. (dB is always higher than dB(A)).

The A-level difference plus the correction appears to give closer

results.' This has also been shown by Brittain (Ref. 58). This

indicates that there is no reason why a pink noise source as proposed

by Siekman (Ref. 163) should be preferred as a white noise source

can give the results to the same accuracy that Siekman et al. claimed.

6.70 Conclusion

The advantage of the sixteen-frequency tests is that the sound insula­

tion of the construction can readily be plotted in a clear graphical

form. But, unless needed for research purposes, most of these

readings are not required in a normal building insulation performance

test, where only a final single-figure rating is required. Thus the

classical, laborious and uneconomical sixteen-frequency test

procedure should not be entertained in the field. A simplified, easy

86 to conduct, economical and sufficiently accurate method should be adopted. A correction table should also be used to avoid the necessity of a laboratory reverberation times analysis. In these particular measurements , a correction of

10 log(S/A) = 5 appeared to be appropriate to the A-level difference.

The ability of an STC rating to correlate well with the occupants' subjective responses is still dubious. A social survey (Ref. 82) in

NSW Housing Commission flats indicated that 50% of the occupants were satisfied with an STC 50 between flats. Undoubtedly, the percentage of satisfaction will be lower in middle and quiet localities if the same STC performance is encountered. A re-vist to the Test 1 site revealed that the STC 49 brick party wall did not provide adequate acoustical privacy between the two attached dwellings (see Fig. 34).

The occupants in both dwellings complained that, particularly at night when the background noise is quite low, movements and voices from neighbouring rooms could easily be heard "though we can’t hear clearly what they are but they are very annoying".

This is typical example of a Housing Commiccion medium density design where the acoustical performance of the party walls are severely degraded by flanking paths. Firstly, the building is designed as a detached dwelling where the problem of noise from a neighbouring building is non-existent. However, the design is later adopted for an attached or semi-detached lay-out but no acoustical problem is envisaged or considered. Fig. 34 shows that sound from room 1, in the absence of a wing wall, will by-pass the windows and be

87 transmitted to room 2 without much attenuation and vice versa.

There is also an urgent necessity of changing the impact test method.

The ISO tapping machine not only cannot simulate actual footsteps, but is very clumsy to use and time consuming. A simple and quick method like dropping a steel ball of known weight, falling from a constant height as a driving force, similar to that developed by the

Institute of Applied Physics, TNO-TH (Ref. 171) for measuring the mechanical impedances of building structures should be considered.

Impact sound level measurements can be readily made with a sound level meter and prediction and rating of the insulation properties of floors could be derived from these measurements.

88 Euilding B—1st.Floor Building A—1st. Floor • h M to H w o Q) H

/ — 00 d X X) 00

CM CM

r-H

<3- CO CM M3

Fig.34.Semi-detached brick-veneer dwelling — Sound Transmission Loss Test for Wall 1 and 2. eg O TEST 55 hJ 00 Q> l > JO u — o o 6 o 8

eg o o r co — <

eg cr> eg m eg

co co uo o co

O co co eg

m sr go oo 53 a. a Pi 0)

i hJ — cu > 0) i

rH r & < CO co 53 cr td — u id

m vo

eg eg o

m oo eg co

«H Pt, co 53 o o cr rH r — O * H 0) I

rH -I QJ > QJ

Fig.35. Brick-veneer dwelling — Sound Transmission Loss Test for Wall 1, 2, 3 and Floor 1 in Room 3 and Impact Insulation Class Test for Floor 1 in Room 3. Simplified Method of Evaluating STC Rating Using Measurements at 1/3 distance of major room diagonal from the Test Wall

ASTM RATING STC Specimen description refer to Fig. 38.

I

M

O O

*H -H t i-l H •H r-H O cj O C

O O O PQ N C TABLE 16 Stud vail airborne Sound Transmission Loss Test 1-3

( CaJcu l^ii'ovi Seg Appendix 2 & Appeod>x 3 ) ,

Test no. 1 2 3

Wall no. 1 1 2 3 1 2 3 X s

Frequency

50 20.57 13.94 12.92 18.25 19.75 18.20 14.44 16.86 2.80 63 15.54 11.45 10.84 15.65 14.54 17.50 18.41 14.85 2.62 80 11.34 9.75 12.84 13.65 13.94 15.87 15.50 13.27 2.02

100 16.77 12.94 16.54 19.04 14.19 8.15 15.11 14.68 3.21 125 17.08 12.54 17.84 15.25 16.79 12.45 19.68 15.95 2.48 160 20.37 16.61 17.39 18.41 16.79 15.84 20.68 18.01 1.78

200 26.08 20.58 23.79 21.50 22.46 15.72 21.66 21.68 2.99 250 23.79 24.24 21.36 23.37 27.99 20.59 24.45 23.68 2.27 315 24.28 27.29 24.85 26.05 26.21 21.97 28.12 25.54 1.88

400 30.94 28.91 26.22 29.80 30.92 25.97 30.02 28.97 1.91 500 32.53 30.21 28.32 32.29 31.81 28.43 32.29 30.84 1.71 630 34.09 34.77 29.55 34.29 34.30 29.34 33.56 32.84 2.22

800 34.84 35.70 33.37 35.51 34.47 28.13 34.42 33.78 2.37 1000 37.64 37.00 33.77 35.26 38.25 32.14 37.26 35.90 2.14 1250 37.29 37.77 35.77 36.99 39.00 35.34 40.21 37.48 1.62

1600 39.93 40.81 36.15 38.99 40.21 37.14 41.56 39.26 1.73 2000 41.55 41.22 38.32 38.02 41.92 38.73 39.72 39.93 1.39 2500 38.14 38.89 37.10 34.80 38.91 35.42 39.10 37.48 1.66

3150 32.37 31.58 30.55 26.26 32.88 29.59 32.67 30.84 2.21 4000 34.30 29.57 30.47 20.66 32.88 31.89 33.96 30.53 4.36 5000 40.70 33.46 30.77 17.26 31.88 31.86 32.66 31.23 6.45

STC-field 34 33 33 30 34 29 34 32.29 1-92 1

II N > OO OO STC - from average x - 32 CO

FHA Results: Laboratory results only - STC 39*

EBS Laboratory Test Result: STC 36***

* Based on similar type of constructions (Ref. 30, W-27) ** EBS wall lined with 5 mm hardboard both sides while all walls in Test 1-3 above are lined with 10 mm Gypsum plasterboards on both sides. TABLE 17 Floor-ceiling assemblis Airborne and Impact Sound Insulation Test 2 & 3

low Sec Afspetodr* £ s. Appeiocb’x 5 . Test Airbome-STL Impact-Ln Test No. 2 3 2 3

Floor No. 1 1 X s 1 1 X s Frequency

50 17.42 15.42 16.42 1.00 71.92 77.60 74.76 2.84 63 21.31 18.28 19.80 1.52 77.26 74.70 75.98 1.28 80 12.72 13.12 12.92 0.20 75.64 78.71 77.19 1.53

100 15.82 14.97 15.42 0.45 78.27 74.22 76.25 2.03 125 21.37 15.97 18.67 2.70 81.20 80.83 81.02 0.19 160 18.32 20.93 19.63 1.31 86.27 82.25 84.76 1.51

200 24.89 26.48 25.69 0.80 80.42 79.44 79.93 0.49 250 26.77 28.48 27.63 0.86 78.48 79.77 79.13 0.65 315 27.74 29.43 28.43 0.84 79.21 81.74 80.48 1.26

400 30.84 31.06 30.95 0.11 78.62 75.25 78.44 0.19 500 31.45 34.45 32.95 1.50 71.01 73.20 72.11 1.10 630 32.45 34.45 33.45 1.00 71.01 70.87 70.94 0.07

800 35.75 34.94 35.35 0.41 64.79 67.24 66.02 1.22 1000 37.86 37.26 37.56 0.30 60.09 59.61 59.85 0.24 1250 37.86 39.36 38.61 0.75 56.20 53.81 55.01 1.20

1600 39.05 38.84 38.95 0.11 51.53 49.03 50.28 1.25 2000 40.44 39.98 40.21 0.23 47.40 45.71 46.56 0.85 2500 37.99 38.90 38.45 0.46 46.63 44.50 45.57 1.07

3150 31.87 39.27 35.58 3.69 43.98 42.78 43.38 0.60 4000 34.29 38.63 36.46 2.17 37.15 39.47 38.31 1.16 5000 32.57 35.93 34.25 1.68 31.71 36.25 33.98 2.27

1 STC-field 35 36 35.50 0.50

IlC-field 37 38 37.50 0.50

STC - from x 34 s = 1.23 IIC - from x 36 s = 1.28

FHA Results*: Field STC 35 Field IIC 36

EBS NIL

* Based on similar construction (Ref. 30, F-31) 60

wa 11 1 STC 33 —O- -O- wall 2 STC 32 ■x*- vail 3 SIC 30 floor 1 --- II- -II- STC 35 50 Wall 1-3 : 75x45mm dressed hardwood stud walls both sides lined with 10mm thick Gypsum Plasterboards. Floor 1 : 20mm thick T*.G radiata pine flooring cn 175x 50mm hardwood joists with lOirta thick Gypsum plasterboard ceiling underneath.

40

30

20

10

0

1.6k 2.5k 4k Frequency Hz

Fig.38. Airborne Sound Insulation Test No. 2 N o rm alised T h ird O ctave Band Im pact Sound P re s s u reL ev el R e0 : .0 0 0 2dyne/cm ' 523 < •H •H XI -H — •u 4-J o e cd tn dB

40 80 90

50 — / X -X _ Fig. Floor Floor 4— \\ j 8

—

A V 0 SVj 40. ----- 1 1

100 \ y Test Test — L 'LL

/ jj — 1 __ in Impact 125 | f\/' a ■ -4 - 3 2

A -

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Test 160 : :

/ Gypsum 50mm 20mm ZOmra floor 175x50no floor -iunzn -20mm k x_ cel centres f

v Joorinr. 2C *

Sound ling

Nos. rNT x hardwood 0 thick thick

cnicK thick 1 1 250 __ plasterboard Test Test . ; hardwood :

zr

315 ISG T uypsum TSC LG 2 Insulation 3 2

loists and 400 hardwood radiata : : radiata \

joists \ IC IC \

piascerDoara 5C w

ceiling 3. \ i with Zx \

0 8 7

pine 630

pir.e/hardvood flooring with

10m

% \ Class 80 \S underneath. flooring \ \\ \ 1 0

thick Ono

V

or \ 7 ~ !

\ \\ thl 1.2

Test 17 on

5 ck r\ \

\ >t 5k 1.6k \

Frequency

\

1 — V v for \ \

2k s >

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Hz \

5k A v 1 \

> \ , V

\ \ 5k V \ \ ' ■80

Impact In su latio nClass — IIC 20 dB

X) c O CO X) 50 Class

4J CM a o CX3 O a, o 6 • 60 M O XJ ••

■H 70 rH tO

O

X) c o o QJ to C •H

100 160 1000 1600 2500 4000 Frequency Hz

Fig.44.Average RT in receiving rooms Test 1-3 dB

Sound Pressure Levels 120 ** *

Fig. Refer Refer 45.

bouring linear; room to SPL Comparison APPENDIX APPENDIX

A-weighting**

in and

receiving ---

construction

background

5 3 between

• --- Fig.

( •

room; A3.21. —

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Sound

noise* background site

—

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Fig.

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Levels ------z) background Frequency

levels

in

at

average receiving corrected

Hz noise neigh­

io46 s ta n d a r ddeviation a t at I te & t fV e q u eq nee> Ff£.

"Uvnbfcr Airborne 46 Airborne Impact

2:

60

construction

Sound 100 St^odord floor Sound Sound

125

- 160 Insu Insolation Insulation ceTUo^

200

as atlon

'I 250

xz shown .

3 v

Tests T is ^sserobUes a Tests Tests

'U one-third-octave 400 oos

500 tbr

In

for

tbr

timber Fl£s. 630 fbr

I

timber "Umber 600

3S "Urober

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39

1250 Test.

f

• floors frequency

1600

p

1

— .2500

3 Hz

. IS

dod

Plate 2 AMI-Jorgen-40W loudspeaker facing the comer of the room away from the test wall. Plate 3 e ®

B&K sound level meter type 2203 with octave band filter attachment and B&K type 4220 124 dB piston- phone on left.

Plate 4 Standard ISO tapping machine. Plate 5 Laboratory set-up of some equipments: a. B&K filter set (microphone amplifier type 2603 on top and band-pass filter set type 1612 underneath); b. B&K type 2305 level recorder; c. Nagra IV SJ tape recorder.

Plate 6 In-situ set-up of some equipments: a. Nagra IV SJ tape recorder ( record mg pisfcl slocks) •> b. Nagra III tape recorder( Source) ; c. B&K filter set (as above); d. B&K type 2305 level recorder. Plate 7 GR type 1921 real-time analyser with storage display unit on top and Facit punch tape machine on right. C use, ^ resuJ'Vs — Sc 'Tevbics A S. /t - AJ.^)

Plate 8 B&K type 2305 logarithmic level recorder. Plate 9 Nagra III mono tape recorder( 4or source)

Plate 10 Nagra IV SJ two-channel tape recorder{

f (l\)(L< VC vo 2S ^ . 7.00 CONCLUDING COMMENTS

7.10 Introduction

In building codes, the required sound insulation and isolation between

two rooms should be most specific. It is not sufficient to specify

only the STC or Ia of a wall or floor-ceiling assembly which provide

a sufficient sound transmission loss as measured in the laboratory,

but which may not ensure the required sound insulation and isolation

in an actual building. This single number STC or Ia rating, which

is generally accepted by architects, builders, engineers and building

tradesmen, should only be considered as a design guide and not the

eventual attainable isolation or insulation.

7.20 Sound Isolation and Insulation

Transmission loss alone is not a good indication of sound isolation,

as it does not account for flanking transmission which is very

difficult to calculate and control. It is the sound isolation and

not the insulation characteristics of the separating walls or floors

that control the occupants' satisfaction. Since the level of

occupant satisfaction with various values of sound transmission loss

is unknown, the effectiveness of using STC to gauge adequate privacy

and isolation between rooms remains dubious. Also, as indicated by

Clark (Ref. 64), STC is relevant chiefly for speech and music.

In the early sixties, Cavanaugh et al (Ref. 62) showed that speech

privacy depends on more than the transmission loss of the dividing

wall. It also depends on the background noise in the receiving room,

89 the sound absorption in the receiving room, the voice effort and the

amount of privacy required. Later, Young (Ref. 188) revised Cavanaugh's

et al. work by measuring the background noise level in dB(A) and using

the STC rating of partition and showed that his privacy index

correlated with subjective reaction better than did Cavanaugh's et al.

Recently, Schultz (Ref. 157) simplified both Cavanaugh's et al. and

Young's works by using the A-level difference and the dB(A) background

noise level. He showed that his results correlate even better with

subjective reactions than did Cavanaugh et al. and Young, for three

different sources spectra (Ref. 157). Schultz named his system as a

Privacy Index (Ip) and claimed for it the additional advantage that

no normalisation is required. (see Section 4.26 p. 52).

Beside Schultz, we have mentioned that Burgess and Harman (Ref. 61),

Stephens (Ref. 165) and Jackson et al. (Ref. 97) all agree that dB(A),

besides its simplicity, has some attractive advantages. (See Section

4.40 p. 57). It can be obtained readily from the sound level meter

with a standardised A-weighting network (based upon the 40 phon contour)

which discounts low and high frequencies in a crude simulation of

human ear response. However, an immediate problem will arise if

Schultz's method of Privacy Index is to be used, as the background

noise in the receiving room is subject to change. Another important

point is that, although in the same building, the background noise

of a room facing a street is not the same as in one facing the rear.

30 Recommendations

The building of houses for people is a very special business and must

be conducted by informed people. In acoustics, we are generally

90 concerned with satisfying people, and it is important that we should

bear this in mind (though there are some hard cores who are never

satisfied, whatever the situation is!). It is appropriate therefore

that the number of people satisfied, or a similar criterion, be used.

An effective building code is certainly required to help in attaining

occupants' satisfaction. Unfortunately, the N.S.W. Ordinance 70 not

only is insufficiently comprehensive but also overlooks this

"consumer" requirement. What actually matters, is that an adequate

overall acoustical privacy should be achieved between the various

rooms when the building is finished. Thus the architect needs

reliable guidelines for his choice of construction. For a building

code to be useful and effective in regulating the sound isolation in

dwellings, it is suggested that the following points should be included:

Field sound isolation should be specified in terms of A-

level differences and the STC rating used for only as a

design guide. The level difference (noise reduction)

should enable sound isolation between rooms not separated

by a complete common wall be tested, e.g. rooms separated

by a stairhall. (The standard test for sound transmission

loss requires a complete common wall.)

The maximum noise level in any room should be specified.

This is done in the Californian Administrative Code (Ref.

94) where the Interior "Community Noise Equivalent Level"

(CNEL) not exceeding 45 dB in any habitable room with all

doors and windows closed, is specified. Thus, residences

in locations with an outdoor CNEL greater than 45 dB, have

to ensure that the structure is designed to meet the

specified interior CNEL of 45 dB.

91 Compliance by design must be considered as essential, and must be clearly in evidence during project design stage.

Compliance to standards and requirements should be met prior to the issue of a building permit as correction for non-compliance after the building is completed could be very uneconomical.

A simple compliance test procedure should be used with minimum test equipment required, but results must be reliable enough to face legal challenge, if necessary.

An acceptance test, using a simple compliance test procedure, should be required to test construction sampled at random. Rooms tested could be unfurnished since introduced absorption can provide an additional reduction of the interior noise level by 4-8 dB (Ref. 94). If unfurnished rooms tested show adequate privacy, there is less tendency that complaints will arise when they are occupied.

The standard 16-frequency test should be required only if a complaint is filed alleging noncompliance, to pinpoint the fault that causes the inadequate isolation. The complainant should be liable for the costs of test unless the complaint is substantiated by the test, in which case the costs shall be borne by the owner or builder.

In deciding the types of sound isolation required, the background noise levels should be used.

Besides the control of plumbing noise, code should include provision for control of mechanical noise, e.g. lifts in multifamily flats.

92 - Serious consideration should be given to the effects of

floor resonance. Modern designs tend to use greater floor

spans and less concrete thickness and will tend to create

greater noise problems between upper and lower rooms.

As a result of such a Code, builders and architects would be encouraged

to adhere to more stringent quality control and inspection procedures

during construction and to include noise control details and

specifications in the project design drawings. However, to reduce a

sudden profound impact on the building industry immediately after

such Code goes into effect, it is suggested that Schultz's "stepwise

approach" (Ref. 156) should be adopted. Marginal allowance is wider

when the Code is just effected but gradually narrows, in steps, once

the construction industry has learned the "know-how" to improve

assembly techniques and to avoid flanking transmission. Then full,

strict compliance should be imposed for buildins to achieve the

required privacy.

7.40 Conclusion

The New South Wales Ordinance 70 provision for acoustical require­

ments, like many building Codes in other countries, allows too many

opportunities for uninformed architects, builders and engineers to

make grievous mistakes. What a purchaser buys is only the PROBABILITY*

of residential quiet; he takes his chance, makes his own judgement

* There is no market on which one can observe people making explicit contracts for so much residential quiet at a specified price. The acquisition of residential quiet is a by-product, if any, of the contractual arrangement of purchasing a real property.

93 and eventually pays his own penalty if he is unlucky. Thus, with the aid of a useful and effective building Code, it is hoped that better and quieter buildings will be produced. As the right for residential quiet is part of the fundamental human right, each person should get his due share of peace at home.

94 APPENDICES APPENDIX 1

London Method of Field Transmission Loss Measurements

London (Ref. 115) developed a method for field transmission loss measure­ ment specifically for the purpose of determining, in the field, the transmission loss of partition or floor constructions that would provide data comparable to data obtained in the laboratory.

The London method differs from the ASTM method in the placement of the pressure microphones on the receiving-room side. London, in his initial experiments, restricted the measurements in the receiving room to the panel face. The method also suggests taking the measurements at the panel face in the source room as well if a diffuse sound field is not present.

Generally, eight readings at 150mm intervals are obtained over the surface of the surface of the test specimen in an area of approximately 0.2 square meter at lower frequencies and four readings, at 300mm intervals, for the higher frequencies. The microphones should be located as close to the panel face as may be possible without touching.

To initiate the development of a method for field determination of transmission loss, London first analyzed the nature of the sound field in the receiving room to determine:

1) how the sound pressure levels varied with distance from the

surface of the test panel;

2) what variations occurred in (1) with varying amounts of

sound absorption in the receiving room.

The resulting data revealed that considerable differences in sound pressure levels existed at certain locations for a specific amount of sound

Al.l absorptive treatment. These experiments emphasize the difficulties that may be encountered in taking field measurements and obtaining reliable

data. Of course, if the sound field in the receiving room in the field were to be investigated thoroughly, the average sound pressure level could

be obtained. However, this is time consuming and may still prove to be

not feasible.

As a consequence of this comprehensive analysis of the variation of sound

pressure level in the receiving room as a function of distance from the

panel face and quantity of sound absorptive treatment, London derived

three equations to be used in the evaluation of the sound transmission loss

in the field:

TL = Ls - Lr + 10 log10 *5(1+2/ S/A) (Al)

when f = 128 Hz

TL = Ls - Lr + 10 log1Q (h + 2S/A) (A2)

when f = 192 to 2048 Hz

TL = Ls - Lr + 10 logxQ (3/8 + S/A) (A3)

when f = 4096 Hz

where TL = Transmission Loss in dB

Average sound pressure level in source room

Average sound pressure level at panel face in receiving room

S = Total area of sound transmission surface

A = Total absorption in receiving room, in same unit as S

f = Frequency in Hz

London indicated that his method is relatively insensitive to average room

sound absorption and virtually eliminates the difficulties encoutered in

measuring sound levels in a test room having non-uniform distribution of

sound energy.

Al.2 APPENDIX 2

Mean Deviation (x)* and Standard Deviation (s)

Mean Deviation (x)

~(xl + x2 + x3 Xn>

1 11 (A) i=l

Standard Deviation (s)

(x^x)2 + (x2-x)2 + (x3~x)2 + . (xn_x)2

(xi-x)2 (B)

-2 x (C)

** Ref. 17. pp 29-30 and 111-114.

A2.1 APPENDIX 3

Field Sound Insulation Measurements Test No. 1-3.

Table A3.1-A3.15 are measured and computed results;

Table A3.16-A3.22 are computor computed background noise levels

Fig. A3.17-A3.23 are computor plotted background noise levels.

A3.1 APPENDIX 3

TABLE A3.1. Test No. 2 Wall 1 when the compressor at nearby construction site is on

Frequency Sound Pressure Levels in Background Noise Receiving Room

P A* Lin. P1 P2 P3

50 70 72 76 72.7 13.30 43.50 63 76 79 77 77.3 12.05 38.25 80 78 85 86 83.0 34.75 57.25

100 77 82 79 79.3 29.15 48.25 125 80 85 78 81.0 32.40 48.50 160 85 81 86 84.0 33.60 47.00

200 83 82 81 82.0 26.35 37.25 250 75 77 77 76.3 27.15 35.75 315 72 70 69 70.3 26.90 33.50

400 74 75 76 75.0 28.70 33.50 500 78 77 78 77.7 34.55 37.75 630 72 73 73 72.7 41.35 43.25

800 71 71 71 71.0 37.20 38.00 1000 71 71 71 71.0 41.00 41.00 1250 68 69 69 68.7 44.60 44.00

1600 63 64 64 63.7 43.75 42.75 2000 59 58 58 58.3 37.20 36.00 2500 54 54 54 54.0 35.05 33.75

3150 52 52 52 52.0 31.70 30.50 4000 50 47 50 49.0 31.50 30.50 5000 55 42 44 47.0 31.00 30.50

* Corrected to A-weighting — see APPENDIX 5 Wall: 230 mm (50mm cavity) brick party wall with 15mm cement render both sides. * u P a (V ;>■» c a o p m )

1

cs CM o oo rH CM CM CM rH co CM H CM CO i CM rs CO in oa o\ m O — i

o vo O o oo H CM vD - CM cm CO CM • CM m co H CM oo vo co CM co — h I

vO vo r cm CM 0O CM sf CM co o MO CO O OA CM st oo O CO O CM sf m — I

CM st O CM O o CM 00 O CM oo O oo H CM co CO CO CO CO m in r-l o H

vD o CM 00 st M* CM CO oa co CO CO O OA co cm O rv CO N r-t VO m m co

St sf MD o o 00 CM oo vo rH sf (J> CO CO co in CM cm co CO oa co CO co H

st sr St sr St st O vo O o O o rs H r-l O OA sr m CM vo St St CM rs

OO co

sf oo co VO O rH co OA o co 00 CM co co CO OA cm m CO co co CO CO

sf OA sr co 00 CM rH co St co r-l m co co CO N CO OA r-l CM co CO OA CM m

st O 00 00 fs sj- st o CO oo CO 00 00 co m CM oa st cm is CO CO co rs

sf st sr

vo O oa CM st m O o CO 00 o CO OA oa co CM rs « co co m m — i

sf sf oo -t vo co o OA sf sf o O CM cm rs CO CM o o co oa oo m rs m

sf Sf sf vo 00 o CM CM st st Sf sf O CM r-H sf cm co CM m OA 00 CO CO

o sf st sf Sf sf Sf vO o O sf sr CO vO 00 CM st m co co r m OA OA IS — I CM

st st vo Sf Sf CM CM rH vO O vO vo Sf vo sr in OA CM -I m rs in

st vo rs st Sf vO rH o o rs m Sf oo Sf st is oo oa r-H m rs O is OA m CO

st

Sf st st CM o st co Sf sf rs CM rs CM vo o o vo 00 oo vo in in CM

is st st sf vo st st CM o o st st sf St CN sf VO O oo vo rs OA m m rs

3150 51 50 48 47 46 48.4 1.2 3.43 3.9 52.3 4000 51 49 49 51 49 49.8 1.0 4.11 3.1 52.9 5000 53 51 48 49 53 50.8 1.0 4.11 3.1 53.9 Wall: 75x50mm H.W. timber stud wall with 10mm Gypsum plasterboard lined on both sides. IQ •K Q Q H < CJ P Q Q Q n a) cr a) d o >v d h Nf cm CO m rH

CM CM CM CO rH IN IN rH vO H VO CO

vo Nt 00 rH rH rH CT> H vO o r^. CM O ^ Nf CM cn CO cr\ H CO in m m

vO I m . CT\ — Nt oo o o O H Ov m Ov CO in O CM co H ■ 0> — co — I I i

M 00 rH IN cm rH in vo CO rH o o CM rH co in rH oo vO in CO H \D O O in IN I

-

CM O rH rH oo VO CO cr* rH CO to ov rH vo O Nt 00 H I o in rN m OO n rH m cm

CM CM CM ro Nt CM h O in CM O CO oo vO CO in O O N N CO O n rH vo o I

H co CM CM CM CM CM 00 CM Nt m O CM O in CO 00 O CM OV O 00 CS VO 00 o o CM

Nt

rH Nt CM CM CM rH CM O o CM CM CM rH Nt co IN O CM co Ov CM CO IN CT> m o CM

rH oo rH CM oo CO CM CM CM CM o rH IN. CM Nt CO CM O 00 m CM 00 CO 00 CM Nt CM 00

Nt O o CM CM CM 00 CM CM CM O vO Ov rN CM O CM m Oi

CM Nt vO Nt O CM 00 CO O CM O' CM VO CM vo CM CM h m o |N 00 co co M m co •

vo O M0 o o CM Oi vr co CO CO O CO CM IN oo CM O CM r-l ov O m ctv co O cn •

CO O oo o o CO CO O CM vO rH in CM 0 CM CT\ CM OV Cf> CM CM

CO CO o o o CO CO CO rH Nf CM I CO CO CO CM CO CM CT\ CM Nt in CM co in VO n

Nt CO CM o CO CO CO r CM CM CM VO OV m CO CO CO O CO Ov O Ov m to r-. CM cn — l

vo o Nt rH o co in CO IN CO I CM 00 CO CO CM CM CM h <1- co I vo in m CO CTi ov co n n .

CM o o o co co CO OV CO 00 CO O CO ov CM co CM cm m Nt CO in O Nf < in m m m — I

CM o o m co CO VO CO VO CM 00 CO vO Nt CM o CM m ov m m CO CM CO ov CO

rH vo CO O co rH o Nt moo CO O CO O CM vO CO CM Nt CM r-l OV CM CM ON CO co co in in

rH m CO CO Nt o o CO rH CO CM Nt Nt CM 00 CO CO r-l VO co m CM N o Nf CO co o

Nt

r-( m Nf O Nt m o o o O Nt CO O O CO 00 co

■K u il 10 log (S/A). Table A3.4 Sound Transmission Loss for wall 1 Test 2 STC 33 i x> CO co i I & H <5 — — — cn Ctf Ctl

o I P Q — 60 o M 0) cn 01 a 3 0 h I cm

co CM io o st o m r o n mi in O r-H 00 m in cr> —

-

io vo

r io — o CM cm o m mi o m co o O m mi m m l I

- -

r in — oo o o r vO o o mi co m io m o m m m — 4 I - l

o o N o mi H O vO CM io mi in in o CM CM <3- cn - -

o CM H O 00 CM cn io mi in m o CM m m Mf CM -

N 00 o vo o CM co in vo o (Ti >- vO io • — h 1

o n CM r-H CM H h o o CM CM H on cm oo oo CM O' oo in

Mf Mt CM CM i CM CM ^ o n o in cm m cm

h CO CM 00 cn n r-H ^ ID CM CM C' co cn cm m o> CM CM ov m

CM Mf mi O O VO CM CM CM O mioo m <1- CM CO co i CM CO o> t — —

- i < cm

CM mt O O CM Ml- in CM rM O in CM r O cm in CO i — —

4 l

vo

CM cn m O CO r-1 CM o co co o CTi CM r^- sf rH CO n C m

00 o o H co o CO H CO co O 00 m o o 00 cm CO n f-'. O

o o o CM CM co cm CO CO O 00 co CM OO m o o n cm CO o O

CM co co CO CO in o CO co co co O mt N rM CTi cm CO n r^.

H in vo o o vo CO im CO co io mi co CO io Mf CM Mf CM o CM in O 00 -

o o in im CM o co CO oo CO O Mt co n CM h OO cm CM Ml- in H CM CM

CM o vo m in o co CO co in in CO CO co cn co CM in CM in CO 00 00 O m

3150 29 29 28 28.4 1.1 2.97 2.88 31.58 4000 26 30 26 27.3 1.0 3.27 2.46 29.57 5000 30 33 30 31.0 1.0 3.27 2.46 33.46 Table A3.5 Sound Transmission Loss for wall 2 Test 2 STC 33 r i co rO i <1 H — — CO cO CO ctf — (D t I )

o rH P bQ o M cr a o p m CO <1-0 Oc CM CO o cm Cn rH Mt Mt Oc O VO CM Csl CM m O •

o 0\ Mt <* OO CM o cO H rH vO o OO vo rH v cm CO O I

•

M o CO vO ~d- Mt 00 o G\ Mt 0 r rH (N 00 oo o CM O — I • I

o ^ H Mt ■

vt mi rH 1^ ac O o vO cn o vO 00 CM CM CM O rH n o m I -

OO CTi VO H rH CO rv CO o CO Oc rH r". OC o m CO o

rH CM r o O oc vo on CM CM co O m O CM CO r^. CM O o oo CM in m —

H CM co 00 CM o

o o H 00 m oo CM CM CM rH Mt CM m rH CM co in H co CM co m

CM m sf mi O co cm VO cm cm O o CM co CM CM m CM CM CO uo'd- co -

vo r-'. oo CM Oc vo CM oc cm Oc CO m m o CM vO CM m CM m m CO

co o 00 o CM CM OV cm oo CM co co cn O cn CO O cn CM o

cm

*d- n oo CM o r^- co r". O o O CM oo CO O co rH cn rv CM o co

'd- rs oo CM o r^. co m rs r-. CM O - CO rH CO co > CM o m CO co h h

h in CO 00 vO CM cn in co rH vO o o CM co co co co CM co cn CM co

cn cm Mt

2500 34 34 34 34.0 1.6 3.53 3.10 37.10 Table A3.6 Sound Transmission Loss for wall 3 Test 2 STC 30 CO co tH I it

o Q <5 Q 1 Pd CO — M 60 cu cr QJ e r*N s CJ o CM h I

00 CM t cm 00 O Ml" O (O o r-N CM m — m rH o oo m CM m I I

n

CM CM H m no CO NO N Mf CM CO o in H o vO m in m I

Mf H oo H oo O CM Ml Nj- IN o CM m * o VO m co m — I I

rH O o O H CO in ON oo CO CO no vo H o OHO io < CM cr. o I 1

"

m rH H vO so CM rH ON CO Ml- cm m o m O m cm m in I

mj vO rH o rH ON CM H 00 o CO o n in O h M mi oo i — - - i

H CM o o CM h CM cm r-N CM O O O ON Mf cm H CM H OMn m h o in •

cm mi o CM cm CM H l-N. CM H m O H H CO CO CM CM n co co Mn • -

co h CM CM CM o on m m m CM CO CO H CO O io CM CM CM o •

mi o o MvOO 00 CM 00 CM CM CM NO 00 CM IN in O CM O CO CO H on 00 -

m

o o CM 00 CO H CM CM CM 00 CO vO CO CM ON CO O CO cm CTi CM n

vo co o CO CO CM CM ON CO NO CM CO CM ON o co CO O

oo CM o o CO O CO CO CM M r CO H o 00 O NO H in co m m H — H f

o H CO o o co CO H CO rH H IN CM H Mf CO o CM VO co cm VO m

CM CO m o CO CO CO CO CO NO CM CO CO o CO CM O CO ON co vo CTi ui n

H vo o o CO in m CO co CO OlOh CM CO cm m >n co ctn CT CO 00 m Oi n

CM o o o CO co M* CO mo co co CM Ml- n CO co CM CO 00 o cm

? CM o o on in CM CO o CM OO co CO h — in co O Si- oo CO o i

3150 20 32 21 24.3 1.0 3.71 1.96 26.26 4000 13 29 14 18.7 1.0 3.71 1.96 20.66 5000 8 28 10 15.3 1.0 3.71 1.96 17.26 Table A3.7 Sound Transmission Loss for wall 1 Test cn cn cn rH rH O i < & H — cd co cd cd

03 IS. CM H CM O cn vo kj in o m o m 03 in o rn m rs i -

•

fK. 03 H kj oo < M n m <3- vo o vo in o cm

-

co

rH CM — CM in oo oo • vo Ki o o m m o cm cn cti — I I ­

VO Kt H o o 03 cn cm is o oo o Kf - — — H i

N H kt CM vO cn oo O Kt m cn m o o O'! H vo rs W n

vo kj rH vO oo CM vo o m cn o oo o ON Kt H O'! rs O! -

CM Kf H cm o o CM H CM o o o cn CM n VO CM CN| <3- m cm Kt VO

cm M*

VO H CM CM O kt cn rH CM oo CM CM h s vo m H CM CM >-H m in m

•si 00 m o CM vo CM is CM CM o CM 03 vo rH cm CM co O in 0> CM in

vo

oo kt oo cm •vf o o cn h cn o cm O! rs CM ov fs» f"» cn rs is

o CM CO o o cn cn cn cn cn o r-s m CM cn cm cn cn co O! m m

m co CM cn, cn cn

o sf vj H vo o o vo CM kt H O CM cn cn vo cn cn m rs r m m —

I

h 00 CM sf o o o cn oo CM sMn H cn rs cn oo cn is rs. cm CM O'! CM m

sf cn CM o o cn CM H oo m m cn m cn m o

3150 30 29 31 30.0 1.1 2.97 2.88 32.88 4000 30 29 31 30.0 1.1 2.97 2.88 32.88 5000 29 29 29 29.0 1.1 2.97 2.88 31.88 CM 4-1 CO CM i i ON CO E-t H O hJ — — •u M cn W O > cd o OJ Cfl I I

Wall: as Table A3.3 o U-i rH U D Ci o 00 0) cr U O 1 CO o lO m H VO ON O o CO O H H n o 00 oo cm o O l

vo H ON 00 vO H CM co o o co CO CO m CO 00 O fN m o l

H -3 oo o H t csl CO VO co o o N ON co o r-H CO m — I I

VO cm t 00 vO o n 1^-0 O 00 O -3-3-00 o m m oo . m

— 1-3-00

-3 OO vO CM 00 cm CM 0 O O cm m m m n

CM H co m 3 O o CO 0-3-00 vO ON -3- CM moo H UN CM r- cm

CM N «

OO -3 N CO r-H CM r- n 00 m O CO CO ON CM H on r-

-3 N -3 CO CO OO CM n O o CM cm CM cm CM cm CM H CM CO ON r- ON o

3 -3- -3 -3- -3- CM -3 CO vO CM oo m O o CM CM co CM o CM O co CO n

3 vo 3 -3 -3 - on co o CM n CM CM CM CM CO CO O VO CM CO m r- H 3 "

oo -3 -3 -3 oo o o CM CM CM CM CO vo -3 -3 cm CO CO CM O co CO r — I

-3 r- CM -3 -3 o o o CM r^- CM OO CM r CM co — m OO co cm ! CM — — c I

o CO O • -3 m -3 cm CO o CO r CO O O CM O co m CO co m CO — — < I

H o vo CM CM 00 -3 o CO CO CO CO CO CM CM CM co r m CO r- —H 2000 34 35 34 34.3 2.0 3.46 4.43 38.73 2500 32 31 32 31.7 1.7 4.07 3.73 35.43 Table A3.9 Sound Transmission Loss for wall 3 Test 3 STC 34 i i i CO H <3 — — — cd cd co td

P v-/ o I co <3 —

vo h vj- CO CO on CM o o in CO O - st- H oo — 3- •

lo

oo o sT m CM * o N — O m m o — — l I i

O o 00 H r o ^ CO m o O <3- h f-H H H m — I

CM 00 CM o m r crv * N r->. -d- o OO vO O VO O oo H CO on — — n I •

vO o H 00 CM o CN H Oi sr 'd- o OO vO O ON oo CM oo o lO

o CM o H CM O o H CM CJV O co H • vo ON CM VO h vo — i

<

CM o CM m H CM CM CM cm CM CM co CM o cr>

Vf C0 h m CM CM CM m CM uo \f CM vo cm in CO oo CM H cm

m O O CM vO CM r^. CM vO CM VO CO CM M CN co C" CM CM m co o O -

O O CM m S r-l I CM co CM CM 00 CM oh co io co ON 00 CO CM cm 0\

■

vo

CO O CM N CO O CO • CM ON CO n CM OO vO CM lO CO CO m — *

00 o O CM ■ ON co cm co co o » m co n CM M M CO CM h — i

O o O CM m CO co

CM m O CO vo co m co vo co r"' vo

H vo o o U3 OO CO CO CO CO rH co MT CO IN co n cm vO sf H vO m

ON

CM o M o o CO CO N CO IN vo m CO o CO Mn CM O m r~'« co CM n

CM m o o co NO CO NO CO VO vO co o oo co CO O h CO > ON O — i

3150 31 30 30 30.3 1.1 3.37 2.37 32.67 4000 32 31 33 32.0 1.0 3.71 1.96 33.96 5000 30 30 32 30.7 1.0 3.71 1.96 32.66 Table A3.10 Sound Transmission Loss for floor 1 Test 2 STC 35 ^ o P«4 i rH ,0 t 44 4-4 P4 •H «H T3 *H O -O •H 1 •H H <-3 •H — 4-1 H 4-1 4-1 — • O O G >4 o G 60 g CO CO <0 S O O G CO O | G g o U o G G U G G G G G

• 1 1

O t m H c-. m O TO i rO rs •!-> *H O T3 r -H tG *H 4-4 — 4-1 — — O CO G G 6 g CO G B g O, CO 1 cd W G 60 X o Cu

IQ •- V-/ i o H <1 i t*4 Q Q Q 03 cG C — — G G O 60 O G Po G cr G 4 p CM co 1 H 3- CM o o o CO m r>. m i m m CO m — a a a a a a a a a a a 4 MCM CM CM vO 'd' CM CM CO CM m m CO r^. CO m m m a CM 00 O O CM OS CO OO CM 00 O CM m m r^- CO in CO m a a a a a H o i o o o CO CO o o CM CO r^. vO OO VO OCO CO CO o o CO CM m co r^> — H a a a p O CM O O CO m CO CO p o OCO CO O CO CM co r>. m vO r- 00 vO CM H H a a a a a p vO O CM CO CM CO i 1 vO c- CO Os co CM i CO m CO o m m — — — H 4 a a a a a 4 4 2000 33 33 34 33.3 2.0 3.74 7.14 40.44 2500 31 32 31 31.3 1.8 4.16 6.69 37.99 Floor: Floor-ceiling assembly constructed of 20mm T&G hardwood flooring on 50x175mm H.W.joists and 10mm. Gypsum plasterboard ceiling. o r CO < f^i o bO a — M cr a; a) to u P I vj -4 O io n o H i 4 in CM O IT| M Csl LO — l

(M

co ai cri m rs o ON MO vo CM OO no l 00 00 O

oo • — <4 o H oo cm o o r-'. »- CM h CO H CM I l

vD vO O O CM 00 H O rH CO cn OC 00 cO CO r^. OC r'- •

CM CM CM CO CM m CO O CTi ON 00 CO cD H Oi f''' •

CO CO O 0O ON — cD *4 i o CM [N (Ji CO CM ON co co — • 4 I

H >4 CM CM 00 CM O CO 00 -4 O O O CM (O CO cO lO tO i-H CM CO 00

-4- CO -4 CM CM CM CM » 00 CM 0O lO O CM O CM lO CM CO tO LO 00 — f

sT CM CM cO %4 ~4 H CM CM O CM CO o lO CM OC CO to to fs CO CM CO

M M" O CM lO CM CO cO CM CM CM CM CO MD O CO CO CM to CO H O H

cO CM cD CO 00 O O CM N N CM CM CM CO N to CO iO LO

cO CO O CM OO CM N CM CM cO OO co lO CM CO CO I co ^ -

•

00 cO M N M o O CM CM 00 CM CO O CO

H CM 00 CTc r- CM CM in CO cm cO

CM sf CM CM O CM CM CM CO m CO CO CO CO CM O CM - co OC CO co >0 h

vo O sT » O CM M- M n CO CO H CO CM CM CO Ml- CO H f'- o H 0O CO — I

OO CM -4 vo lO o O O -4 M CM oc CO CO CO CO CO H CO CO co oo oc CTi 00

CM O CO oo m O O CO CO CO O OC r-l Oc CO fO CO CO CO H m m oc O m

3150 34 34 34 34.0 1.3 6.83 5.27 39.27 4000 34 33 34 33.7 1.2 7.39 4.93 38.63 5000 31 31 31 31.0 1.2 7.39 4.93 35.93 Table A3.12 Impact Sound Pressure Levels in receiving room for floor 1 Test 2 IIC 37 cn i 1 rO < H P — — U cti w

o *-l r P* < CO H (U c o >N — o 00 M Q) cr p h CM I

vO st vo in VO VO o VO IN o in n CN vo o -t o Ov cn IN cn cn oo rs m on vO m n- ov n vo vO (N on

IN vo vO

vo

vO

vO fN fN VO vO vo ov n oo o n H in vo in cn in ov r-t VO oo o Sf sf oo cn in on cn n n. o vo .

IN. cn CN cn st cn n o o rN in in fN. in in fN m in 1- vo o oo m cn m OV in o CN cn n cn in CN in n

00 o o% st IN rN IN OO oo n in oo OO CN in rN m fN in in m in in cn o o o cn cn h o oo o vo in CN o

cn

co

o

st N cn m o rN vo m |N |N IN 00 vo IN o fN 00 IN IN 00 fN vo vO oo IN fN VO ^ co cn o sf cn in co 00

IN

h N cn in oo rN ON fN oo fN fN VO fN Sf in |N |N fN oo fN O |N fN oo o n rN rN oo cn m rN CN H n -

n vt 0O 00 cn CO VO N- o r-t IN ON IN VO IN in IN IN IN vO CO 00 fN o CN o IN rN ON CN cn IN IN n cn vO CN

N- n h vo fN CN IN |N CN VO IN |N VO vo CN vo cn o ON H ON ON |N rH |N O 00 ON cn cn CN m 00 00 vo O r — I

vo vo oo o vo vo vo vo vo Sf vo vo o vo cn Sf vo ^ CN cn cn (N nt m m m st vo vO IN in oo 00 rN m on ON

vo vo ON vo vo rH o o o in on o t o o oo vo vo CN cn sT - m m o on cn o vO IN 00 ON m m m o ON — 4 i -

sf VO sf CN o m m in m oo CN -ci- m m in m m VO rN cn cn o vo ON m m m m m in m 00 ON m i cn o — i

St st S vo sf in sf < O O on m IN sf sf m m cn in m cn cn CN CM CN cn vO m m h cn in ON st vO cn m — 3 I - I

sr

sf st CN st - sf 00 st st sf o O O n on ON in sf st sf vo CN o sf m rN oo vo IN in CN sr CN fN n o 4 -

sf VO sf

vo sf sf st st st st sf CN m O O h CN cn 00 oo O sf sf oo m in vo sf --H t st in m cn 00 r-1 H cn — i

3150 36 37 39 44 45 45 40 41 42 41.00 1.5 4.99 3.02 37.98 4000 31 30 33 37 39 40 34 34 36 34.89 1.4 5.34 2.74 32.15 5000 26 28 27 31 32 31 29 29 29 29.11 1.3 5.75 2.40 26.71 T a b le A 3.14 Im p a c tSound P r e s s u L r e e v e lsi n r e c e i v i nroom g f o rf l o o 1 r T e s t3 IIC 38 CO it iH C i H P — >H CO a) O o h I I o 1 H < < CO hJ H -1 ►J h t-3 r-I .-I ►J ►J — pH 60 o Po cr u (U G a cu 3 3 st I CM vO rs oo a\ CO m C H vo St vo st mo o NCM st st rs vo IS is rs — O rH m MON CM cm OO vo vO co rs is co rs cr\ m O co CO I

too

vo vo oo vo st vo vo |S IS o H vo o is rs rs CM 00 vo m O cr> rs CO is O is O rs is co I

oo vO rs n rs CM st rs r-I CM o st o rs in > rs is CM cm is rs CM m N st CM CT\ co is — cm co — I I i

st vo rs CO vo vo 00 rs o o is O rs o vo is vo rs st vo av ov m o av 00 vO vO ifl m OV o O o\ cm

St CO oo Ov co rs is vo is st CO H is is cm rs Ov o cr» 00 vO o vO N co CM co m is m in rs m O in m

(Tl cm oo is 00 o is is is oo vD ^ N vo o oo — oo rs oo rs 00 oo rs rs m cm CO CTv — N n m is CO i • l

00 CM O o is rs rs 00 is vo rs vo rs O rs IS rs oo o m vo is is rs O st CM vO M st m m m rs ... -

vo is rs co CO St CM vo sf CM o rs co co o is rs rs oo 00 rs rs rs m m rs rs m a\ is O co in m

is co rs VO M co rH av oo o co o oo o — 00 is OV rs oo cr» m cm CM oo vO m — is oo m CM CM is is i I

oo N st O o rs rs IS is vo rs vO rs Ov IS vO IS rs O o CM — St CM CM is IS rs IS IS rs co cm in rs co in I

CO IS cm co CM 00 st m O o is co rs co cm rs — is MO CM IS co co CO vO * io cm is CO is H |S co co oo o — t I

st vo is o CM vo |S o o o CM co CO 00 vo co co o is rs r-H oo is O rs O ov IS o o M3 * co rs |S m — i

.

vo vO St o o vo |S vo vo vo vO vo vo VO vo vO CM St oo rs oo vo IS vo vO vo vO m co is o st CO cm vo CM CM

vO o o o vo vo in 00 CM in co in av o m OO in Ov o is m m CM cr» CO m is m 00 co Ctv m st VO t in m -- l

vO m CM CM rH st o CM CM m cm cm CO cm m m m co m co m m CO m CO m CM CM in CO m I m 00 00 m T

“ H

vOCOH st st st St St st St — vo o IS oo oo st oo vo "3- o IS 00 st sj N CM o st st oo oo m CO st st OMn m co OHO I

st St St St st St CM o o St St st st st St St o in CO st st rs oo rH oo st co CO cr> co o St CO o

St 'tf CM o CM St st st CM St st st H rs oo in o co co CM o St o st rH ct> — CM co m in cm oo co cr\ I

3150 40 40 40 39 40 40 38 38 40 39.44 1 .3 6 .83 1.66 37.78 4000 36 36 36 36 38 37 34 33 36 35.78 1 .2 7.39 1.31 34.47 5000 33 33 33 33 34 33 31 31 32 32.56 1 .2 7.39 1.31 31.25 Table A3.15 Reverberation Times in Receiving Rooms Test m » r rH CO •H — cd o o — a CU 04 a c a) 1 1 rH 04 CO CM CO H •U cn OJ o • & Pd •H ■U > a) u cd O oj

rH O 04 CO MO O' 00 H * m rH ON h B aj P 04 a CT cl a 3 m ) 1 M3 o mo O r-t o 00 o cr> o o o MO m m in o o MO o in m o O' • • • • • • • • • • •

mo 04 O 00 CO o o o o o mo m o o o o o o mo o m MO o 0> o o o O' o 00 • • • • • • • • • • • • • 00 o rH MO o O MO o m o MO o o o O' in ON m o m o 00 • • • • • • • • • • • rH o o 00 o o 00 MO o OM0 MO o 00 o o o MO 00 o 00 O' o O CTO CT' O O' • • • • • • • • • • • • • • • • • rH CM M0 O O' m o 03 00 00 o o m 00 00 o CT. o o O' • • • • • • • rH MO rH o o o 00 CM o O' 00 o *H rH 00 O' rH CM rH CM o 03 • • • • • • • • o CM *H cn o o rH rH o rH o 03 rH 00 rH o CT> O o rH rH m MO H rH • • • • • • • • • • • • • CM rH m o rH CM rH rH CM H rH 'd- m o rH rH rH H*H rH CO Hr rH rH rH rH rH CM MO MO HrH rH CO • • • • • • • • • • • • rH CO rH 00 •H CM CO rH rH 00 'cr CM CM M0 rH rH O' O' m • • • • • • • • "d- o CM H 'd- HrH rH HrH rH O o rH "d- rH rH m CO m 00 O CM in CM rH HrH rH O' • • • • • • • • • • • • 'd- m O O CM rH M0 rH MO oo rH M0 rH MO CM o MO CM CM CO CO CO 03 • • • • • • • • • MO rH rH co O CM MO rH rH 00 rH rH rH M0 00 rH CM O' CM 03 OCO CO MCM CM MC CM CM CM rH • • • • • • • • • • • • • • 00 O O o> rH CM rH rH rH rH rH 00 rH O' MCM CM rH 03 CM o 00 CM o m O • • • • • • • • • • • • rH o O O rH CM o. 03 rH rH rH 03 o- 00 o -MO o- CM rH O- CM MCM CM CM CM o • • • • • • • • CM O O MO rH MCM CM rH CM m 03 O' rH 00 CM rH o CO 00 CM CM rH CM o • • • • • • • • • • • • rH MO -d- rH O MO MO CM 03 rH rH rH MO rH CM rH 03 r-' CM rH rH CM O 03 • • • • • • • • • • CM O O rH rH CM O CO o. rH rH CM rH m OO rH in o CM 00 m MO m o rH • • • • • • • • • • • • • • • rH rH rH rH rH CO O' CO rH rH 00 rH CM MO CM m o O o >d- m rH CO m • • • • • • • • • • rH rH *H rH CO o MO CM rH rH rH rH rH <1- rH m rH CM rH o m CO rH CO • • • • • • • • • • • • • • 'd- rH rH rH o rH o o m o o rH rH rH rH rH o rH o o HrH rH o 'd CM rH rH CM • • • • • • • - rH o o o rH rH rH rH rH rH CO m m rH o rH rH CO o rH CM CM rH • • • • • • • •

average reverberation time. Mean of T 1.3 seconds. TABLE A3.16. id I b dhOHdAM WILL rdINi A ddAFH P Oh LINJFAH A\)I) A WF.I driTFD bH J\)]) LE'OFLb FhOty PAPVH l'APF Wil'd DATA CdANNFLS 13 TO A3

IN i P'GnA i I 0 W xIFjF? i * SECONDS.

DKbChid’i i ON? SOUND I NSiJLA i 1 ON I Fbl Wn. l. FACC d0 (. JM D N 0 I b v bx^ C T F' IF . bOfJHCF hOOM 1 .

LOAD TAdF AND SFT TO SIAhT

: 1 3 • V.’ 0 r: Fv.* • *.• L1 — i 3 • o v.< = 0 • V_' = F0 • 00 : l a : 0 S v • so s S 'J . S 3 - 14*0 0 = o • V.1 0 = S • so- : l s : 0 S a . SO = SA • S 0 = 1 S • v.' v.' — 0 • V.’ t-' = S A • so : l : 0 3 3 • 7 S =. 3 3 . 7S- 1 f- • v_- 0 = 40 . V.' V. = — 0 • 3 S : l 7 : 0 a 0 • 0 Av.- • 00 - 1 7 • 0 0 - 0 • V.' 0 = • 3 0 • : 13 : Oaf • so r. AF • S 0 = 1 3 • 0 v.- = 0 » L' L' = 1 f • 30 : l -> : 0 3 7 . so - 37 • S 0 = 1 7.00 = V.- . 0 0 = 1 S • 0 0 : FO : 0 A /i • so =. A A . Sf - F v.1 • v.' c — 1 00 • O V.' = FS • A0 : F l : 0 a 7 • 00 - A 7 • V.' v.' = FI 1 FS • 00 = 3c' • j^ : FF : 0 A 7 . FS = A 7 .FS = F F • o v.1 — 1 (' • V. ^ — 3 3 • 3 ^ : F 3 : 0 a 7 . V S — A 7 • = F3 .00 = F0 0 • V.' V.' = 3< . 3 S : fa : 0 a 7 • o o - A 7 • 0 ^ — F 4 .00 = FS0 . 0 L = 3 3 . A0 : ^ l>. : 0 a , . so - A > . ^ - r.b . Ov.- = 3 i s • V.* V.' = /IF . J K. : : r : 0 a < . 7 s = A.) . 7 S = ;.D . 00 = xi 00 • V. 0 = A 3 . 1 s : r 7 : 0 a . * . C. - A.} • F 3 = F' 7 .00 = S v c* . 0 V.' = AS 0 s : 'r 3 . /, < . s 0 n /i . Sv.= Fo .00 = <- 30 .00 = L.C . f 0 J ‘ * : 0- /j 7 . •- s. - A 7 . F A — F 7 . 0 V = >3 v.' 0 . v.‘ v_' = / f • /, s : : { n r . FS — A X . F S - • ? * v. v. ■ — 1 .o = nr • F.S : 3 l : 0 ax • t. v • = XI x .00 = 3 1 .00’ = 1 F . 0 0 = /: r • r 0 J 7 \- : 0 a c • S ^ - /i F. . S c — O F • v.’ v.' — 1 x * V.- L' — A3 . SO ; 7 F ! v. ■ A '■ ‘' S n Ao . r: s = 3 3 • 0 0 = F . 0 0 = /i i i.\ s : 3 /i : 0 s 7 . FS

- 37 • FS = 3 A . 0 0 = F A • 00 = 33 . s s : 3 s : 0 7 r • V V = 3 r • V.' ».■ = 3 3.0 0 = 3f . 0 0 = 37 • F l : 3 r : 0 3 3 . 7S 3 3 . 7 S = A(' » v. ^- = a • 00 = 3 A • 7 S : 7 7 ; O ' -* . F S -■ A 7 . F S = 3 7 • v.- 0 = s • 0 0 = FV • 7 S : .3 3 t 0 F x1! • 0 V. = A A ♦ 0 0 = 33 • v.’ v.' = f A • 00 = F 3 • 70 : 3 v I 0 f 0 . FS - fO . FS = 3 v . 0 0 = 3 • 0 0 = 1 7 • l S : /1,0 : 0 FO • 00

- F v. • 0 — A v.’ • v.’ v.< — 1 0 • 0 0 = 1 7 • SO : a l ! Ft.- • V. v. z. fo • V.' 0 = A i • i_* v.' — 1 F • 0 0 = i S • 7 0 : /i F I 0 F 0 • 0 0 =. FO • V.' v.' = A F • v.* v.' — 1 r • 00- 1 3 • AO : A3 I 0 F v . 0 0 n F^- . 0 0 - A 3 . 0 0 = f0 • V.' = 10 • 7 0 /•KiUxiM Ihx-K dEADF-d 10 STOr

r

Key- Column 1 -linear

Column 2 -channel

Column 3 -frequency

Column 4 -A-weighted levels

Column 5 -linear Fig. A3.17 Sound Insulation Test No. 1. Background Noise Spectrum. Source Room 1. 16 Sec. Integration Time.

b 0 1MD rr.FSBURF LFVPL DP - hC - 30 - 40 - SC - CC - 70 - 30 le!34S673* lt:34S^73* 12343^73* !P34Sf73* 1P34SF73V 1P34S*73<*

DO iOU nAVF AMO 1 HKh DATA bFT ? i Oh Ms TABLE A3.18. in 1 5 nnOGHAM WILL, F h I MT A CKAi-H FOH LINEAR AND A WEIGHTED SOUND LEVELS FROM fAfER TALE WITH DATA FOH CHANNELS 13 TO A3

IN'i EGnAT I ON 1 1 ME ? 1 A SECONDS .

DESCH1 F'flON? SOUND INSULATION TFST NO. 1. BACKS. Of IND NOISE SPECTRUM . HECEIVINA ROOM A.

LOAD I'AFE AND SET TO START

: 13 • Lv.- • 0 0 SL L 0 • 0 3 = 1 3 » 0 0 = O * V.* V.1 = Lv.' .V.’ V.- 1 A 0 5 7 • L 5 =. 57.L5 = 1 A • 0 0- = 0.0 0 = 57 . L5 1 5 053.00 5 3 .00 = 1 5 • 0 0 = 0.0 0 = 5 3.00 1 6 0 3 5 . L 5 35•L5= 1 6 • v_- = A 0 • o 0 = 0.65 1 7 0 3 6 . L 5 S 36.25= 17 • 0 o = C' .00 = 6.0 5 13 035.50 S. 35.50= 13.00= O . V.' V,* = V . 30 1 V 0 a 1 .50 =. Al.50= 1 V . 0 0 = 0.0 0 = l v. o o LO 0AL.L5 s AL.L5= L v.' . v.' v_' = 1 0 V.* •• V.' V.* = L3 • 15 LI 0 A 6.7 5 n 5 A A . 7 = LI.00= 1 L 5.0 0 = 30.65 LL 0A7.0 0 =L A 7 • v,' v = L L . 0 0 = 160.00= 33.60 L 3 0 A 5.7 5 SL AS.75= L3.00= L i»* 0. 0 0 = 3 A . 3 5 LA 0 A 6 . L 5 n A^.ri 5 = L A . 0 0 = L 5 0.0 0 = 37.65 L 5 0/17.75 ZL A7.7 5 = L 5 • 0 0 = 315.00= A 1 . 1 5 L 6 A3 • 00 s. AS • v»- v.- = L 6 .00 = A v.' c • v.' v.' = A3 . 20 L 7 0 A 6.7 5 =. A 6 . 7 5 = L7.00 = 5 V.' V.' . 1*' V*' = A 3.5 5 L3 0 A5.60 ss A 5 • 5 0 = L >5 • v.’ v.' = 6 30*00 = A 3 • 6 0 ri ^ 0 A A • 5 0 r. AA • 50 = L ^ . v.' vj = 3 0 L' » V.' V.' = A3.7 0 30 0 A3 . so­ A3.50 = 30 • v.- ^.- = 1 • o v.- = A3.50 31 on a . LS =. AA.L5 = 3 1 .vjv.' — 1 L * c- o = A A . 3 5 3L 0 A L . 2 5 AL.L5= 3 L . <** v.- = 1 6.0 0 = A 3 . L 5 3 3 0 61 1 .25 A i .25 = 3 3 * v v.' = L * 0 0 = AL . A5 3 A 0 3 3 . L 5 ZL 3 3 • L 5 = 3 a . v.* v.' = L5.00= 3 V . 5 5 3 5 037.50 Z. 37.50= O 5 . v.' v.’ = 3 L • c v.' = 33.7 0 3 6 0 3 5.75 = 35.75= 3 6. 0 O' = A . V.* v.' = 3 6.75 3 7 0 30.L 5 n 3l- . L 5 = 3 / * v»- v.' = 5 . v.' 0 = 30.7 5 33 0 L 6 . L 6 n L6.L5 = 35 . v.* 0 = 6 A.00 = L 6 . 1 5 3 v 0L3.75 z L3.75= 3 V . 0 0 = 3 . i_- v.' = LL.6 5 AO CL1.75 z Ll.75= Ac . v.'0 = 10*00= 1 V • L 5 Al OL1.75 LI.75= A 1 .00 = 12.00= 1 7 . A 5 AL 0L0.50 =. Lv." . 50 = A L • 0 0 = 16.00= 1 3. VC- A3 0 L 0.0 0 = Lv»- • v.- v.' = A 3 • 0 0 = L 0.0 0 = 10 * 7 0 HETURN TAfE HFADEn TO STOP

Key- Column 1 - linear Column 2 - channel Column 3 - frequency Column 4 - A-weighted levels Column 5 - linear Sound Insulation Test Ho, 1. Background Noise Spectrum. Receiving Room 4. 1o Sec. Integration Time.

Fig. A3.19.

DO x OfJ nAVF ANOTHEh DATA SFT ? l Oh NsN TABLE A3.20. IVlEPnATiO'M i IMF.? 32 SFCO\]DS

DE LCnlr i 1 1 y? SOUND 1 MSULA i I ON] T FS I MO . 2 . FAC KHOI JMD MO i S F 31-FC T r ' i y . SOUhCF HOOM 2. (WHEN COMPRESSOR IS UN)

LOAD iAfE A \i 1) SET TO 5 TAhT

: 13 :027 • c- v.< — 2 / • y- v»- = 1 3 . 0 0 = 0 • 0 0 = 2 7 .v.’ v_- 1 A 0 6 3.6 0 zl f'ih m 5 0 ~ 1 A *00 = 0 • 0 V.' = 63 . SC- 1 5 0 s 2 » 0 0 52 • 00- 1 5 • 0 0 = 0 . 0 0 = 52 • 0 0 1 6 0 S3.so 53-50= 1 6 . 0 0 = AC­• 0 0 = 13. v 0 1 7 0 4 1 • S 0 A 1 .50 = 1 7 . 0 V.' = S' . 0 0 = 1 1 . 30 13 046.75 - AA.75- 1 3 . 0 W' = 0 .00 = 20.55 1 5 0 s 3.2 6 53 .25 = 1 V • 0 0 = 0 .00 = 3 5.75 20 0 6 7.7 S ZZ 57.75= 20 . 0 0 = 1 0 0 • 0 0 = 33.6 5 21 0 4 7 • S 0 ZZ A7.50 = 21 • 0 v_. = 1 25 • 00 = 31 .AC- 22 0 4 3.2 S

ZL 43.25= 22 . 0 0 = 1 60 . 0 KJ = 34 .35 2 3 0 4 4*0 0 ZZ A A • 0 0 = 2 3 • v.- 0 = 2 0 0 . 0 0 = 33.10 24 0 4 S . C 0 — A 5 • 0 0 = 2 A • C- C- = 2 50 . 0 0 = 36.40 25 0 3^.25 ZZ 3* • £5 = 25 • 0 0 = 31 5 . 0 V.' = 32.65 2 6 0 3 a • SC- ZZ 3A.50= ' 2 6 . 0 = A 0 0 • 00 = 2 V . 7 .0 27 037 . SC- = 37.50= 27 . 0 0 = 500 • 00 = 3 A . 3 0 23 033 . SC- zz 33.50 = 23 . 0 0 = 6 30 . 0 0 = 36.60 2.y 04 2.7 S ZZ A2.75= 2 V • 0 0 = 300.00 = A 1 .VS 30 0 4 4.S 0 ZL AA•50= 30 • 00 = 1 .00 = A A . SC- 31 0 4 4.7 s ZZ AA.75= 31 .00 = 1 2 • 00 = 45 . 35 32 042.26 ZZ A2•25= 32 • 0 0 = 1 6 . 0 0 = A3.25 33 04 1 .7S ZZ Ai.75= 33 • 00 = 2 • 00 = 42.*5 34 040.2 S zz Av*‘ .2 5 = 3 A • 0 0 = 25. 00 = 41.55 35 034.00 3 A . 0 0 = 35 • 0 0 = 32 • 0 0 = 35.20 36 036.25 zz 36.25= 36 • 00 = A . 0 0 = 37.2 5 3 7 034.75 z. 3A.75= 37 .00 = 5 • 0 0 = 35.2 5 33 031.25 n 31.25= 33 . 0 = 6 A .00 = 31.15 3* 027.50 =. 27.50= 3* • 00 = 3 • 00 = 2 6.4c- 40 v.- 2 7 • c- c- ZZ 2 7.0 0 = AO . 0 0 = 10 . 0 V.' = 24. SC- 4 1 027.00 ZZ 2 7* 0 0 = Al .00 = 1 2 • 0 0 = 22. 70 4 2 027.00 ZZ 2 7 . v.' c- = A2 . 0 0 = 1 6 . V.’0 = 2 c- . 4 c- 43 0 2 7 *00 zz 2 7.00 = A3 • 0 0 = 20 .00 = 17.70 rtETUHN fAFE FF.ADFh TO STOr

Key- Column 1 - linear Column 2 - channel Column 3 - frequency Column 4 - A-weghted levels Column 5 - linear Fig. A3.21. SOUND I NSIJLAT.I ON TFST NO. 2. BACKhOUND MOISF SPFCTnlW. 50UHCF ROOM 2. (WHEN COMPRESSOR IS ON)

SOUND rhFSSUHF. LF.VFL DP 2 G = 3 G = 4 G - h G - fC = 7 G = .3 G 12343673* 12345-673* 12345673* 12345673* 12345-673* 12345673*

DO iOU riAV/F. A'NOTHFH DATA SFT ? x OR N:\| TABLE A3.22. INTFGHAT10N TlfoF.? 32 SECONDS.

DFSCHiFT I OiM ? SOUND INSULATION TEST \m . 2. PACKHOUND \iOISF SFFCTPUM • B.FCFIVINO HOOK 1. (WHEN COMPKESSOH 13 ON)

LOAD TAFF AND SET TO ST AFT

: 13 : 0 2 7 . 0 0 ZZ 2 7 • kw1 k.- = 1 3 • 00 = 0 • V_‘ w = 2 7 . 0 0 1 A :0 6 3* 76 n 63.73= 1 A . 0 0 = 0 • V.' V.' = 6 3 • 7 3 1 6 :060.26 50.23= 1 5 . V.< V.' = 0 . c v.' = 50 • 25 1 6 i0 60.00 - 50 . L- Lr — 1 6 .00 = a0 • 00 = 1 5 • AC- 1 7 : 0 A 3.6 0 r: A 3 • 3 0 = 1 7 . o 0 = 0 . V.' V.' = 1 3 • 30 1 3 : 0 3 3.26 = 3 3 * 2 3 = 1 3 . 0 0 = 0 • l.' V.- = 1 2 • 0 5 1 7 : 0 6 7.2 3 - 57.25= 1 9 . 0 0 = O' . L'k»' = 3 A • 73 20 : 0 A 5.2 6 - A3.23= • V_' k.' = 1 00 . 0 0 = 27 • 1 5 2 1 i v.’ A 3.6 ZZ A3.50= 21 . V.- V.' = 1 23 .00 = 32 • A 0 22 ! v.' A 7 . V.- c - A7.00= 2 2 . 0 0 = 1 6 0 • 00 = 33 • 6 0 2 3 : 0 3 7.2 c - 37.23= 2 3 . 0 0 = 2 0 0 . V. k.' = 2.6 • 3 5 2 A :0 3 6.75 = 33.75= 2 A • i.' 0 = 250 . 0 L' — 2 7 • 1 6 2 5 :0 33.60 = 33.50= 23 .00 = 3 1 5 . 0 O' = 2 6 • j 0 2 6 : 0 3 5 . r'0 - 33.50= 2 6 • V.1 V.' = ACC . 00- = 23 • 70 2 7 :0 3 7.76 =. 37.73= 2 7 . 0 0 = 500 . 00' = 3 A . 5 5 2 = :0a 5.2 6 - A 3 • 2 3 = 2 * V.' V.* = f 3 0 . v.' v»' = A 1 . 3 5 2 y J 0 3 ■ *> • k. v n 33•00 = 2 V • V.' V.' = 3 0 0 • V.1 V — 3 7 . 2 0 30 ! v A 1 •». ».• = /i l . 00 = 30 * V.' V.' = 1 • V.' = A 1 • 0 O' 3 1 : o a a . r. c - /\ £1 • v.' V.' *” 3 1 . 0 V.' = 12 . k_» k_' = n A . f 0 3 2 : 0 A 2.7 6 = A 2.7 ^ = 3 2 .00 = 1 6 • 00 = A3 • 7 6 3 3 i036.00 = 3 f .00 = 3 3 • 00 = 2 * V.' 0 = 3 7 • 20 3 A : 0 3 3.7 6 = 33.75= 3 a * V.1 V = 2 5 • V.' V.' = 3 5 • 0 6 3 6 : 0 30.6 0 30.30 = 3 3 .00 = 32 . 0 0 = 31 • 70 3 6 : 0 3 0 • 6 0

- 3 o . 3 v.' = 3 6 • 00 = A . C V' = 3 1 • 60 3 7 :030.60

= 30.50= 37 .00 = 5 » V.' v.' = 3 1 • 0 0 33 * 2 7 . V.-v.'

2 7.0 0 = 33 • V.' V_' — 6 A . c 0 = 2 6 • y 0 37 * v. 2 7 . k. ■ ^ • = 2.7 * k.< 0 = 3y • V.* <^' = 3 • 00 = 25 • y 0 AO : 02 7.00

2 7 . V.* c = A 0 . 0 0 = 1 0 • V.’ k.' = 2 A • 50 A 1 * k.' 2 7k.'

= 2 / . u v.' = A 1 . 0 0 = 1 2 . L- = 22 . 70 A 2 5 v.- 2 7 . k.- k_-

- 27.00= A 2 . 0 0 = 1 6 . V.' L- = 20 • AO A3 I w 2 7 • k.' v.'

r: 2 7 • v.' v.' = A3 . 0 0 = 20 . 0 k.- = 1 7 • 70 BFTUaN TAi-F HFADF H TO STOP

Kex- Column 1 - linear Column 2 - channel Column 3 - frequency Column 4 - A-weighted levels Column 5 - linear Fig. A3.23. SO IMP i NJHJLATI nv I'FF'l MO. P. PACKhOHMD MOISF SHFOTPOV. HFCFI VINJO pnnv, 1 . (..HEN COMPRESSOR IS ON)

b 0 U\JD riiFSSlJHF LFVFL DP

HO - 30 = AO - SO = *0 - 70 = 30 1H34S673V lH343f73* 1^345^73^ 1H34SS73V 12345*739 12345*739

linear A-weighting

70 = 30

DO lOU HA v'F AMOTHFH DATA SFT ? V OH NJ: \J * APPENDIX 4

loo —■ lo BrOel & Kjcer BrOel & K|«f

2000 10000 20000

A4. a. Checking the response of the microphones.

A4. b. Airborne Sound Pressure Level differences between the source and receiving rooms.

A4.1 G o-/o —*J«----- ao-20 BrU.I & Kj<*r

100 200 1000 2000 10000 20000

A4. c. Impact Sound Pressure Levels in source and receiving rooms.

A4.2 APPENDIX 5

Conversion of Linear to A-weighting*

Channel Frequency Hz A Correction

14 25 -44.7 15 31.5 -39.4 16 40 -34.6 17 50 -30.2 18 63 -26.2 19 80 -22.5 20 100 -19.1 21 125 -16.1 22 160 -13.4 23 200 -10.9 24 250 - 8.6 25 315 - 6.6 26 400 - 4.8 27 500 - 3.2 28 630 - 1.9 29 800 - 0.8 30 1000 0 31 1250 + 0.6 32 1600 + 1.0 33 2000 + 1.2 34 2500 + 1.3 35 3150 + 1.2 36 4000 + 1.0 37 5000 + 0.5 38 6300 - 0.1 39 8000 - 1.1 40 10000 - 2.5 41 12500 - 4.3 42 16000 - 6.6 43 20000 - 9.3

* Linear weighting + A Correction = A-weighting. A5.1 APPENDIX 6

Sound Insulation Measurements for Concrete Floor

Constructions Between Dwellings in NSW Housing

Commission Flats.

A6.1 tfl I o •—» TJV-i 4-1 i—I load-

walk-up

brick

4-storey slab ,

I O Plan

4-1

5"

f la t. Typical bearing

.2. A6

Fig.

4-1 OJ

cladding, u n i t s .

aged

ex tern al

3 0 - s to r e y precast

w alls.

P la n

slab ,

in te rn a l F lo o r

concrete

in -s itu 6 T y p ic a l

A 6 .1 .

F ig . Sound Transmission Loss Fig.

A6.3.

J Average 12 ----

No.

£

(STC Sound 6"

48). slab

Transmission

14

No. 1000

(STC 1600

Loss

52.5);

Frequency for 2500

concrete j> --- 4000

J Hz

5" floors.

slab Normalised Impact Sound Pressure Levels Re: 0.0002 dyne/cm^ Fig. 100

P6. 125 4.

160 ‘ Average (IIC

200

250 35.5);

L 315 n

0 800 500 400 for

concrete 630

5"

1000

floors. slab 1250

1600 00 3150 2000 7

No.

4 ---

Frequency 2500 (IIC 4

4000 6" 33).

slab 5 Hz

7

No. 40 80 60 70 50 30 20

Impact Insulation Class - IIC . ti 12 - -

o 1

i. ±

= Hz

S floors

floors floors floors frequency

Coocreie concrete concrete

concrete concrete

" 6" 5 for 6"

5*

for for for for

One-third-octave Tests Tests Tests Tests

T>e,v?arUoos a»tioo

Insulation Insulation Insu

JnsulatTon

Sound Sound S-i^ode^rd Sound Sound

Impact Airborne /Airborne FT6.A6.5.

SaoCianlojJ. |]v ye aorp?iAap pj'epO'cqs TABLE A6.6. Airborne Sound Transmission Loss for 5" concrete floor* (60 psf) covered with vinyl tiles i vo rs 00 ON •H *H st m O •H CM on •H CM

i I — h o u o CO x i cr* >N h aj Cd u 0) <1- rH o o VO o vo vo CM VO CM CM ON st HrH rH co O co CO CO CO CO CO rs rs is CO CO CO CO ON co st VO o rH st m CO CO ON rs 00 oo CO CM rH rH CO m m CO m m is VO CM CM ON on m CM • • • • • • • • • • • • ♦ • • • • •

st CM co o o vo vo m co m st CM CM CM rs CO CM rs co CO CM <1- CO CO CO CTN rs CO CO CM I''. Is o o co rH st <1- CO CO CO CO CO rs m rH co 00 rH rH vO CM OCO CO o m CO CO • • • • • • • • • • • • rH VO rH o CO vo is st vo CM is is st MCM CM CO st CM OON CO CO CO CO CO co CO is CO co CO CO CM is rH rs CO CO CO CO CM OO CM rH rH ON is CO o CM CM m CM rs m • • • • • • • o MCM CM o *H CM co rs rH st vO rH rH CO vO O vo CO o is CO 00 oo co rs rs is CO CO rs co m 00 00 CO CO CO l". ON st CO co is CO o CO CO CO I"'- O VO vo rH CM ON OCO CO m * • • • • • • • • • • St St O CM OO rH <1- < 00 OCO CO o o 00 00 00 St m CO CO co oo CO CO co rs in CO CO m CO CO CO ON OO 00 o in OO CO rs co is 00 co o o CO co rs rs 00 rH rH vo in co co rs ON CM vO 1 • • • • • • 9 • • • • • - rH si- st CO m o CM rH 000 00 rs co oo rH ON rs in ON st st co CO is rs CO m CO o oo rs ON O st CO m CO rs CM CM st o CM o rH st vO o co CO rs o o o ON • • • • V • • • • • • • • St St St St St st St rH St rH St vo St vO vO St o o St St CO CO CO CO rH vO CM St St CO CO ON vo is St O CO CM ON O CO St St St st co O O O CM vo vo CM Sl" OCM OO IS o j* • • • • • • • * • • st st O O st st rH st st m O vO O st vo St CM 00 VO oo VO o rH CM st st CO co CM rs vO vO st st St CO vo m CO CO CO co St St m CO co CO o o CM ON ON St St St CM Hr rH rH rH IS • • • • • • • • • • • • • • st vo st vO vo vo rH st st st st st St vO vo oo VO rH St st CO 00 o st st co ON m IS CM rH st vo vO rH CM is co rs st CO st st ON co CO ON st CO vo o m CO vO • • • • • • • • • • • • • st 00 o -4- 00 o ON 00 00 st VO O st st st st rH st 00 o m CM 00 rH CM st st CO CO vo vO st st vo st st rs 00 rs tst st in OO ON rH st st CM m st m m m is rs CM m rH is • • • • • • • • • • • o o st rH o o 00 St St st o rH CM m rH rs CM o rH CM m CO ON ON m m o is ON vo m m rH rH st st vo m CM o m m m o CM st m o CM 00 St ON «H ON is rH m o o o CO CO • • • • • • • • • • • rH St CM 00 CM O St rH in m co CO 00 rH rH rH m co rs m CO CM CM CM st m st St m vO rH rH m m m m m rs ON co CM St m ON CM St ON st m CM CM st OCO CO m m rs rH rH 00 CM • • • • • • • • • • • • • • o o rH vo rH st CM rs r-H O st o st in m m IS 00 m m m o CM CM rH rH m st st in in CM oo vo st m co rs in in CO m m st st vO CO CO ON st in rs m vO rs rH CM co rs • • • • • • • • • • St o o CM o rH o m m co rs CO IS ON IS CM CM oo 00 St st rH • CO co IS IS m IS in m IS m CM vo st in CO m CM m m m m m vO St m rs rs CM vo m vO vO vO m m co m m • ♦ • • • • • • • • • • St St o o o o o CM rH rH VO st rH m IS m IS m CO CO IS co rs rH CM vO ON m m m CO m m m CO m m m oo IS IS vO st m m CM m m IS ON st st st rH rH m rs CM m m CO • • • • • • • • • • • • • • • • • st rH st o vo vO vO vo o CO m o m IS in IS o vo o m vO rs o vo m m is vO vo CO 00 m 00 co IS co m 00 ON 00 00 vo m CO is is o o m m CO m is CM ON m 9 • • • • • • • % st o o m vO vo IS m CO m IS vo vo OO VO VO vO o m CO m m ON is o IS o 00 o vo vo vo o 00 vO m rs ON CO rs rH VO o m ON m vO rH iH St CO m ON co vo • • • • • • • • • • • o m o o o vO vO vO vO rs m CO CO m OO vO vo vo o vO vO m is CM is o rH o vO o oo vo CO rs ON CO is rH 00 VO rH m rs VO CM st is CO CM m ON in ON ON CO • • 9 • • • • • • • • St ovo St vo st st O ON ON st St m rs oo OO st st ON st co H o CO ON ON st st IS 00 00 rH rH CM vo st st co co m CO 00 St st st x CO 00 ON rH rH < < CO CO 00 pq CQ CO oo co 1

Iclo St 14-1 oo CO C H o •H vO CO M 00 u 0 > cd d) o d) X rX z X •H X X 1 rH rH •H •H rH x: •H rH 4-4 no <; •H 1 TJ 4-4 { Pd •H T3 ■Tl rO — 4-J 4-1 4J •M ■u — 4-1 ■u h •• u CO CO CO co CO cd a £ o o u cd cd dJ 0 a dJ 6 (0 a aj § d) CO CO CM CM I/O • • • • • • • • • • • • • • • • • • • • mt Mt Mt Mf MCM CM CM CM 00 im r-H - CM 00 CM UO — H • • • • • • 0 • 0 • • • • m r-H o Mt r-H Mt Mt vO o im vO o r- r r-H vO r-H CM vO 00 oo cr. m im 00 cr. cr. o UO cr. cr. uo uo UO UO uo im vO 00 uo uo co UO UO im CO UO uo uo uo m co vO O r-H m 00 uo CM m im CO CO o CO CO — H • • • • • • • • • • • • • • • • • Mt o Mt Mt Mt r-H Mt O Mt MCM CM o o 00 im UO im 00 O I'-' 00 O oo 00 O l". vO vO vO uo UO CO vO OO uo uo UO O'. uo CO uo cr. uo CO uo uo uo uo CO uo in vO VO UO CM uo CO CO UO CM o oo uo in UO • • • • • • • • • • • • Mt Mt 00 vO r-H o VO Mt vO vO vO vO vO vO VO VO 00 vO O vO r-H r-H o o vO CM |M UO im o o vO CM cr. o CM CM cr. vO CM vO 00 oo uo CO |M o r-H O t-H UO uo CO CO CO UO uo VO uo uo uo im uo im 00 VO r-H r-H I'M uo 00 uo • • • • • • • 0 • • • • • • • • • Mt Mt Mt vO vO vO vO oo VO r-H vO OO vO r-H cr. CM vO r-H 00 VO Mf vO |M vO vO o CO rM CO vO vO vO O r-H t o UO uo UO co CO co o O CM CO CO CO CO uo CM vO vO o vO ON vO r-H cr. co uo CO UO CO co — H • • • • • • • • • • • • vO OO VO 00 vO vO VO VO Mt Mt Mt O O O vO vO vO 00 00 vO vO VO Mt VO r-H vO vO o vO vO vO vO vO co O cr. VO VO VO vO VO VO r-H |M uo CM 00 CM 00 |M IM co oo o r-H CM CO r-H uo CO |M o CM t UO CO UO — H • • • • • • • • • • • • • • • • • • Mt o vo vo r vo r oo r-H vO VO VO o o cr. CM cr. 00 cr. CM |M o rM o co cr. VO |M |M r-H o o o O O VO Mt CO UO CO vO vO Mt uo uo in CO vO |M vO CM uo uo CO r o vO |M cr. O VO CM — —

H H • • • • • • • • * Mt Mt Mf CM Mt Mt uo UO uo CO CM CM r-H UO uo UO CO in CO uo in m CO UO UO CM CO UO uo UO H o o oo uo Mt Mt Mt Mt Mt O t-H Mt Mf cr. OO oo vo Mt uo OO uo r-H o o uo 00 cr. UO CM uo uo IM 03 < PQ pq i ICO CO t-H cr. CM CM UO CO uo o H 1

cd > 60 u o cu l-i cd a • X •

FHA Results: Similar thickness but with 5/8" mastic asphalt on top and 3/4" plaster ceiling: Laboratory STC 47 r r — £ cd CO — ^ I

TABLE A6.8. Normalised Impact Sound Pressure Levels for 5" Concrete Floor* (60 psf) Covered with Vinyl Tiles I

x X cn r-H IN CN a a aj cr 0 C O Pn d J vO vo NT vO vO cn vO -Xl" r oo co — n m cn r VO vO

NT CN vO Nl- vO > vo vO NT n CN in cn cn cn CO iH VO vO Nf m m ■ in vO • H CO H — — — • i i - ' i

n VO vo Nf vO n vo n vO m vo cn vO OO « vO n o m m m m m vo |N vO vO m vO VO o CO o O — }- J- T • I

XT vo N- vO cn n CN oo vo vo cn o o vo cn vO vo vO m m n cn O vo <1 OO 00 -sf m vO VO in m o oo oo

xr

Nf Ni- N vO vj vo CN vo m o oo cn cn xf vO oo m vo oo fN H Nt cn m vo IN CN vO cn vO O — h m m m cn io

OO vo vo

xr vO ON n N rH vo o o cn cn cn IN O O CN oo MO o in OO IN cn vO o m cn cn in IN O O CO o cn I-

vO oo VO vo m cn oo vo cn cn I O CN oo cn N o o m CN 00 o vO <■ m cn cn cn VO m VO m o m m n

vo

vD VO vO cn o cn cn vo cn vO cn cn 00 IN cn VO oo OO H vo m oo cn vO VO cn cn m cn

•si -Xl" n VO H oo o cn vO vD O cn fN o cn IN oo cn vO r-N o o r-N O cn O CO CO fN o n O ■-4 o CO in cn I- n •

vO Nl vO vO VO o VO o o vo o o o o m O * m OO cn cn cn cn oo fN cn oo vO in O OV cn CN cn n o cn — • ” l

<

VO vO vO vO o vO 00 o o vo CN o CN o oo f vO I cn oo cn cn oo CN oo m vO vo cn 00 CM vo o m m o n — 1 • 4 "

vO 00 vo i N vo N vO •-4 o o r-N O H vo — IN O ? vO vo vO in oo vO cn vO CN vO cr\ O IN O oo rN cn Cn cn mom — l •

i

I vO vo i Nf vo sf VO vo vo -xf CN vO vo N- vO vO n VO CN o o o oo cn 00 cn < r-N VO oo n IN O Cn r-N n in — — 4 •

I

cn

cn

I vO vo i N IN oo vo VO vo vO CN o vo n VO 00 vD vo vo N vo vo CN vO h. O VO O vO O m o — * O m h ( • n -

vo vO cn — o m cn vo vo oo vo vo cn vo cn vo n oo vo vo o vO vOsf 00 moo m m o cn cn vO o cn IN m in o rv. m mom m . • • 4

vO vO co

4 <1- vo < oo vD CN 0 cn vO o cn vo vo CO o oo o m m m m co 1 m cn o oo vo vo - vo n h

• . H vo vo • vO O CN o 0 o o *-< o cn vo o m rv m m cn m cn m o o m vo .-4 cn h O m o in •

• •

nj -vi cn cn CN vt cn CO CO cn cn cn m cn co co co m M w u - ­ l

14-1 cn M <5 cn M o 00 QJ M 03 aj u X 4-4 T r rH X 3 rH 1 •H •H X X rH rH X 3 pc! •H 5 •H 4-1 4-1 4-> — 4-1 4J 4-1 4-1 — & co CO u CO >-l cd QJ CO cd CO I g QJ OJ g a cu £ O a) 1 0 Ci d d 3 I I

Nt 4-4 MO X X i •H nd •H X M M •H u X 4-1 — M oo J-4 u ft cd ft QJ QJ 1-4 o cd H QJ cd o rH QJ a cd o O I

* Building system as TABLE A6.6. TABLE A6.9. Normalised Impact Sound Pressure Levels for 6" Concrete Floor* (80 psf) Covered with Vinyl Tiles. I

H CO X vo P Po G cr 0) G u G cu G m 1 Mt mt mt rH vO r cn oo vO CM m 00 o H r-^ CT. o CM OO CM r^. vO cm o m CO m in m in o m m m LO — H • • • • • • • • • vO vO VO vO vO vO Ooo vO vO CM CM m oo r^. 00 OO I"". r CM CM CM r-H oo r cr. r-H CJv vO o co m m CT. CTv CM m CM OO m — — H • • • • • • • • • • 1 vO OvO vO Mt vO VO Mt vO CM r-H CM vO vO r-H r-H mt 00 CM r-H vO o cr. vO OO r>. 0O OO OO m oo 00 o O • • • • • oo OvO VO r-H vO r-H CM CM vO vO Ml- vO r-H oo oo oo m 00 0O OO r-H vO MCM CM CM 0O 0O CM O O cr. cr. m cr. CO cr. CO vO oo • • • • • • • • • • • • • r-H vO OVO vO OvO vO vO vO vO r-H vO vO CM rH Mt Mt CM O O'- r-H vO r 0O vO 0O OO OO m 0O 0O 0O vO CM cr. CM 0O m m —H • • • • • • vO Mt Ml" r-H vO Ml- Ml- r-~ vO vO vO VO r-H CO cr. oo r-H oo r oo in m CM CO m m CM o m m — H • • • • • vO vO vO vO vO vO vO O vO O o CM vO vO Ml" O vO vO f-H vO vO 00 O o 00 m m in in m m m CM m r-H o o Mt • • • • • • • • • • • • • • Ml" VO Mf vO VO vO o vO vO o vO r-H vo vO o o m o O r-H vO o o o vO VO oo m m r-H r-H o o vo 00 in O o m vO ON 0O 00 m • • • • • • ovO vo vo O VO O vO vO vo vO vO vo vO vO O m m o O vO vo VO 00 00 cr. m m m m o 00 OO m CM • • • • Mt r Mt ov vO vo vo ov ovO vo vo vo vo vo vO Ov vO vo vO vO r-H oo Mt r-H f-H vo f-H oo OO o ovD vo cr. cr. cr* t". r» O o o m m 00 vO — H • • • • • • • • • • • OvO vO r-H Mt Mt Mt vo o cr. vO r-H CM vo r O VO vo 00 - r-H f-H o r^. in m CM cr. cr. vO vO vO o o o in oo n* — H • • • • • . r-H Mt f-H Mt vo r-H CM o o f-H vO cr. vO vO vO vD CM vO vo vO r-H m m m m cr. m r t m oo vo

— — H H • • • • • • • • Mt VO vo vO f-H r vo t vo vo vO o oV vo VO vo vD OO 00 o r-H vO oo o r-> CM CM CM vO oo OO vo 0O vo vo O0O OO VO r~- CM o r-. OO — — H H • • • • • • • • • • • • • Mt Ooo OO OVO VO vO vo vo vO vO vO ooo oo 00 vO vO vO o O O OO vO MCM CM o vO vo VO VO oo r-H OO OO vO m oo o O cr. m • • • • • oV vO VO Mt vo Mt vO Mt vo vo vO Mt vo Mt Mt vo 00 oo vO Mt vo r-H 0O vO vO vO m 0O VO O O O'- m m • • • • • • Mf r-H Mt VO Mt vo CM r-H CM CM r CM Mt vO vO vO vO 00 Mt CM CM o r vO r r-H m CM CM m cr. 00 oo m o m m — — — •

H H H • • • • • • • • • • • • • • • • , r vO r Mt vO OvO vO M00 vo CM 0O r-H VO cr. r-H r-H n. Mt VO r-H vO CM r r-H vO VO VO CM r CM CM o o O O O 0O OO — — — — H H H H • • • f-H rH r-H 00 vO CM CM CM oo vO f-H CM CM m cr. cr. 00 r cr. CM vo o r 00 f-H m m oo vO o m m m o m — — H H • • • • • vO OO vO o r-H Mt OO OO m OO oo in m cr. oo m oo m m OO in M w o • • • I 1

r-H r-H 00 4-1 OO m m M M <3 c_> u 0 CO > u 00 a) o ii X! in x: rH P rH •H •H •H •H •H < Pd Pd 4-> ■U ■u 4-1 4-1 4-1 ■M 4J • U co o ctf cd M CO s 0 cd co CO a, G 0u a) CO CO CO 0 cd a G

• r-H rO OO •H rH •H w w H o 4-1 00 cd o u M aj G cd O a 1

•K Building system as TABLE A6.7. REFERENCES

Books

1. Alexandre, A., Barde, J. Ph., Lamure, C. and Langdon, F.J. (1975) Road Traffic Noise. Applied Science Publishers. Chap. 1-3.

2. Anthrop, D.F. (1973) Noise Pollution. Lexington Books.

3. Beranek, L.L. (1954) Acoustics, chap. 10-13. McGraw-Hill Book.

4. Beranek, L.L. Ed. (1960) Noise Reduction, chap. 20. McGraw-Hill Book.

5. Bragdon, C. (1971) Noise Pollution. Pennsylvania University Press.

6. Burns, W. (1973) Noise and Man. William Clowes & Sons.

7. Bazley, E.N. (1966) The Airborne Sound Insulation of Partitions. National Physical Laboratory, H.M.S.O.

8. Clark, G.M. (1971) Statistical and Experimental Design. Edward Arnold Publishers, London.

9. Crocker, M.J. and Price, A.J. (1975) Noise and Noise Control, volume 1 CRC Press.

10. Day, B.F., Ford, R.D. and Lord, P., Ed. (1969) Building Acoustics. Elsevier Publishing.

11. Diamant, R.M.E. (1974) The Prevention of Pollution, chap. 9: Noise, pp. 246-265.

12. Evans, E.J. and Bazley, E.N. (1966) Sound Absorbing Materials. National Physical Laboratory, H.M.S.O.

13. Harris, C.M. (1957) Handbook of Noise Control, chap. 9,10,11,19,20,22, 39 and 40. McGraw-Hill Book.

14. Kerse, C.S. (1975) The Law Relating to Noise, chaps. 1,2,3,5,6,8 & 9. Oyez Publishing, London.

15. Lawrence, A. (1970) Architectural Acoustics. Elsevier (Applied Science Publishers.)

16. Parkin, P.H. and Humphreys, H.R. (1969) Acoustics, Noise and Buildings Faber and Faber, London.

17. Pearson, E.S. (1935) The Application of Statistical Methods to Industrial Standardization and Quality Control. British Standards Institution. No. 600. Section 6, pp. 51-71.

18. Peterson, A.P.G. and Gross, E.E.Jr. (1972) Handbook of Noise Measurement. General Radio.

19. Rettinger, M. (1973) Acoustic Design and Noise Control. Chemical Publishing, New York.

R(l) 20. Watters, A.A. (1975) Noise and Prices. Clarendon Press.

21. Weston, E.T., Burgess, M.A. and Whitlock, J.A. (1973) Airborne Sound Transmission Through Elements of Buildings. E.B.S. Technical Study 48, Sydney.

Standards and Recommendations

22. Sound Insulation of Traditional Dwellings - 1. Building Research Digest 102, February 1969.

23. Sound Insulation of Traditional Dwellings - 2. Building Research Station Digest 103, March 1969.

24. Sound Insulation: Basic Principles. Building Research Station Digest 143, July 1972.

25. Harper, F.C., Warlow, W.J. and Clarke, B.L. (1961) The Forces Applied to the Floor by the Foot in Walking. National Building Studies Research Paper No. 32, H.M.S.O.

26. Parkin, P.H., Purkis, H.J. and Scholes, W.E. (1961) Field Measurement of Sound Insulation between Dwellings. National Building Studies Research Paper No. 33, H.M.S.O.

27. Sound Insulation and Acoustics. Department of Scientific & Industrial Research, Post-war Building Studies No. 14, H.M.S.O. 1944.

28. House Construction. Department of Scientific and Industrial Research, Post-war Building Studies No. 1. H.M.S.O. 1944, pp. 20-26.

29. Impact Noise Control in Multifamily Dwellings. FHA No. 750. Federal Housing Administration, Washington. January 1963.

30. A Guide to Airborne, Impact and Structure-Borne Noise Control in Multifamily Dwellings. U.S. Department of Housing and Urban Development, Washington, D.C. September 1967.

31. Minimum Property Standards for Multifamily Housing, FHA No. 2600. Federal Housing Administration, U.S. Department of Housing and Urban Development, November 1966.

32. Noise Abatement and Control: Department Policy, Implementation Responsibilities and Standards. U.S. Department of Housing and Urban Development Circular 1390.2, April 1971.

33. Architectural Acoustics - Draft for Field Measurement of the Airborne Sound Isolation Provided by Building Elements. SAA, May 1975.

34. New South Wales Local Government Act 1919, Ordinance 70, 1974.

35. ISO Recommendation R140 - Field and Laboratory Measurements of Air­ borne and Impact Sound Transmission. International Organisation for Standardisation, Geneva, 1st. Edition, January 1960.

R(2) 36. ISO Recommendation R717 - Rating of Sound Insulation for Dwelling. International Organisation for Standardisation, Geneva. 1st. Edition May 1968.

37. Tentative Method of Laboratory Measurement of Impact Sound Trans­ mission Through Floor-ceiling Assemblies Using the Tapping Machine. ASTM Designation E492-73T, American Society for Testing and Materials, Philadelphia.

38. Standard Recommended Practice for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions. ASTM Designation E90-70, American Society for Testing and Materials, Philadelphia.

39. Standard Recommended Practice for Measurement of Airborne Sound Insulation in Building. ASTM Designation E336-71, American Society for Testing and Materials, Philadelphia.

40. Standard Classification for Determination of Sound Transmission Class ASTM Designation E413-73, American Society for Testing and Materials, Philadelphia.

41. Tentative Method of Laboratory Measurement of Impact Sound Trans­ mission through Floor-ceiling Assemblies Using the Tapping Machine. ASTM Designation E492-73T, American Society for Testing and Materials, Philadelphia.

42. Physical Measurement of Sound. American National Standard, ANSI. SI.2 1962.

43. B.S. 2750: 1956 British Standard Recommendations for Field and Laboratory Measurement of Airborne and Impact Sound Transmission in Buildings. British Standard Institution.

44. Sound Insulation and Noise Reduction. British Standard Code of Practice CP3, chap. Ill (1960). Sub-section: Laboratory and Field . Measurements, pp. 54.

Journals and Papers

45. Arni, P. and Borenius, J. (1962) On the Correlation of the Results of Airborne Sound Insulation Measurements Recommended by ISO and a New Method Based on the Research of Van den Eijk. 4th. International Congress of Acoustics, Copenhagen, Mil, pp. 1-4.

46. Allen, W.A. (1962) Criteria for Dwellings and Public Buildings from 'The Noise Control', H.M.S.0. pp. 359-371.

47. Belmondo, V.E., Hesbink, T.B. and Brittain, F.H. (1973) Ranking the Impact Sound Transmission of Wood-framed Floor-ceiling Assemblies. J. Acoust. Soc. Am., 53, pp. 1433-1441.

48. Beranek, L.L. (1949) Sound Transmission Through Multiple Structures Containing Flexible Blankets. J. Acoust. Soc. Am., 21, pp. 419-425.

R(3) 49. Beranek, L.L. (1957) Revised Criteria for Noise in Buildings. Noise Control, 3, pp. 19-27.

50. Beranek, L.L. (1956) Criteria for Office Quieting Based on Question­ naire Rating Studies. J. Acoust. Soc. Am., 28, pp. 833-852.

51. Beranek, L.L., Blazier, W.E. and Figwer, J.J. (1971) Preferred Noise Criteria (PNC) Curves and Their Application to Room. J. Acoust. Soc. Am. , 50, pp. 1223-1228.

52. Berglund, B., Berglund, U. and Lindvall, T. (1975) A Study of Response Criteria in Populations Exposed to Aircraft Noise. J. Sound Vib., 41, pp. 33-39.

53. Bhandari, P.S. and Choudhury, P.S. (1970) Impact Noise Transmission through Floors of Multistoreyed Buildings. Indian J. Tech., 8, pp. 101-104.

54. Bhattacharya, M.C. and Guy, R.W. (1972) The Influence of the Measuring Facility on the Measured Sound Insulating Property of a Panel. Acusjtica, 26, pp. 344-348.

55. Brandt, 0. (1962) Studies on Flanking Transmission in an Experimental Building. 4th. International Congress of Acoustics, Copenhagen, M35, pp. 1-4.

56. Brandt, 0. (1962) Sound Insulation Requirements between Dwellings. 4th. International Congress of Acoustics, Copenhagen, pp. 31-54.

57. Brandt, 0. (1964) European Experience with Sound-Insulation Require­ ments. J. Acoust. Soc. Am., 36, pp. 719-724.

58. Brittain, F.H. (1972) Experimental Evaluation of A Simple Method for Estimating Sound Transmission Class in Buildings. INTER-NOISE 72, Washington, D.C., pp. 77-82.

59. Bruijn, A.de (1970) Influence of Diffusivity on the Transmission Loss of a Single-leaf Wall. J. Acoust. Soc. Am., 43, pp. 667-675.

60. Burd, A.N. (1968) The Measurement of Sound Insulation in The Presence of Flanking Paths. J. Sound Vib., 7, pp. 13-26.

61. Burgess, M.A. and Harman, D.M. (1974) Single Value Rating Methods. Appl. Acoust., 7, pp. 57-64.

62. Cavanaugh, W.J., Farrell, W.R., Hirtle, P.W. and Watters, B.G. (1962) Speech Privacy in Buildings. J. Acoust. Soc. Am., 34, pp. 475-492.

63. Choudhury, N.K.D. and Bhandari, P.S. (1972) Impact Noise Rating of Resilient Floors. Acustica, 26, pp. 135-139.

64. Clark, D.M. (1970) Subjective Study of the Sound Transmission Class System for Rating Building Partitions. J. Acoust. Soc. Am., 47, pp. 676-682.

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