1、 ANSI/ASA S12.71-2018 AMERICAN NATIONAL STANDARD Performance Criteria for Systems that Estimate the Attenuation of Passive Hearing Protectors for Individual Users Accredited Standards Committee S12, Noise Standards Secretariat Acoustical Society of America 1305 Walt Whitman Road, Suite 300 Melville,
2、 NY 11747 ANSI/ASAS12.71-2018 The American National Standards Institute, Inc. (ANSI) is the national coordinator of voluntary standards development and the clearinghouse in the U.S.A. for information on national and international standards. The Acoustical Society of America (ASA) is an organization
3、of scientists and engineers formed in 1929 to increase and diffuse the knowledge of acoustics and to promote its practical applications. ANSI/ASA S12.71-2018 AMERICAN NATIONAL STANDARD Performance Criteria for Systems that Estimate the Attenuation of Passive Hearing Protectors for Individual Users S
4、ecretariat: Acoustical Society of America Approved on May 7, 2018 by: American National Standards Institute, Inc. Abstract This standard pertains to systems intended to estimate the attenuation of hearing protection devices (HPDs) obtained by individual wearers in actual practice. Such systems are d
5、esignated field attenuation estimation systems (FAESs). This standard provides a classification of FAESs and specifies performance criteria. It also details the evaluation methodology and statistical calculations to be performed on such systems in order to state the uncertainty associated with the i
6、ndividual attenuation estimates that they provide, and specifies a method for computing a personal attenuation rating (PAR). FAES-derived data do not replace the attenuation values from ANSI/ASA S12.6 or the insertion-loss data from ANSI/ASA S12.42, nor are such data suitable for labeling the attenu
7、ation of HPDs. AMERICAN NATIONAL STANDARDS ON NOISE The Acoustical Society of America (ASA) provides the Secretariat for Accredited Standards Committees S1 on Acoustics, S2 on Mechanical Vibration and Shock, S3 on Bioacoustics, S3/SC 1 on Animal Bioacoustics, and S12 on Noise. These committees have
8、wide representation from the technical community (manufacturers, consumers, trade associations, organizations with a general interest, and government representatives). The standards are published by the Acoustical Society of America as American National Standards after approval by their respective S
9、tandards Committees and the American National Standards Institute (ANSI). These standards are developed and published as a public service to provide standards useful to the public, industry, and consumers, and to Federal, State, and local governments. Each of the Accredited Standards Committees (ope
10、rating in accordance with procedures approved by ANSI) is responsible for developing, voting upon, and maintaining or revising its own Standards. The ASA Standards Secretariat administers Committee organization and activity and provides liaison between the Accredited Standards Committees and ANSI. A
11、fter the Standards have been produced and adopted by the Accredited Standards Committees, and approved as American National Standards by ANSI, the ASA Standards Secretariat arranges for their publication and distribution. An American National Standard implies a consensus of those substantially conce
12、rned with its scope and provisions. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity.
13、 Consensus requires that all views and objections be considered and that a concerted effort be made towards their resolution. The use of an American National Standard is completely voluntary. Their existence does not in any respect preclude anyone, whether he or she has approved the Standards or not
14、, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the Standards. NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken periodic
15、ally to reaffirm, revise, or withdraw this Standard. Acoustical Society of America Standards Secretariat 1305 Walt Whitman Road, Suite 300 Melville, New York 11747 Telephone: 1 (631) 390-0215 Fax: 1 (631) 923-2875 E-mail: asastdsacousticalsociety.org 2018 by Acoustical Society of America. This stand
16、ard may not be reproduced in whole or in part in any form for sale, promotion, or any commercial purpose, or any purpose not falling within the provisions of the U.S. Copyright Act of 1976, without prior written permission of the publisher. For permission, address a request to the Standards Secretar
17、iat of the Acoustical Society of America. Acoustical Society of America 2018 All rights reserved iContents 1 Scope . 1 2 Normative references . 1 3 Terms and definitions . 2 4 Types of field attenuation estimation systems . 3 5 Performance characteristics for FAESs that report a PAR 4 5.1 Verificati
18、on and calibration 4 5.2 Maximum permissible ambient noise levels (MPANLs) 4 5.3 Maximum test signal exposure levels 5 5.4 Assessment of bias and nonlinearity . 6 5.5 Maximum and minimum measurable attenuation values 6 6 Performance characteristics for FAESs that report only pass/fail indicators . 6
19、 6.1 Verification and calibration 6 6.2 Maximum permissible ambient noise levels (MPANLs) 6 6.3 Maximum test signal exposure levels 7 6.4 Measurement uncertainty for systems that report only pass/fail results . 7 7 Computation of A-weighted attenuation, REATA and FAESA 8 7.1 REATA 8 7.2 FAESA 9 8 Co
20、mputation of PAR and its associated uncertainty . 9 8.1 PARx 10 8.2 Computation of the principal sources of uncertainty . 10 9 Experimental data collection for specification of system performance 12 9.1 Procedure for FAESs using standard HPDs . 12 9.2 Procedure for FAESs using surrogate HPDs 13 9.3
21、Procedure for FAESs that report only pass/fail results . 15 10 Surrogate error for FAESs using surrogate HPDs . 15 10.1 Computation of surrogate error . 15 10.2 Statistical test for the surrogate error 15 11 Information to be included in user instructions for FAESs . 16 Annex A (normative) FAES perf
22、ormance statement . 17 Annex B (informative) Equivalence testing to determine MPANLs . 19 Annex C (informative) Example assessment of bias and nonlinearity 21 Acoustical Society of America 2018 All rights reserved iiAnnex D (informative) Example graphical computation of minimum and maximum attenuati
23、on values 22 Annex E (informative) Example of the computation of measurement uncertainty for a pass/fail FAES . 24 Annex F (informative) Example of the computation of composite PAR 27 F.1 Computation including audiometric data . 27 F.2 Computation in absence of audiometric data 27 F.3 Simplified com
24、putation based on lowest-ear PAR 28 Annex G (informative) Example of the computation of PAR and its associated uncertainty 29 G.1 Computation of PAR and its associated uncertainty . 29 G.2 Example cases to be used for validation of the computation of PAR and its associated uncertainty . 32 Annex H (
25、normative) Laboratory-determined values of fitting and spectrum uncertainty . 34 Bibliography 36 Figures Figure C.1 Bland-Altman scatter plot. Each point represents one measurement for a given fit of an HPD using both REAT and a FAES. 21 Figure D.1 Prediction error scatter plot for a physical FAES u
26、sed to establish the measurable attenuation range. Each point represents one measurement for a given fit of an HPD using both REAT and a FAES. 23 Figure E.1 Pass/fail FAES measurement data and fitted logistic regression function describing the measurement uncertainty. . 26 Figure F.1 Example of left
27、 and right attenuation as well as the resulting composite attenuation. . 28 Tables Table 1 Types of FAESs 4 Table 2 Octave-band values of the MPANLs corresponding to the lowest FAES test frequency, for earcups with an attenuation of 0 dB. 5 Table 3 Values of for various protection performance values
28、, x. 10 Table 4 Experimental procedure to collect data for FAESs that test standard HPDs . 13 Table 5 Experimental procedure to collect data for FAESs that test surrogate HPDs 14 Table A.1 Example performance statement for a FAES that reports a PAR . 17 Table A.2 Example performance statement for a
29、FAES that reports a pass/fail rating . 18 Table B.1 Illustrative data for a physical FAES. . 19 Acoustical Society of America 2018 All rights reserved iiiTable E.1 REATA (dB) and corresponding FAESB outputs for a pass/fail FAES, sorted by increasing values of REATA. The criterion level CRIT for thes
30、e data is 15.0 dB. Rows containing erroneous measurements are shaded (shading in one row appears inconsistent due to rounding). 24 Table H.1 Generic laboratory-determined values of fitting uncertainty (ufit), values in dB. 34 Table H.2 Generic laboratory-determined values of spectrum uncertainty (us
31、pectrum), values in dB . 35 Acoustical Society of America 2018 All rights reserved iv Foreword This Foreword is for information only and is not a part of the American National Standard ANSI/ASA S12.71-2018 American National Standard Performance Criteria for Systems that Estimate the Attenuation of P
32、assive Hearing Protectors for Individual Users. As such, this Foreword may contain material that has not been subjected to public review or a consensus process. In addition, it does not contain requirements necessary for conformance to the standard. This standard comprises a part of a group of defin
33、itions, standards, and specifications for use in noise. It was developed and approved by Accredited Standards Committee S12 Noise, under its approved operating procedures. Those procedures have been accredited by the American National Standards Institute (ANSI). The Scope of Accredited Standards Com
34、mittee S12 is as follows: Standards, specifications, and terminology in the field of acoustical noise pertaining to methods of measurement, evaluation, and control, including biological safety, tolerance, and comfort, and physical acoustics as related to environmental and occupational noise. This is
35、 a new American National Standard, and it is not comparable to any existing ISO Standard. At the time this Standard was submitted to Accredited Standards Committee S12, Noise, for approval, the membership was as follows: S.J. Lind, Chair D.F. Winker, Vice-Chair N.B. Stremmel, Secretary 3M Personal S
36、afety Division E.H. Berger Acoustical Society of America . R.D. Hellweg . D. Lubman (Alt.) Air-Conditioning, Heating and Refrigeration Institute S.J. Lind . L. Bulookbashi (Alt.) American Academy of Audiology T. Ricketts C. Schweitzer (Alt.) American Academy of Otolaryngology - Head and Neck Surgery
37、 R.A. Dobie A. Kim (Alt.) American Industrial Hygiene Association . D. Driscoll . M. Kram (Alt.) American Speech-Language-Hearing Association . L.A. Wilber . N. DiSarno (Alt.) Boeing Commercial Airplanes, Noise, Vibration and Emissions K. Lai . M. Kosanchick (Alt.) Caterpillar, Inc. . K.G. Meitl C.
38、Crowell (Alt.) Compressed Air and Gas Institute . R.C. Johnson . D.R. Bookshar (Alt.) Acoustical Society of America 2018 All rights reserved vCouncil for Accreditation in Occupational Hearing Conservation C. Moritz . C. Achutan (Alt.) Cummins, Inc. S. More Custom Protect Ear, Inc. J. Goldberg . A. B
39、obyrev (Alt.) Emerson Electric Copeland Corporation . A.T. Herfat . M. Strand (Alt.) Engineering Dynamics S. McGregor ESI Group . C. Musser . B. Gardner (Alt.) ETS Lindgren Acoustic Systems D.F. Winker . M. Black (Alt.) ExxonMobil B. Moulton . N. Hart (Alt.) G.R.A.S. Sound FAX: 631-923-2875; E-mail:
40、 asastdsacousticalsociety.org. Acoustical Society of America 2018 All rights reserved viii Introduction Background For many years a standard has existed for measuring the hearing protector attenuation achieved by groups of test subjects in a laboratory setting, the most recent embodiment of which is
41、 ANSI/ASA S12.6. Data from that method have been commonly used for rating and labeling the noise attenuation of hearing protection devices (HPDs). However, the laboratory method does not address a key question, namely, “What amount of protection can, or is, a given individual actually getting from h
42、is/her HPD?” To do so, manufacturers have developed a variety of field attenuation estimation systems (FAESs), colloquially referred to as “fit test systems,” that can be used for measurements at the workplace. What has been lacking is a national standard that provides guidance on standardizing impo
43、rtant performance aspects and data outputs from the various FAESs in order to facilitate selection of systems and application of the test results. FAESs generally provide data in terms of a single-number personal attenuation rating (PAR). A PAR is computed for one or more fits of the HPD by an indiv
44、idual in a manner similar to the computation of the hearing-protector manufacturers labeled attenuation values that are derived from laboratory test data for groups of subjects. Examples of labeled values are the Noise Reduction Rating (NRR) as required by the U.S. Environmental Protection Agency (1
45、979) and the Noise Level Reduction Statistic for use with A-weighting (NRSA) as specified in ANSI/ASA S12.68. Although the various FAESs have the same purpose and produce attenuation values that are presented in similar ways to one another, the underlying technology used to estimate attenuation and
46、compute PARs can differ dramatically. It can range from psychophysical tests to objective microphone measurements, and from systems that calculate PAR in a manner analogous to the NRSA as defined in ANSI/ASA S12.68, to others that simply indicate a pass/fail answer based on achieving a minimum requi
47、red attenuation value. The various types of FAESs are described and categorized in this standard. PARs are based on measurements at a single point in time and provide a more direct estimate of the protection that a given individual is expected to receive from her or his HPD than does average data fr
48、om a group of laboratory subjects. However, PARs are still not based upon in situ measurements for actual wearers and the exposures they experience during their work shifts. Thus, PARs reflect what a wearer can achieve and has been shown to achieve, not necessarily what s/he truly achieves on a day-
49、to-day basis. Applications for FAESs and the specification of uncertainty FAESs may be used to train the employee to better fit her or his HPD and also to train the trainer in that process. However, users may also wish to apply FAES results together with an organizations noise-exposure policies to estimate whether a worker is obtaining adequate protection from existing HPDs, or to assign HPDs based upon noise exposures. Though some FAESs currently exist that can estimate the attenuation provided by earmuffs, the usual focus o
