EN ISO 389-7:1998
(Main)Acoustics - Reference zero for the calibration of audiometric equipment - Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions (ISO 389-7:1996)
Acoustics - Reference zero for the calibration of audiometric equipment - Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions (ISO 389-7:1996)
Akustik - Standard-Bezugspegel für die Kalibrierung von audiometrischen Geräten - Teil 7: Bezugshörschwellen unter Freifeld- und Diffusfeldbedingungen (ISO 389-7:1996)
Dieser Teil von ISO 389 legt eine Bezugshörschwelle zur Kalibrierung audiometrischer Geräte fest, die unter den folgenden Bedingungen benutzt werden: a) das Schallfeld besteht bei Abwesenheit des Hörers entweder aus einer sich frei ausbreitenden ebenen Welle (Freifeld) oder ist ein diffuses Schallfeld. Im Falle der ebenen sich frei ausbreitenden Schallwelle befindet sich die Schallquelle direkt vor dem Hörer (frontaler Schalleinfall).
Acoustique - Zéro de référence pour l'étalonnage d'équipements audiométriques - Partie 7: Niveau liminaire de référence dans des conditions d'écoute en champ libre et en champ diffus (ISO 389-7:1996)
Akustika - Referenčna ničla za umerjanje avdiometrov - 7. del: Referenčni prag slišnosti v prostem in difuznem polju (ISO 389-7:1996)
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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Akustik - Standard-Bezugspegel für die Kalibrierung von audiometrischen Geräten - Teil 7: Bezugshörschwellen unter Freifeld- und Diffusfeldbedingungen (ISO 389-7:1996)Acoustique - Zéro de référence pour l'étalonnage d'équipements audiométriques - Partie 7: Niveau liminaire de référence dans des conditions d'écoute en champ libre et en champ diffus (ISO 389-7:1996)Acoustics - Reference zero for the calibration of audiometric equipment - Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions (ISO 389-7:1996)13.140Vpliv hrupa na ljudiNoise with respect to human beingsICS:Ta slovenski standard je istoveten z:EN ISO 389-7:1998SIST EN ISO 389-7:1999en01-november-1999SIST EN ISO 389-7:1999SLOVENSKI
STANDARD
SIST EN ISO 389-7:1999
SIST EN ISO 389-7:1999
SIST EN ISO 389-7:1999
SIST EN ISO 389-7:1999
SIST EN ISO 389-7:1999
INTERNATIONAL STANDARD First edition 1996-l 2-15 Acoustics - Reference zero for the calibration of audiometric equipment - Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions Acoustique - Z&o de rdfgrence pour Malonnage d’hquipements a udiomk triques - Parfie 7: Niveau liminaire de rkfkrence dans des conditions d’koute en champ libre et en champ diffus Reference number IS0 389-7: 1996(E) SIST EN ISO 389-7:1999
IS0 389-7: 1996(E) Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 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 the work. IS0 collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. 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 5% of the member bodies casting a vote. International Standard IS0 389-7 was prepared by Technical Committee ISO/TC 43, Acoustics. This first edition of IS0 389-7 constitutes a partial revision of IS0 266:1987 with respect to the threshold of hearing for pure tones under free-field listening conditions 5 [ISO 226:1987, table 1 (column 4) and annex A (MAF-curve)], the threshold of hearing for one-third-octave noise bands under diffuse-field listening conditions Tj! [ISO 226:1987, table 4 (column 3)], and the difference between these thresholds, AL [ISO 226:1987, table 4 (column 2)]. The equal-loudness level contours contained in IS0 226 are at present under revision within ISOTTC 43 and are not covered by this part of IS0 389. IS0 389 consists of the following parts, under the general title Acoustics - Reference zero for the calibration of audiometric equipment: - Part I: Reference equivalent threshold sound pressure levels for pure tones and supra-aural earphone - Part 2: Reference equivalent threshold sound pressure levels for pure tones and insert earphones - Part 3: Reference equivalent threshold force levels for pure tones and bone vibrators 0 IS0 1996 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case postale 56 l CH-1211 Geneve 20 l Switzerland Printed in Switzerland ii SIST EN ISO 389-7:1999
0 IS0 IS0 389-7: 1996(E) - Part 4: Reference levels for narrow-band masking noise - Par? 5: Reference equivalent threshold sound pressure levels for pure tones in the frequency range 8 kHz to 16 kHz - Part 7: Reference threshold of hearing under free-field and diffuse- field listening conditions Part 1 will be a re-issue of IS0 389:1991. Annexes A and B of this part of IS0 389 are for information only. SIST EN ISO 389-7:1999
IS0 389-7: 1996(E) 0 IS0 Introduction Each part of IS0 389 specifies a specific reference zero for the calibration of audiometric equipment. IS0 389:1991 (to be re-issued as IS0 389-l) and IS0 389-2 are applicable to audiometric equipment for the transmission of pure tones by means of supra-aural or insert earphones, respectively. Corresponding audiometric test methods are specified in IS0 8253-l. In some audiological applications it may, however, be desirable to deliver the test signals by means of loudspeakers, either in a free sound field or in a diffuse sound field. Corresponding audiometric test methods are specified in IS0 8253-2. This part of IS0 389 specifies the reference zero for the calibration of audiometric equipment used for sound field audiometry. 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 central tendency can be determined to characterize the group. This and other parts of IS0 389 specify threshold data applicable to otologically normal persons in the age range from 18 to 25 years. Compared with IS0 226, a more stringent age criterion has been applied in order to define a population as homogeneous as practicable with respect to the relationship between the threshold of hearing and age. . The data specified in this part of IS0 389 relate to a) pure tones heard under conditions of binaural listening 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 listener’s head with the listener absent; b) one-third-octave bands of (white or pink) 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 listener’s head with the listener absent. For frequencies up to 8 kHz, each set of data may be equally applied to any other bands of (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 reference values and the origin of the data is given in annex A and a bibliography is given in annex B. IV SIST EN ISO 389-7:1999
INTERNATIONAL STANDARD o IS0 IS0 389-7: 1996(E) Acoustics - 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 IS0 389 specifies a reference threshold of hearing for the calibration of audiometric equipment used under the following conditions. a) b) C) d) e) 0 9) The sound field in the absence of the listener consists of either a free progressive plane wave (free field) or a diffuse sound field. In the case of a free progressive plane wave, the source of sound is directly in front of the listener (frontal incidence). NOTE 1 Correction values for the threshold of hearing under free-field listening conditions and selected angles of sound incidence deviating from frontal incidence are given in IS0 8253-2 for information. The sound signals are pure (sinusoidal) tones in the case of free-field conditions, and one-third-octave band of (white or pink) noise in the case of diffuse-field conditions. The sound pressure level is measured in the absence of the listener at the position where the centre of the listener’s head would be. Listening is binaural. The sound pressure levels corresponding to the reference threshold of hearing are determined by the median value of the thresholds of an adequately large group of listeners. The listeners are otologically normal persons in the age range from 18 to 25 years inclusive. NOTE 2 The data given in this part of IS0 389 have been derived from listeners who have hearing threshold levels of 10 dB or less according to IS0 389:1991. This selection criterion is not identical with that used when data for IS0 3897 991 were derived. The threshold of hearing is determined by means of the bracketing or ascending method, as specified in IS0 8253-l. 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 IS0 266 and for intermediate audiometric frequencies. Figure 1 gives a graphical presentation. It should be emphasized that the threshold data differ from the audiometric zero specified in IS0 389:1991 and IS0 389-2, since the latter refer to monaural listening through earphones with sound pressure levels referred to 1 SIST EN ISO 389-7:1999
IS0 389-7: 1996(E) 0 IS0 specified couplers and ear simulators. Direct comparison between the data in IS0 389:1991 or IS0 389-2, respectively, and in this part of IS0 389 is therefore not appropriate. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of IS0 389. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of IS0 389 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers of currently valid International Standards. IS0 266:- ‘), Acoustics - Preferred frequencies. IS0 8253-1:1989, Acoustics - Audiometric test methods - Part I: Basic pure tone air and bone conduction threshold audiometry. 3 Definitions For the purposes of this part of IS0 389, the following 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. 3.2 otologically normal person: Person 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 frequency, 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 to 25 years inclusive. 3.4 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 conditions 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 hearing. A graphical illustration of the reference thresholds of hearing is given in figure 1. 1) To be published. (Revision of IS0 266
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