BS EN 50332-1-2013 Sound system equipment Headphones and earphones associated with personal music players Maximum sound pressure level measurement methodology General method for o.pdf

1、BSI Standards PublicationBS EN 50332-1:2013Sound system equipment: Headphones and earphones associated with personal music players Maximum sound pressure level measurement methodologyPart 1: General method for “one package equipment“BS EN 50332-1:2013 BRITISH STANDARDNational forewordThis British St

2、andard is the UK implementation of EN 50332-1:2013. It supersedes BS EN 50332-1:2000, which will be withdrawn on 23 September 2016.The UK participation in its preparation was entrusted to Technical Committee EPL/108, Safety of electronic equipment within the field of audio/video, information technol

3、ogy and communication technology.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institu

4、tion 2013. Published by BSI Standards Limited 2013ISBN 978 0 580 82736 5ICS 17.140.50; 33.160.50Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2013.A

5、mendments/corrigenda issued since publicationDate Text affectedBS EN 50332-1:2013EUROPEAN STANDARD EN 50332-1 NORME EUROPENNE EUROPISCHE NORM October 2013 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotec

6、hnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B - 1000 Brussels 2013 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 50332-1:2013 E ICS 17.140.50; 33.160.50 Supersedes EN 50332-1:2000 English version Sound syste

7、m equipment: Headphones and earphones associated with personal music players - Maximum sound pressure level measurement methodology - Part 1: General method for “one package equipment“ Equipement de systmes acoustiques: Casques et couteurs associs avec un baladeur - Mthode de mesure de niveau maxima

8、l de pression acoustique - Partie 1: Mthode gnrale pour “un quipement complet“ Elektroakustische Gerte: Kopfhrer und Ohrhrer in Verbindung mit tragbaren Audiogerten - Verfahren zur Messung des maximalen Schalldruckpegels - Teil 1: Allgemeines Verfahren fr “Original-Gerte-Sets“ This European Standard

9、 was approved by CENELEC on 2013-09-23. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning

10、such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member i

11、nto its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of

12、 Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 50332-1:2013EN 50332-1:2013 - 2 - Contents Page Forewo

13、rd 3 1 Scope . 4 2 Normative references . 4 3 Terms and definitions 5 4 Measuring principle . 5 4.1 General description 5 4.2 Measuring principle 6 5 Test signal . 6 5.1 General 6 5.2 Test signal level for analogue recorders 7 5.3 Test signal level for FM radio . 7 5.4 Test signal level for digital

14、music players 7 6 Measuring arrangement and test protocol 7 6.1 General 7 6.2 Headphone fit . 8 6.3 Operating conditions 8 6.4 Measurements and evaluation . 9 Bibliography . 10 BS EN 50332-1:2013- 3 - EN 50332-1:2013 Foreword This document (EN 50332-1:2013) has been prepared by CLC/TC 108X, “Safety

15、of electronic equipment within the fields of Audio/Video, Information Technology and Communication Technology“. The following dates are fixed: latest date by which this document has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2014-09-2

16、3 latest date by which the national standards conflicting with this document have to be withdrawn (dow) 2016-09-23 This document supersedes EN 50332-1:2000. EN 50332-1:2013 includes the following significant technical changes with respect to EN 50332-1:2000: - deletion of limits; - addition of digit

17、al signals; - adaptations to use the term “personal music players“. EN 50332, Sound system equipment: Headphones and earphones associated with personal music players Maximum sound pressure level measurement methodology, is composed with the following parts: Part 1: General method for “one package eq

18、uipment“; Part 2: Matching of sets with headphones if either or both are offered separately, or are offered as one package equipment but with standardised connectors between the two allowing to combine components of different manufacturers or different design. _ BS EN 50332-1:2013EN 50332-1:2013 - 4

19、 - 1 Scope The scope of this European Standard is to set up a suitable measuring methodology allowing accurate measurement of the maximum sound pressure level produced by consumers headphones and earphones when associated with personal music players. NOTE This standard does not apply to acoustically

20、 open or acoustically closed headphones associated with mains operated Hi-Fi home equipement nor does it apply to headphones for medical purposes (hard of hearing etc.) or to headphones or similar parts being part of active hearing protection systems. Other requirements for safety, e.g. for noise pr

21、otection in offices and industry are not affected by this standard. Requested features: The method should be reproducible and easily applicable to every type and shape of headphone or earphone available on the market (good mechanical adaptability). As safety and health are addressed, the method shou

22、ld faithfully reflect the pressure level effective at the users ear (good correlation with subjective tests) to support protection against excessive sound pressure from personal music players (the limits themselves are found in EN 60950-1:2006/A12:2011 and EN 60065:2002/A12:2011 respectively). And f

23、inally, it is desirable to establish a global measuring procedure, including each component in the chain: Portable set + specific test signal + associated headphone or earphone. The standard is split into two parts: Part 1 deals with sets provided as a package equipment by the manufacturer. In this

24、case, “Personal music players“ means the association of one set (compact cassette player, FM radio receiver, digital media player, streaming audio player) with supplied headphones or earphones. Part 2 gives guidelines to associate portable audio sets (FM radio receiver, digital media player, streami

25、ng audio player) with headphones or earphones provided separately by any source. And the package sets with standardised connectors or interfaces between the two allowing to combine components of different manufacturers or different design. 2 Normative references The following documents, in whole or

26、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 any amendments) applies. HD 483.1 S2, Sound system equipment Part 1:

27、General (IEC 60268-1) EN 50332-2:2013, Sound system equipment: Headphones and earphones associated with personal music players Maximum sound pressure level measurement methodology Part 2: Matching of sets with headphones if either or both are offered separately, or are offered as one package equipme

28、nt but with standardised connectors between the two allowing to combine components of different manufacturers or different design EN 60094-7, Magnetic tape sound recording and reproducing systems Part 7: Cassette for commercial tape records and domestic use (IEC 60094-7) EN 60268-7, Sound system equ

29、ipment Part 7: Headphones and earphones (IEC 60268-7) EN 60315-4, Methods of measurement on radio receivers of various classes of emission Part 4: Receivers for frequency-modulated sound broadcasting emissions (IEC 60315-4) BS EN 50332-1:2013- 5 - EN 50332-1:2013 EN 60318-4, Electroacoustics Simulat

30、ors of human head and ear Part 4: Occluded-ear simulator for the measurement of earphones coupled to the ear by means of ear inserts (IEC 60318-4) EN 61260, Elecroacoustics Octave-band and fractional-octave-band filters (IEC 61260) EN 61672-1, Electoacoustics Sound level meters Part 1: Specification

31、s (IEC 61672-1) IEC 60318-7, Electroacoustics Simulators of human head and ear Part 7: Head and torso simulator for acoustic measurement of hearing aids 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 equivalent continuous A-weighted sound pr

32、essure level LAeq,Tequivalent continuous A-weighted sound pressure level (LAeq,T) defined in EN 61672-1 as follows: ( )LTp t dt p dBAAeq T Att,lg=10120212where LAeq,T is the equivalent continuous A-weighted sound pressure level re 20 Pa, determined over a time integration interval T = t2 t1; pA(t)is

33、 the instantaneous A-weighted sound pressure of the sound signal; p0is the reference sound pressure of 20 Pa 4 Measuring principle 4.1 General description The free field frequency response of a head and torso simulator is defined as follows: The difference, as a function of frequency, between the so

34、und pressure level at the ear simulator microphone with the reference point of the manikin at the test point and the sound pressure level at the test point with the manikin absent from a sound source at the 0 degree azimuth and 0 degree elevation angles. The diffuse field frequency response of a hea

35、d and torso simulator is defined as follows: The difference, as a function of frequency, between the sound pressure level at the ear simulator microphone with the reference point of the manikin at the test point and the sound pressure level at the test point with the manikin absent from a sound fiel

36、d with a high number of reflections that, at any given point in that diffuse field, sound arrives from all angles in a uniform manner. The sound pressure level produced by headphones or earphones can be measured by subjective methods or by objective methods. BS EN 50332-1:2013EN 50332-1:2013 - 6 - T

37、he reference method for evaluating the sound pressure level emitted by earphones is a psycho acoustic method known as “equal loudness“ (EN 60268-7). It consists in using human test subjects to compare the level of sound emitted by a speaker to that emitted by an earphone. Nevertheless, this subjecti

38、ve method becomes inadequate and hazardous when high levels are to be evaluated. The solution is to use an objective measurement method, giving both a good reproducibility and a good correlation with subjective tests. 4.2 Measuring principle This standard is based on the use of a Head and Torso Simu

39、lator (HATS). The manikin in accordance with IEC 60318-7 is fitted with an occluded ear simulator (as described in EN 60318-4) and an ear canal extension (8,8 mm length and diameter 7,5 mm 0,02 mm). Alternatively, the HATS as described in ITU-T P.58 in conjunction with ITU-T P.57 may be used, which

40、is usually used for telephonometric use. NOTE 1 Industrial realisation of these simulators use pinnaes of different material properties leading to different results. Thus, the type of pinnae needs to be stated in the measurement protocol. NOTE 2 Because the full range of equipment covered by this st

41、andard used to be measured with two different types of HATS, this standard offers to select between both. The sound pressure level measured by the ear simulator microphone represents the pressure found at eardrum level and differs from that of the free field or diffuse field pressure by the HATS tra

42、nsfer function. Free field (0-0 free field) or diffuse field response shall be used. Weighting curve A shall be used. The results are given as “(free field) or (diffuse field) related A-weighted equivalent continuous sound pressure levels (LAeq)”. 5 Test signal 5.1 General Actual musical signals are

43、 continuously fluctuating in both amplitude and spectral contents and thus cannot be used as test signals. As the frequency response curve of earphones may show considerable fluctuations, accurate measurements cannot be performed using a sinusoidal signal at a determined frequency (e.g. 1 kHz). The

44、test signal shall therefore be a full audio frequency band for the equipment under test, the spectral content of which is representative of the musical signals. The test signal used to determine the maximum sound pressure level of headphones shall be programme simulation noise, as defined in HD 483.

45、1 S2. NOTE 1 HD 483.1 S2 defines a test signal called “programme simulation signal“ described as: “A signal whose mean power spectral density closely resembles the average of the mean power spectral densities of a wide range of programme material, including both speech and music of several kinds“. T

46、his signal is a weighted stationary Gaussian noise and can be obtained from pink noise with a suitable filter network. This programme simulation noise shall have a crest factor ranging between 1,8 and 2,2. Thus, this signal will be easy to record on various media. BS EN 50332-1:2013- 7 - EN 50332-1:

47、2013 NOTE 2 Analog noise generated with higher crest factor can be adjusted to the given range by clipping. For digital interfaces this value remains if the analog peak values do not leave the A/D conversion range. Since portable cassette and CD players are playback only devices, it is necessary to

48、define a reference cassette and a reference CD for test. The test signal level is a major issue, as the whole measuring process will depend on this setting. 5.2 Test signal level for analogue recorders With analogue tape recording on compact cassette, “0 dB“ level recording corresponds by definition

49、 to a flux value of 250 nWb/m at a frequency of 315 Hz (EN 60094-2). The recording level of the test cassette shall be set considering both the frequency spectrum and the crest factor of programme simulation noise: the test recording tape shall be type 1 magnetic tape according to EN 60094-7; the test signal shall be recorded at an RMS value of - 6 dB (ref 250 nWb/m at 315 Hz); the noise reduction system shall be switched off. 5.3 Test signal level for FM radio Measurements on