1、BSI Standards PublicationBS ISO 1999:2013Acoustics Estimation ofnoise-induced hearing lossBS ISO 1999:2013 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 1999:2013.The UK participation in its preparation was entrusted to TechnicalCommittee EH/1/1, Hearing.A li
2、st of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLim
3、ited 2013ISBN 978 0 580 70888 6ICS 13.140Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 October 2013.Amendments issued since publicationDate Text affectedBS IS
4、O 1999:2013 ISO 2013Acoustics Estimation of noise-induced hearing lossAcoustique Estimation de la perte auditive induite par le bruitINTERNATIONAL STANDARDISO1999Third edition2013-10-01Reference numberISO 1999:2013(E)BS ISO 1999:2013ISO 1999:2013(E)ii ISO 2013 All rights reservedCOPYRIGHT PROTECTED
5、DOCUMENT ISO 2013All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission
6、 can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 1999:2013ISO 1999:2013(E) IS
7、O 2013 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 24 Principle 35 Description and measurement of noise exposure . 36 Prediction of the effects of noise on hearing threshold . 46.1 Statistical distribution of hearing thres
8、hold levels of a noise-exposed population 46.2 Databases for hearing threshold levels associated with age (HTLA) 46.3 Calculation of noise-induced permanent threshold shift, N .57 Assessment of noise-induced hearing loss and disability . 87.1 Hearing loss . 87.2 Hearing disability . 87.3 Risk of hea
9、ring disability 8Annex A (informative) Calculation of database A, statistical distribution of hearing thresholds as a function of age (HTLA) for an otologically normal population (highly screened) 10Annex B (informative) Examples for database B 13Annex C (informative) Example of assessment of risk o
10、f noise-induced hearing loss and disability .17Annex D (informative) Tables with examples for NIPTS data 20Bibliography .22BS ISO 1999:2013ISO 1999:2013(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The
11、work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-gover
12、nmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in
13、the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directivesAttention is drawn to the possibili
14、ty that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of pat
15、ent declarations received. www.iso.org/patentsAny trade name used in this document is information given for the convenience of users and does not constitute an endorsement.The committee responsible for this document is ISO/TC 43, Acoustics.This third edition cancels and replaces the second edition (
16、ISO 1999:1990), of which it constitutes a minor revision.iv ISO 2013 All rights reservedBS ISO 1999:2013ISO 1999:2013(E)IntroductionThis International Standard presents, in statistical terms, the relationship between noise exposures and the “noise-induced permanent threshold shift” (NIPTS) in people
17、 of various ages. It provides procedures for estimating the hearing loss due to noise exposure of populations free from auditory impairment other than that due to noise (with allowance for the effects of age) or of unscreened populations whose hearing capability has been measured or estimated. NIPTS
18、 is treated here as an additive term independent of other components of hearing threshold levels. For any given noise exposure, it has a range of positive values representing the variability of noise-damage susceptibility between individuals of a population.Persons regularly exposed to noise can dev
19、elop hearing loss of varying severity. Due to this hearing loss, their understanding of speech, perception of everyday acoustic signals, or appreciation of music may be impaired. With the exception of exposure to blast, high-impulse noise and extremely high levels of steady noise, permanent impairme
20、nt of the hearing organ takes time and is progressive over months, years, or decades of exposure. NIPTS is usually preceded by a reversible temporary effect on hearing called noise-induced “temporary threshold shift” (TTS). The severity of TTS and recovery from it depend upon exposure level and dura
21、tion. For a single individual, it is not possible to determine precisely which changes in hearing threshold level are caused by noise and which changes are caused by other factors, although, in doubtful individual cases, the data in this International Standard might provide an additional means for e
22、stimating the most probable causes in audiological diagnosis. However, for a large population exposed to a specific noise, changes in the statistical distributions of hearing threshold levels can be determined. Parameters, such as the mean NIPTS and the median NIPTS, can be used to describe differen
23、ces in hearing threshold levels between two populations that are similar in all relevant respects except that one population has had a well-defined (usually occupational) noise exposure. Throughout this International Standard, the term NIPTS is applied to changes in the noise-induced permanent thres
24、hold shift of statistical distributions of groups of people; it is not to be applied to individuals.This International Standard can be applied to the calculation of the risk of sustaining hearing loss due to regular occupational noise exposure or due to any daily repeated noise exposure. In some cou
25、ntries, hearing loss caused by occupational noise exposure can have legal consequences with respect to responsibility and compensation. The hearing threshold level at the various frequencies, at which a hearing impairment is deemed to exist (fence), depends not only on the hearing loss per se, but f
26、requently on legal definitions and interpretations based on social and economic considerations. In addition, the definition of a hearing impairment depends on the quality of speech recognition desired, the average level of background noise, and with respect to the relative importance of the various
27、frequencies, perhaps even on the language. Consequently, this International Standard does not stipulate (in contrast to the first edition of ISO 1999) a specific formula for assessment of the risk of impairment, but specifies uniform methods for the prediction of hearing loss, which can be used for
28、the assessment of impairment according to the formula desired or stipulated in a specific country. The results obtained by this International Standard may also be used for estimating the permanent effects of noise on the perception of everyday acoustic signals, the appreciation of music, or the effe
29、ct of one specific frequency not necessarily stipulated by a hearing impairment formula.Since noise-induced hearing loss is the result not only of occupational noise exposure but also of the total noise exposure of the population, it may be important to take the non-occupational exposure of individu
30、als (during commuting to and from their jobs, at home, and during recreational activities) into account. Only if this non-occupational exposure is negligible compared with the occupational exposure does this International Standard allow prediction of the occurrence of hearing loss due to occupationa
31、l noise exposure. Otherwise, it should be used to calculate the hearing loss to be expected from the combined (occupational plus non-occupational) total daily noise exposure. The contribution of the occupational noise exposure to the total hearing loss can then be estimated, if desired.The selection
32、 of maximum tolerable or maximum permissible noise exposures and protection requirements, as well as the selection of specific formulae for impairment risk assessment or compensation purposes, require consideration of ethical, social, economic, and political factors not amenable to international sta
33、ndardization. Individual countries differ in their interpretation of these factors and these factors are therefore considered outside the scope of this International Standard. ISO 2013 All rights reserved vBS ISO 1999:2013ISO 1999:2013(E)For reasons given above, this International Standard, by itsel
34、f, does not comprise a complete guide for risk assessment and protection requirements, and for practical use, it has to be complemented by national standards or codes of practice delineating the factors which are here left open.vi ISO 2013 All rights reservedBS ISO 1999:2013INTERNATIONAL STANDARD IS
35、O 1999:2013(E)Acoustics Estimation of noise-induced hearing loss1 ScopeThis International Standard specifies a method for calculating the expected noise-induced permanent threshold shift in the hearing threshold levels of adult populations due to various levels and durations of noise exposure; it pr
36、ovides the basis for calculating hearing disability according to various formulae when the hearing threshold levels at commonly measured audiometric frequencies, or combinations of such frequencies, exceed a certain value.NOTE 1 This International Standard does not specify frequencies, frequency com
37、binations, or weighted combinations to be used for the evaluation of hearing disability; nor does it specify a hearing threshold level (fence) which it is necessary to exceed for hearing disability to exist. Quantitative selection of these parameters is left to the user. All sound pressure levels st
38、ated in this International Standard do not consider the effect of hearing protectors which would reduce effective exposure levels and modify the spectrum at the ear.The measure of exposure to noise for a population at risk is the noise exposure level normalized to a nominal 8 h working day, LEX,8h,
39、for a given number of years of exposure. This International Standard applies to noise at frequencies less than approximately 10 kHz which is steady, intermittent, fluctuating, irregular. Use of this International Standard for sound pressures exceeding 200 Pa (140 dB relative to 20 Pa) is recognized
40、as extrapolation.Formulae are presented to calculate the hearing loss, including statistical distribution, at a range of audiometric frequencies due to exposure to noise as a function of level of noise exposure and duration of exposure (in years). The formulae do not distinguish between male and fem
41、ale populations.NOTE 2 Although the models of hearing loss are based on data assumed to stem primarily from populations exposed to occupational noise, they may be used, with some caution, for estimating the effects of comparable non-occupational and combined exposures.NOTE 3 The prediction method pr
42、esented is based primarily on data collected with essentially broadband, steady, non-tonal noise.To calculate hearing threshold levels and the risk of acquiring hearing loss due to noise exposure, it is necessary to make use of a comparable population. This International Standard contains a definiti
43、on of a highly screened otologically normal population (in accordance with ISO 7029) and three examples of unscreened populations of three typical industrialized societies. The users of this International Standard may choose a comparable population according to their particular requirements.NOTE 4 A
44、ll data and procedures presented in this International Standard are based on deliberate simplifications of experimental data where the daily sound exposure duration did not exceed 12 h. The resulting approximations restrict the validity to the stated ranges of the variables, percentages, sound expos
45、ure levels, and frequency ranges.This International Standard is based on statistical data and therefore cannot be applied to the prediction or assessment of the hearing loss of individual persons except in terms of statistical probabilities.2 Normative referencesThe following documents, in whole or
46、in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 7029, Acoustics Statistical distribution
47、of hearing thresholds as a function of ageISO 9612, Acoustics Determination of occupational noise exposure Engineering methodISO/TR 25417, Acoustics Definitions of basic quantities and terms ISO 2013 All rights reserved 1BS ISO 1999:2013ISO 1999:2013(E)3 Terms and definitionsFor the purposes of this
48、 document, the terms and definitions in ISO/TR 25417 and the following apply.3.1A-weighted noise exposure level normalized to a nominal 8 h working dayLEX,8hlevel, in decibels, given by the formulaLL TTpTEX hAeq eelg dB,/8010=+() whereLpAeq,Teis the A-weighted equivalent continuous sound pressure le
49、vel for Te;Teis the effective duration of the working day in hours;T0is the reference duration (T0= 8 h).Note 1 to entry: The quantity “noise exposure level normalized to a nominal 8 h working day” may also be called “daily noise exposure level”.Note 2 to entry: If the exposure averaged over n days is desired, for example if noise exposure levels normalized to a nominal 8 h working day for weekly exposures are considered, the average value of LEX,8h, in decibels, over the whole period may be determined from the values of (LEX,8h)ifor each day usi
