1、BRITISH STANDARDBS EN ISO 389-7:2005Acoustics Reference zero for the calibration of audiometric equipment Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditionsThe European Standard EN ISO 389-7:2005 has the status of a British StandardICS 13.140g49g50g3g38g50
2、g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN ISO 389-7:2005This British Standard was published under the authority of the Standards Policy and Strategy C
3、ommittee on 23 January 2006 BSI 23 January 2006ISBN 0 580 47431 3National forewordThis British Standard is the official English language version of EN ISO 389-7:2005. It is identical with ISO 389-7:2005. It supersedes BS EN ISO 389-7:1998 which is withdrawn.The UK participation in its preparation wa
4、s entrusted by Technical Committee EH/1, Acoustics, to Subcommittee EH/1/1, Hearing, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on request to its secretary.Cross-referencesThe British Standards which implement international or European p
5、ublications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the
6、necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the
7、interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.Summary of pagesThis document comprises a front cover, an inside front cover, the EN ISO title page, the EN ISO foreword page, the ISO title
8、page, pages ii to iv, pages 1 to 10, an inside back cover and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 389-7November 2005
9、ICS 13.140 Supersedes EN ISO 389-7:1998 English VersionAcoustics - Reference zero for the calibration of audiometricequipment - Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions (ISO 389-7:2005)Acoustique - Zro de rfrence pour ltalonnagedquipements audiom
10、triques - Partie 7: Niveau liminairede rfrence dans des conditions dcoute en champ libreet en champ diffus (ISO 389-7:2005)Akustik - Standard-Bezugspegel fr die Kalibrierung vonaudiometrischen Gerten - Teil 7: Bezugshrschwellenunter Freifeld- und Diffusfeldbedingungen (ISO 389-7:2005)This European S
11、tandard was approved by CEN on 28 October 2005.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concernin
12、g such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own languag
13、e and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
14、Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2005 CEN All rights of exploitation in any
15、form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 389-7:2005: EForeword This document (EN ISO 389-7:2005) has been prepared by Technical Committee ISO/TC 43 “Acoustics“ in collaboration with Technical Committee CEN/TC 211 “Acoustics“, the secretariat of which is held b
16、y DS. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by May 2006, and conflicting national standards shall be withdrawn at the latest by May 2006. This document supersedes EN ISO 389-7:1998. Accordi
17、ng to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania
18、, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 389-7:2005 has been approved by CEN as EN ISO 389-7:2005 without any modifications. EN ISO 389-7:2005Reference numberISO 389-7:2005(E)INTE
19、RNATIONAL STANDARD ISO389-7Second edition2005-11-01Acoustics Reference zero for the calibration of audiometric equipment Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions Acoustique Zro de rfrence pour ltalonnage dquipements audiomtriques Partie 7: Niveau
20、 liminaire de rfrence dans des conditions dcoute en champ libre et en champ diffus EN ISO 389-7:2005ii iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is nor
21、mally 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-governmental, in liaison with ISO, also take part in
22、the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepar
23、e International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that som
24、e 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. ISO 389-7 was prepared by Technical Committee ISO/TC 43, Acoustics. This second edition cancels and replaces the first edition (ISO 389-7:1996), wh
25、ich has been technically revised. ISO 389 consists of the following parts, under the general title Acoustics Reference zero for the calibration of audiometric equipment: Part 1: Reference equivalent threshold sound pressure levels for pure tones and supra-aural earphones Part 2: Reference equivalent
26、 threshold sound pressure levels for pure tones and insert earphones Part 3: Reference equivalent threshold force levels for pure tones and bone vibrators Part 4: Reference levels for narrow-band masking noise Part 5: Reference equivalent threshold sound pressure levels for pure tones in the frequen
27、cy range 8 kHz to 16 kHz Part 6: Reference hearing threshold levels for test signals of short duration Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions Part 8: Reference equivalent threshold sound pressure levels for pure tones and circumaural earphones
28、EN ISO 389-7:2005iv Introduction In some audiological applications the test signals are delivered by means of loudspeakers, either in a free sound field or in a diffuse sound field. This part of ISO 389 specifies the reference zero for the calibration of audiometric equipment used for sound field au
29、diometry. Corresponding audiometric test methods are specified in ISO 8253-1 and ISO 8253-2. In common with other subjective phenomena, the threshold of hearing varies in detail from person to person but, for a group of otologically normal persons within a restricted age range, values for the centra
30、l tendency can be determined to characterize the group. This and other parts of ISO 389 specify threshold data applicable to otologically normal persons in the age range from 18 years to 25 years. The data specified in this part of ISO 389 relate to a) pure tones heard under conditions of binaural l
31、istening in free progressive plane waves with the subject directly facing the source of sound (frontal incidence), and with the sound pressure level measured in the free progressive wave at the centre position of the listeners head with the listener absent; b) one-third-octave bands of (white or pin
32、k) noise heard under conditions of binaural listening in a diffuse sound field with the sound pressure level measured in the sound field at the centre position of the listeners head with the listener absent. For frequencies up to 8 kHz, each set of data may be equally applied to any other bands of (
33、white or pink) noise for which the bandwidth is less than the critical bandwidth. The data are based on an assessment of technical information provided by laboratories in different countries representing the most reliable data available at the time. For information, a note on the derivation of the r
34、eference values and the origin of the data is given in Annex A. EN ISO 389-7:20051Acoustics Reference zero for the calibration of audiometric equipment Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions 1 Scope This part of ISO 389 specifies a reference th
35、reshold of hearing for the calibration of audiometric equipment used under the following conditions. a) The sound field in the absence of the listener consists of either a free progressive plane wave (free field) or a diffuse sound field, as specified in ISO 8253-2. In the case of a free field, the
36、source of sound is directly in front of the listener (frontal incidence). b) The sound signals are pure (sinusoidal) tones in the case of free-field conditions and one-third octave bands of (white or pink) noise in the case of diffuse-field conditions. c) The sound pressure level is measured in the
37、absence of the listener at the position where the centre of the listeners head would be. d) Listening is binaural. NOTE 1 Correction values for the threshold of hearing under free-field listening conditions and selected angles of sound incidence (45 and 90) deviating from frontal incidence are given
38、 in ISO 8253-2 for information. NOTE 2 Other conditions are given in Bibliographic Reference 1. The data are given in numerical form for the preferred frequencies in the one-third-octave series from 20 Hz to 16 000 Hz inclusive in accordance with ISO 266 and, in addition, for some intermediate audio
39、metric frequencies up to 18 000 Hz. It should be emphasized that the threshold data differ from the audiometric zero specified in ISO 389-1, ISO 389-2, ISO/TR 389-5 and ISO 389-8, since the latter refer to monaural listening through earphones with sound pressure levels referred to specified couplers
40、 and ear simulators. Direct comparison between the data in the parts of ISO 389 mentioned above and in this part of ISO 389 is therefore not appropriate. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the e
41、dition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 8253-2, Acoustics Audiometric test methods Part 2: Sound field audiometry with pure tone and narrow-band test signals EN ISO 389-7:20052 3 Terms and definitions For the
42、 purposes of this document, the following terms and definitions apply. 3.1 threshold of hearing level of a sound at which, under specified conditions, a person gives 50 % of correct detection responses on repeated trials NOTE The results of threshold determination depend to a certain degree on the t
43、est procedure used. The data presented in the ISO 389 series are all based on the use of the threshold test procedures defined in ISO 8253-1. When a test procedure with other characteristics is used, differences of up to several decibels on average may be expected. 3.2 otologically normal person per
44、son in a normal state of health who is free from all signs or symptoms of ear disease and from obstructing wax in the ear canals, and who has no history of undue exposure to noise, exposure to potentially ototoxic drugs, or familial hearing loss 3.3 reference threshold of hearing at a specified freq
45、uency, the sound pressure level of a pure tone or a one-third-octave band of noise corresponding to the median value of the binaural thresholds of hearing of otologically normal persons within the age limits from 18 years to 25 years inclusive 3.4 free sound field sound field where the boundaries of
46、 the room exert a negligible effect on the sound waves 3.5 diffuse sound field sound field consisting of sound waves arriving at a given location more or less simultaneously from all directions with equal probability and level 4 Specification The reference thresholds of hearing for the listening con
47、ditions specified in Clause 1 are given in Table 1. This table also gives the differences between sound pressure levels of one-third-octave bands of noise in a diffuse sound field and the sound pressure levels of pure tones in a frontally incident free progressive wave for equal thresholds of hearin
48、g. A graphical illustration of the reference thresholds of hearing is given in Figure 1. EN ISO 389-7:20053Table 1 Reference thresholds of hearing for the listening conditions specified in Clause 1 and differences between sound pressure levels in the two types of sound field Frequency Reference thre
49、shold of hearing under the condition of Difference free-field listening (frontal incidence) diffuse-field listening f Tf(ref. 20 Pa) Tf(ref. 20 Pa) L = Tf TfHz dB dB dB 20 78,5 a78,5 0 25 68,7 68,7 31,5 59,5 59,5 0 40 51,1 51,1 50 44,0 44,0 0 63 37,5 37,5 80 31,5 31,5 0 100 26,5 26,5 125 22,1 22,1 0 160 17,9 17,9 200 14,4 14,4 0 250 11,4 11,4 315 8,6 8,4 0,2 400 6,2 5,8 0,4 500 4,4 3,8 0,6 630 3,0 2,1 0,9 750 2,4 1,2 1,2 800 2,2 1,0 1,2 1 000 2,4 0,8 1,6 1 250 3,5 1,9 1,6 1 500 2,4 1,0 1,4 1 600 1,7 0
