1、 ANSI S3.21-2004AMERICAN NATIONAL STANDARDMethods for Manual Pure-Tone Threshold AudiometryAccredited Standards Committee S3, BioacousticsStandards SecretariatAcoustical Society of America35 Pinelawn Road, Suite 114 EMelville, NY 11747-3177ANSI S3.21-2004Reaffirmed by ANSI April 16, 2009 The America
2、n 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 of scientists and engineers formed in 192
3、9 to increase and diffuse the knowledge of acoustics and to promote its practical applications. ANSI S3.21- 2004 (Revision of ANSI S3.21-1978) AMERICAN NATIONAL STANDARD Methods for Manual Pure-Tone Threshold Audiometry Secretariat Acoustical Society of America Approval date: April 8, 2004 American
4、National Standards Institute, Inc. Abstract This Standard is a revision of the American National Standard ANSI S3.21-1978 Methods for Manual Pure-Tone Threshold Audiometry. This Standard provides a procedure for pure-tone audiometry that will serve the needs of persons conducting threshold measureme
5、nts in industry, schools, medical settings, and other areas where valid audiometric threshold measurements are needed. AMERICAN NATIONAL STANDARDS ON ACOUSTICS The Acoustical Society of America (ASA) provides the Secretariat for Accredited Standards Committees S1 on Acoustics, S2 on Mechanical Vibra
6、tion and Shock, S3 on Bioacoustics, and S12 on Noise. These committees have wide representation from the technical community (manufacturers, consumers, trade associations, general interest, and government representatives). The standards are published by the Acoustical Society of America as American
7、National Standards after approval by their respective Standards Committees and the American National Standards Institute. 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.
8、Each of the accredited Standards Committees, operating in accordance with procedures approved by American National Standards Institute (ANSI), is responsible for developing, voting upon, and maintaining or revising its own Standards. The ASA Standards Secretariat administers Committee organization a
9、nd activity and provides liaison between the Accredited Standards Committees and ANSI. After 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 dist
10、ribution. An American National Standard implies a consensus of those substantially concerned 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. Subs
11、tantial agreement means much more than a simple majority, but not necessarily unanimity. 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
12、 not in any respect preclude anyone, whether he or she has approved the Standards or not, 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 proce
13、dures of the American National Standards Institute require that action be taken periodically to reaffirm, revise, or withdraw this Standard. Acoustical Society of America ASA Secretariat 35 Pinelawn Road, Suite 114E Melville, New York 11747-3177 Telephone: 1 (631) 390-0215 Fax: 1 (631) 390-0217 E-ma
14、il: asastdsaip.org 2004 by Acoustical Society of America. This standard 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 Copyright Act of 1976, without prior written permission of the publish
15、er. For permission, address a request to the Standards Secretariat of the Acoustical Society of America.i Contents 1 Scope .1 1.1 Purpose of standard 1 1.2 Limit of standard1 1.3 Modifications of standard procedures 1 1.4 Source1 2 Normative References 1 3 Definitions .2 4 General Requirements .4 4.
16、1 Ear canal 4 4.2 Earphone placement 4 4.3 Instructions .4 4.4 Response task 4 4.5 Interpretation of response 4 4.5.1 On response and off response.5 4.5.2 Latency of response5 4.5.3 False responses .5 5 Determination of threshold 5 5.1 Familiarization procedure.5 5.2 Determination of threshold .5 5.
17、2.1 Tone duration .5 5.2.2 Interval between tones 5 5.2.3 Level of first presentation 6 5.2.4 Levels of succeeding presentations6 5.2.5 Threshold of hearing .6 6 Standard Procedures for Air-Conduction Measures 6 6.1 Test environment .6 6.2 Instrumentation and calibration .6 6.3 Frequency.6 6.4 Order
18、 6 6.5 Masking in air-conduction audiometry .6 6.6 Recording of result 7 6.6.1 Audiogram form 7 6.6.2 Audiogram Symbols7 6.6.3 Other information 7 ii 7 Standard Procedures for Bone-Conduction Measures in Diagnostic Audiometry 7 7.1 Instrumentation .7 7.2 Calibration 7 7.3 Vibrator placement 7 7.4 Co
19、vering of ear7 7.5 Frequencies 8 7.6 Order 8 7.7 Masking 8 7.8 Recording of results.8 Annex A .9 A.1 Air-conduction symbols 9 A.2 Bone-conduction symbols 9 A.3 Symbols representation .9 A.4 Multiple notation 9 A.5 No response .9 A.6 Separate forms10 A.7 Lines connecting symbols 10 A.8 Color coding10
20、 Annex B .12 B.1 General information .12 Figures Figure A.1 Recommended form of audiogram and audiogram symbols11 iii Foreword This foreword is for information only and is not an integral part of ANSI S3.21-2004 American National Standard Methods for Manual Pure-Tone Threshold Audiometry. This Ameri
21、can National Standard was developed and approved by Accredited Standards Committee S3, under operating procedures approved by the American National Standards Institute (ANSI). Accredited Standards Committee S3, Bioacoustics has the following scope: Standards, specifications, methods of measurement a
22、nd test, and terminology in the fields of psychological and physiological acoustics, including aspects of general acoustics, shock, and vibration which pertain to biological safety, tolerance and comfort. This second edition replaces ANSI S3.21-1978 American National Standard Methods for Manual Pure
23、-Tone Threshold Audiometry. It has been revised to include current standard references which appear in the text and other types of earphones (insert and circumaural) to be used to elevate collapsing ear canals (see clause 4.1 note). All other changes are purely formative or editorial and do not chan
24、ge the technical intent of this standard. This American National Standard presents procedures for accomplishing manual hearing-threshold measurement with pure tones that are applicable in a wide variety of settings. Although the standard has been written to aid in the accomplishment of a measurement
25、, it is appropriate to point out that it differs from other measurement techniques in that it deals with human behavior. Rigid adherence to the procedure in every circumstance will not necessarily produce effective results. See Clause 1.3 for more detail. iv At the time this Standard was submitted t
26、o Accredited Standards Committee S3, Bioacoustics, for final approval, the membership was as follows: R.F. Burkard, Chair C.A. Champlin, Vice Chair S. Blaeser, Secretary Acoustical Society of America R.F. Burkard C.A. Champlin (Alt.) American Academy of Audiology .L. Shotland D.A. Fabry (Alt.) Ameri
27、can Academy of Otolaryngology, Head and Neck Surgery, Inc. .R.A. Dobie . L.A. Michael (Alt.) American Industrial Hygiene Association J. Banach . D. Driscoll (Alt.) American Speech-Hearing-Language Association (ASHA) . G. Linn R. Levinson (Alt.) Audio Engineering Society, Inc. . R.H. Campbell M.R. Ch
28、ial (Alt.) Caterpillar, Inc. . D. Roley . K.G. Meitl (Alt.) Chase Ergonomics, Inc. . G. Shumate D. Chase (Alt.) Council for Accreditation in Occupational Hearing Conservation (CAOHC) R.D. Bruce E.H. Berger (Alt.) Hearing Industries Association T.A. Victorian . C.M. Rogin (Alt.) Howard Leight Industr
29、ies . V. Larson .E. Woo (Alt.) International Hearing Society . . K. LaFerle John Deere L. DeVries National Institute of Standards and Technology .V. Nedzelnitsky R. Wagner (Alt.) Power Tool Institute . VACANT J. Nosko (Alt.) v U.S. Army Aeromedical Research Lab . W. Ahroon N. Alem (Alt.) U.S. Army C
30、ERL . L. Pater . D. Delaney (Alt.) U.S. Army Human Research FAX: +1 631-390-0217. E-mail: asastdsaip.org S. Benson T. Frank R. Veillette J. Foreman R. Grason L. Wilber S. Fournier T. Letowski AMERICAN NATIONAL STANDARD ANSI S3.21-2004 1 American National Standard Methods for Manual Pure-Tone Thresho
31、ld Audiometry 1 Scope 1.1 Purpose of standard Pure-tone threshold audiometry is the procedure used in the assessment of an individuals threshold of hearing for pure tones. Pure-tone threshold audiometry includes manual air-conduction measurements at octave intervals from 250 through 8000 Hz and at i
32、ntermediate frequencies as needed. When abrupt differences of 20 dB or more occur between adjacent octave frequencies, additional frequencies may be included at the discretion of the tester. Bone-conduction measurements may be carried out if indicated by the test requirements at octave intervals fro
33、m 250 through 4000 Hz. Also, when required, masking is to be used. The purpose of this standard is to present procedures for conducting manual pure-tone threshold audiometry whose use will minimize intertest differences based on test method. 1.2 Limit of standard This standard is limited to a descri
34、ption of the measurement method of manual pure-tone threshold audiometry. Hearing screening techniques are outside its purview. 1.3 Modifications of standard procedures The procedures described in this standard are usable in a wide variety of circumstances. However, certain individuals, such as youn
35、g children, developmentally delayed persons, uncooperative persons, or neurologically handicapped persons may require modifications of the procedures. In any instance where response behavior is apt to veer from the usual, the procedure should be modified; however, the modification shall be readily i
36、dentified and specified by the user, the modifications shall be noted in the reporting of results. Another kind of modification is exemplified as follows: The user of the standard who functions in a work setting which requires monitoring audiometry or diagnostic audiometry will use instrumentation w
37、hich pertains to that particular setting and the frequencies at which threshold is measured will be dictated by that situation. The choice of frequencies will depend on the purpose for which the procedure is being used. 1.4 Source The procedures detailed in this standard are adapted from those descr
38、ibed in the Draft Guidelines for Manual Pure-Tone Audiometry (Wilson et al. 1974) and the Guidelines for a Training Program for Audiometric Technicians (NASNRC, 1973). 2 Normative References The following Standards contain provisions which, through reference in this text, constitute provisions of th
39、is American National Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this American National Standard are encouraged to investigate the possibility of applying the most recent editions of the standards
40、indicated below. ANSI S3.21-2004 2 ANSI S3.1-1999 (R 2003), American National Standard Maximum Permissible Ambient Noise Levels for Audiometric Test Rooms ANSI S3.6-1996, American National Standard Specification for Audiometers ANSI S3.13-1987 (R 2002), American National Standard Mechanical Coupler
41、for Measurement of Bone Vibrators ANSI S3.20-1995 (R 2003), American National Standard Bioacoustical Terminology 3 Definitions For the purpose of this Standard, the definitions given in ANSI S3.20-1995 and the following apply. Note: All Definitions are technically equivalent to ANSI S3.20-1995 altho
42、ugh some have editorial differences and been expanded for the user of this standard. 3.1 air conduction. Transmission of sound through the outer and middle ear to the inner ear. 3.2 bone conduction. Transmission of sound to the inner ear primarily by means of mechanical vibration of the cranial bone
43、s. 3.3 threshold of hearing. For a specified signal, the minimum average (time-mean-square) sound pressure level that is capable of evoking an auditory sensation in a specified fraction of trials. The characteristics of the signal, the manner in which the signal is presented to the subject, and the
44、point at which the sound pressure level is measured should be specified. 3.4 reference equivalent threshold sound pressure level. At a specified frequency, the mean/modal value of the equivalent threshold sound pressure levels of a sufficiently large number of ears of otologically normal persons of
45、both sexes aged between 10 and 30 years inclusive, expressing the threshold of hearing in a specified acoustical coupler or artificial ear for a specified type of earphone. Abbreviation, RETSPL; unit decibel (dB). NOTE The values for air conduction of reference equivalent threshold sound pressure le
46、vels are specified in ANSI S3.6 1996 American National Standard Specification for Audiometers. 3.5 reference equivalent threshold force level. At a specified frequency, the mean value of the equivalent force levels, in decibels relative to 1N, derived from a sufficiently large number or ears of otol
47、ogically normal persons of both sexes aged between 18 and 30 years, inclusive, expressing the threshold of hearing in a specified mechanical coupler for a specified configuration of bone vibrator. Abbreviation, RETFL; unit decibel (dB), symbol LF Note The values for bone conduction of reference equi
48、valent threshold force level (RETFL) are specified in ANSI S3.6 1996 American National Standard Specification for Audiometers. 3.6 otologically normal subject. Person in a normal state of health who is free from all signs or symptoms of ear disease and from excessive wax in the ear canal, which woul
49、d block incoming sound and has no history of undue exposure to noise. ANSI S3.21-2004 3 3.7 hearing level for pure tones. Hearing threshold of a given ear at a specified frequency and for a specified type of transducer when measured with an audiometer calibrated to reference equivalent threshold levels for air or bone conduction. The ETSPL or ETFL minus the appropriate RETSPL or RETFL. Abbreviation HL. 3.8 occlusion effect. Increase in loudness of bone-conducted signals, usually at frequencies below 2000 Hz when the external ear(s) are covered. Typically observed
