ASA S3 55 PART 3-2015 AMERICAN NATIONAL STANDARD Electroacoustics C Simulators of Human Head and Ear C Part 3 Acoustic Coupler for the Calibration of Supra-aural Earphones Used in .pdf

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1、 ANSI/ASA S3.55-2015/Part 3 / IEC 60318-3:2014 AMERICAN NATIONAL STANDARD Electroacoustics Simulators of Human Head and Ear Part 3: Acoustic Coupler for the Calibration of Supra-aural Earphones Used in Audiometry (a nationally adopted international standard) Accredited Standards Committee S3, Bioaco

2、ustics Standards Secretariat Acoustical Society of America 1305 Walt Whitman Road, Suite 300 Melville, NY 11747ANSI/ASAS3.55-2015/Part 3 /IEC60318-3 :2014 The American National Standards Institute, Inc. (ANSI) is the national coordinator of voluntary standards development and the clearinghouse in th

3、e 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 1929 to increase and diffuse the knowledge of acoustics and to promote its practical applications. ANSI/ASA S3.55-2015/Part 3 / IEC 60318

4、-3:2014 AMERICAN NATIONAL STANDARD Electroacoustics Simulators of Human Head and Ear Part 3: Acoustic Coupler for the Calibration of Supra-aural Earphones Used in Audiometry (a nationally adopted international standard) Secretariat: Acoustical Society of America Approved on May 15, 2015 by: American

5、 National Standards Institute, Inc. Abstract This standard specifies an acoustic coupler for objective and reproducible measurements of supra-aural audiometric earphones in the frequency range from 125 Hz to 8000 Hz. The results of these measurements can be used for specifying reference equivalent t

6、hreshold sound pressure levels (RETSPL) for the calibration of audiometers. AMERICAN NATIONAL STANDARDS ON BIOACOUSTICS 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/S

7、C 1 on Animal Bioacoustics, and S12 on Noise. These committees have 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

8、 as American National Standards after approval by their respective Standards 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

9、 local governments. Each of the Accredited Standards Committees (operating 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 prov

10、ides 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 distribution. An America

11、n 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. Substantial agreement me

12、ans 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 not in any respect

13、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 procedures of the America

14、n National Standards Institute require that action be taken periodically to reaffirm, revise, or withdraw this Standard. Acoustical Society of America ASA Secretariat 1305 Walt Whitman Road, Suite 300 Melville, New York 11747 Telephone: 1 (631) 390-0215 Fax: 1 631-923-2875 E-mail: asastdsacousticals

15、ociety.org 2015 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 U.S. Copyright Act of 1976, without prior written permission of the publisher.

16、 For permission, address a request to the Standards Secretariat of the Acoustical Society of America. 2015 Acoustical Society of America All rights reserved iContents 1 Scope 1 2 Normative references 1 3 Terms and definitions 1 4 Construction 1 4.1 General 1 4.2 Cavity dimensions 2 4.3 Static pressu

17、re equalization . 4 4.4 Calibrated pressure type microphone 4 5 Coupling of earphone to acoustic coupler. 5 6 Calibration . 6 6.1 Reference environmental conditions 6 6.2 Method of calibration 6 Figures Figure 1 Dimensions of acoustic coupler . 3 Figure 2 Coupling of earphone to coupler 5 Tables Tab

18、le 1 Height of the coupler as a function of the acoustic volume of the microphone 4 Table 2 Values of maximum permitted uncertainties Umax for a level of confidence of approximately 95 % . 7 2015 Acoustical Society of America All rights reserved ii Foreword This Foreword is for information only, and

19、 is not a part of the American National Standard ANSI/ASA S3.55-2015/Part 3 / IEC 60318-3:2014 American National Standard Electroacoustics Simulators of Human Head and Ear Part 3: Acoustic Coupler for the Calibration of Supra-aural Earphones Used in Audiometry. As such, this Foreword may contain mat

20、erial 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 definitions, standards, and specifications for use in bioacoustics. It was developed and ap

21、proved by Accredited Standards Committee S3 Bioacoustics, under its approved operating procedures. Those procedures have been accredited by the American National Standards Institute (ANSI). The Scope of Accredited Standards Committee S3 is as follows: Standards, specifications, methods of measuremen

22、t and test, and terminology in the fields of psychological and physiological acoustics, including aspects of general acoustics which pertain to biological safety, tolerance and comfort. This standard is a nationally adopted international standard (NAIS). It was undertaken as part of the revision of

23、ANSI/ASA S3.7-1995 (R2008), Method for Coupler Calibration of Earphones, which, in addition to coupler calibration methods, contains detailed information about the audiometric ear, the 6cc coupler, and the 2cc coupler. Several years ago, IEC 60318 was reorganized into several parts, which now includ

24、e the same information about the aforementioned couplers (IEC 60318, Parts 1, 3, and 5, respectively). Given that the manufacture of these couplers has changed little if at all in more than 25 years, the fact that the IEC and ANSI/ASA specifications for these couplers are essentially identical, and

25、the fact that manufacturers of these couplers do not produce different versions of the devices to meet alternative versions of the standards, harmonization was deemed appropriate. The first step in this process has been the move of the detailed coupler specifications from the previous version of ANS

26、I/ASA S3.7 to NAIS ANSI/ASA S3.55, Parts 1, 3, and 5, which correspond directly to their IEC 60318 counterparts. References in other standards that previously pointed to ANSI/ASA S3.7 for a particular coupler will now point to the appropriate NAIS ANSI/ASA S3.55 part instead as these documents are r

27、evised and updated. The next revision of ANSI/ASA S3.7 will focus solely on the calibration methods for earphones, and will also point to the appropriate NAIS ANSI/ASA S3.55 part, where the detailed coupler information now resides. This standard is an identical national adoption of IEC 60318-3 Ed. 2

28、.0 b:2014 Electroacoustics Simulators of human head and ear Part 3: Acoustic coupler for the calibration of supra-aural earphones used in audiometry, which was prepared by IEC/TC 29. However, in conformance with ANSI and IEC rules, the words “this part of ANSI/ASA S3.55 / IEC 60318” replace the word

29、s “this part of IEC 60318” where they appear in the IEC document, decimal points were substituted in place of the decimal commas used in IEC documents, and American English spelling is used in place of British English spelling. At the time this Standard was submitted to Accredited Standards Committe

30、e S3, Bioacoustics for approval, the membership was as follows: C.J. Struck, Chair P.B. Nelson, Vice-Chair S.B. Blaeser, Secretary Acoustical Society of America . C.J. Struck P.B. Nelson (Alt.) American Academy of Audiology . .C. Schweitzer T. Ricketts (Alt.) 2015 Acoustical Society of America All r

31、ights reserved iiiAmerican Academy of Otolaryngology, Head and Neck Surgery, Inc. .R.A. Dobie A. Kim (Alt.) American Industrial Hygiene Association . T.K. Madison D. Driscoll (Alt.) American Speech-Language-Hearing Association (ASHA) . L.A. Wilber . N. DiSarno (Alt.) Beltone/GN Resound S. Petrovic C

32、ouncil for Accreditation in Occupational Hearing Conservation (CAOHC) . L.D. Hager Diagnostic Group . T. McColley P. Dobrowski (Alt.) ETS Lindgren Acoustic Systems . S. Dunlap . D. Winker (Alt.) Etymotic Research, Inc. M.C. Killion . J.K. Stewart (Alt.) Food and Drug Administration S-C Peng G.R.A.S.

33、 Sound FAX: 631-923-2875; E-mail: asastdsacousticalsociety.org. AMERICAN NATIONAL STANDARD ANSI/ASA S3.55-2015/Part 3 / IEC 60318-3:2014 2015 Acoustical Society of America All rights reserved 1American National Standard Electroacoustics Simulators of Human Head and Ear Part 3: Acoustic Coupler for t

34、he Calibration of Supra-aural Earphones Used in Audiometry 1 Scope This part of ANSI/ASA S3.55 / IEC 60318 specifies an acoustic coupler for the measurement of supra-aural audiometric earphones in the frequency range from 125 Hz to 8,000 Hz. The sound pressure developed by an earphone is not, in gen

35、eral, the same in the coupler as in a persons ear. However, the acoustic coupler can be used as an objective and reproducible means of measuring the output of supra-aural earphones. It can be used for specifying reference equivalent threshold sound pressure levels (RETSPL) for the calibration of aud

36、iometers. 2 Normative references The following documents, in whole or 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

37、 any amendments) applies. IEC 61094-1, Measurement microphones Part 1: Specifications for laboratory standard microphones ISO/IEC Guide 98-3, Uncertainty of measurement Part 3: Guide to the expression of uncertainty in measurement (GUM:1995) 3 Terms and definitions For the purpose of this document,

38、the following definition applies: 3.1 acoustic coupler device for measuring the acoustic output of sound sources where the sound pressure is measured by a calibrated microphone coupled to the source by a cavity of predetermined shape and volume which does not necessarily approximate the acoustical i

39、mpedance of the normal human ear 4 Construction 4.1 General The coupler consists essentially of a cylindrical cavity whose acoustic transfer impedance is determined by the volume of air in the cavity and its dimensions (see 4.2). A microphone with a diaphragm having high acoustic impedance is locate

40、d in the base of the cylindrical cavity. The coupler shall be made of a material that has no negative influences on its performance. For example it should be acoustically hard and dimensionally stable. The general construction of the coupler and mounting of the microphone shall aim to reduce the res

41、ponse to vibration of any earphone or to sound outside the cavity. ANSI/ASA S3.55-2015/Part 3 / IEC 60318-3:2014 2015 Acoustical Society of America All rights reserved 2In the following, the specified tolerance shall be reduced by an amount equal to the actual expanded measurement uncertainty of the

42、 test laboratory before deciding if a device conforms to this specification. 4.2 Cavity dimensions The critical dimensions (see Figure 1) of the coupler are those that determine the shape and volume of the cavity terminated by the microphone, the static pressure equalization mechanism, the upper edg

43、e (lip) and the 45 angle. The effective acoustic volume of the coupler shall be 5,780 mm3 130 mm3. The diameter d1shall be 23.825 mm 0.080 mm. Diameter d2shall be 18.55 mm 0.16 mm. The height l2shall be 1.950 mm 0.065 mm. The angle defining the slope of the external part of the coupler shall be 45 5

44、.5. The height h of the coupler shall be calculated according to the following formula: 212141dVVVheq(1) where V1is the effective acoustic volume; Veqis the equivalent acoustic volume of the microphone; V2is the volume of the front cavity of the microphone, given by 22214Vdl(2) It is recommended tha

45、t a value of h be selected from Table 1, according to the value of the equivalent acoustic volume of the microphone. NOTE 1 It is recognized that certain combinations of coupler cavity and microphone could cause problems if the tolerance of the coupler diameter is exploited towards the smallest allo

46、wed diameter and at the same time, the tolerance of the microphone diameter is exploited towards the largest allowed diameter. Practical experience however, has proven that those problems are very unlikely to occur. NOTE 2 If the coupler described in this standard is constructed with a fixed value o

47、f h + l2= 13.41 mm regardless of the equivalent volume of the microphone, then the coupler will be identical with the NBS 9A coupler, see 11. The nominal effective acoustic volume of the type 9A coupler is: V1= Veq+ 5,640 mm31 Numbers in square brackets refer to the Bibliography. ANSI/ASA S3.20-2015

48、/Part 3 / IEC 60318-3:2014 2015 Acoustical Society of America All rights reserved 3Dimension Specification mm A 73 B 57.2 C 25.27 d123.825 d218.55 l21.95 h See 4.2, Equation (1), Table 1 H 7.5 Angle In degrees Y 25 45 25 The dimensions printed in bold are the critical dimensions that determine the s

49、hape and volume of the cavity terminated by the microphone, the capillary leak, the upper edge (lip) and the 45 angle; see 4.2. Key 1 hole for thermometer 2 microphone 3 ground shield 4 contact pin 5 venting mechanism, see 4.3. Figure 1 Dimensions of acoustic coupler ECANSI/ASA S3.55-2015/Part 3 / IEC 60318-3:2014 2015 Acoustical Society of America All rights reserved 4Table 1 Height of the coupler as a function of the acoustic volume of the microphone Equivalent acoustic volume of the microphone