EN 60268-4:2014

SLOVENSKI STANDARD
01-december-2014
1DGRPHãþD
SIST EN 60268-4:2010
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Sound system equipment - Part 4: Microphones (IEC 60268-4:2014)
Elektroakustische Geräte - Teil 4: Mikrofone (IEC 60268-4:2014)
Equipements pour systèmes électroacoustiques - Partie 4: Microphones (CEI 60268-
4:2014)
Ta slovenski standard je istoveten z: EN 60268-4:2014
ICS:
33.160.50 Pribor Accessories
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 60268-4
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2014
ICS 33.160.50 Supersedes EN 60268-4:2010
English Version
Sound system equipment - Part 4: Microphones
(IEC 60268-4:2014)
Equipements pour systèmes électroacoustiques - Partie 4: Elektroakustische Geräte - Teil 4: Mikrofone
Microphones (IEC 60268-4:2014)
(CEI 60268-4:2014)
This European Standard was approved by CENELEC on 2014-07-24. 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 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 into 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 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.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 60268-4:2014 E
Foreword
The text of document 100/2116/CDV, future edition 5 of IEC 60268-4, prepared by IEC/TC 100 "Audio,
video and multimedia systems and equipment" was submitted to the IEC-CENELEC parallel vote and
approved by CENELEC as EN 60268-4:2014.
The following dates are fixed:
• latest date by which the document has (dop) 2015-04-24
to be implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2017-07-24
• latest date by which the national
standards conflicting with the
document have to be withdrawn
This document supersedes EN 60268-4:2010.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent
rights.
Endorsement notice
The text of the International Standard IEC 60268-4:2014 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:

CISPR 22 NOTE Harmonized as EN 55022.
IEC 60065:2001 NOTE Harmonized as EN 60065:2002.
IEC 60065/A1:2005 NOTE Harmonized as EN 60065/A1:2006.
IEC 60065/A2:2010 NOTE Harmonized as EN 60065/A2:2010.
IEC 60958-4 NOTE Harmonized as EN 60958-4.
IEC 61000-3-2 NOTE Harmonized as EN 61000-3-2.
IEC 61000-3-3 NOTE Harmonized as EN 61000-3-3.
IEC 61606 (Series) NOTE Harmonized as EN 61606 (Series).
IEC 61672-1 NOTE Harmonized as EN 61672-1.

- 3 - EN 60268-4:2014
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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 any amendments) applies.
NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant EN/HD

applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Publication Year Title EN/HD Year

IEC 60268-1 1985 Sound system equipment -- Part 1: General HD 483.1 S2 1989
+A1 1988  - -
+A2 1988  - -
IEC 60268-2 1987 Sound system equipment -- Part 2: HD 483.2 S2 1993
Explanation of general terms and calculation
methods
+A1 1991  - -
IEC 60268-3 2013 Sound system equipment -- Part 3: EN 60268-3 2013
Amplifiers (GMT)
IEC 60268-5 2003 Sound system equipment -- Part 5: EN 60268-5 2003
Loudspeakers
+A1 2007  +A1 2009
IEC 60268-11 1987 Sound system equipment -- Part 11: HD 483.11 S3 1993
Application of connectors for the
interconnection of sound system
components
+A1 1989  - -
+A2 1991  - -
IEC 60268-12 1987 Sound system equipment -- Part 12: EN 60268-12 1995
Application of connectors for broadcast and
similar use
+A1 1991  - -
+A2 1994  +A2 1995
IEC 61000-4-2 2008 Electromagnetic compatibility (EMC) -- Part EN 61000-4-2 2009
4-2: Testing and measurement techniques -
Electrostatic discharge immunity test
IEC 61000-4-3 2006 Electromagnetic compatibility (EMC) -- Part EN 61000-4-3 2006
4-3: Testing and measurement techniques -
Radiated, radio-frequency, electromagnetic
field immunity test
IEC 61000-4-4 2012 Electromagnetic compatibility (EMC) -- Part EN 61000-4-4 2012
4-4: Testing and measurement techniques -
Electrical fast transient/burst immunity test
IEC 61000-4-6 2008 Electromagnetic compatibility (EMC) -- Part EN 61000-4-6 2009
4-6: Testing and measurement techniques -
Immunity to conducted disturbances,
induced by radio-frequency fields
IEC 61000-4-8 2009 Electromagnetic compatibility (EMC) -- Part EN 61000-4-8 2010
4-8: Testing and measurement techniques -
Power frequency magnetic field immunity
test
IEC 61000-4-16 -  Electromagnetic compatibility (EMC) - Part - -
4-16: Testing and measurement techniques
- Test for immunity to conducted, common
mode disturbances in the frequency range 0
Hz to 150 kHz
IEC 61000-4-17 1999 Electromagnetic compatibility (EMC) - Part - -
4-17: Testing and measurement techniques
- Ripple on d.c. input power port immunity
test
+A1 2001  +A1 2004
+A2 2008  +A2 2009
IEC 61260-1 2014 Electroacoustics - Octave-band and EN 61260-1 2014
fractional-octave-band filters -- Part 1:
Specifications
IEC 61938 2013 Multimedia systems - Guide to the EN 61938 2013
recommended characteristics of analogue
interfaces to achieve interoperability
CISPR 35 -  Electromagnetic compatibility of multimedia - -
equipment - Immunity requirements
ITU-T 1996 Artificial mouth - -
Recommendation
P.51
EN 55103-2 2009 Electromagnetic compatibility – Product - -
family standard for audio, video, audio-visual
and entertainment lighting control apparatus
for professional use – Part 2: Immunity
EN 300 422-2 V1.3.1 2011 Electromagnetic compatibility and radio - -
spectrum matters (ERM) – Wireless
microphones in the 25 MHz to 3 GHz
frequency range – Part 2: Harmonized EN
covering the essential requirements of
article 3.2 of the R&TTE Directive

IEC 60268-4 ®
Edition 5.0 2014-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Sound system equipment –
Part 4: Microphones
Équipements pour systèmes électroacoustiques –

Partie 4: Microphones
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XA
ICS 33.160.50 ISBN 978-2-8322-1586-9

– 2 – IEC 60268-4:2014 © IEC 2014
CONTENTS
FOREWORD . 6
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 General conditions . 10
4.1 General . 10
4.2 Measurement conditions . 10
4.2.1 General . 10
4.2.2 Rated conditions . 11
5 Particular conditions . 11
5.1 Pre-conditioning . 11
5.2 Sound source . 12
5.3 Measurement of sound pressure . 12
5.4 Voltage measuring system . 12
5.5 Acoustical environment . 12
5.5.1 General . 12
5.5.2 Free-field conditions . 12
5.5.3 Diffuse field conditions . 14
5.5.4 Microphone coupled to a sound source by means of a small cavity
coupler . 15
5.6 Methods of measuring frequency response . 15
5.6.1 Point-by-point and continuous sweep frequency methods . 15
5.6.2 Calibration methods . 16
5.7 Overall accuracy . 16
5.8 Graphical presentation of results . 16
6 Type description (acoustical behaviour) . 16
6.1 Principle of the transducer . 16
6.2 Type of microphone . 16
6.3 Type of directional response characteristics . 17
6.4 Application profile . 17
7 Terminals and controls . 17
7.1 Marking . 17
7.2 Connectors and electrical interface values . 17
8 Reference point and axis . 17
8.1 Reference point . 17
8.2 Reference axis . 18
9 Rated power supply . 18
9.1 Characteristics to be specified . 18
9.2 Method of measurement . 18
10 Electrical impedance . 18
10.1 Internal impedance . 18
10.1.1 Characteristic to be specified . 18
10.1.2 Methods of measurement . 18
10.2 Rated impedance . 19
10.3 Rated minimum permitted load impedance . 19

IEC 60268-4:2014 © IEC 2014 – 3 –
11 Sensitivity . 19
11.1 General . 19
11.2 Sensitivities with respect to acoustical environment . 20
11.2.1 Free-field sensitivity . 20
11.2.2 Diffuse-field sensitivity . 20
11.2.3 Close-talking or near-field sensitivity . 21
11.2.4 Pressure sensitivity . 21
11.3 Rated sensitivity . 22
12 Response . 22
12.1 Frequency response . 22
12.1.1 Characteristic to be specified . 22
12.1.2 Method of measurement . 23
12.1.3 Graphical presentation of results . 23
12.2 Effective frequency range . 23
12.2.1 Characteristic to be specified . 23
12.2.2 Method of measurement . 23
13 Directional characteristics . 23
13.1 Directional pattern . 23
13.1.1 Characteristic to be specified . 23
13.1.2 Methods of measurement . 23
13.1.3 Graphical presentation of results . 24
13.2 Directivity index . 25
13.2.1 Characteristic to be specified . 25
13.2.2 Method of measurement . 25
14 Amplitude non-linearity . 25
14.1 General . 25
14.2 Total harmonic distortion . 25
14.2.1 Characteristic to be specified . 25
14.2.2 Method of measurement . 25
th
14.3 Harmonic distortion of the n order (n = 2, 3,.) . 26
14.3.1 Characteristic to be specified . 26
14.3.2 Method of measurement . 26
14.4 Difference frequency distortion of second order . 27
14.4.1 Characteristic to be specified . 27
14.4.2 Method of measurement . 27
15 Limiting characteristics . 27
15.1 Rated maximum permissible peak sound pressure . 27
15.2 Overload sound pressure . 27
15.2.1 Characteristic to be specified . 27
15.2.2 Method of measurement . 28
16 Balance . 28
16.1 Balance of the microphone output . 28
16.2 Balance under working conditions . 28
17 Equivalent sound pressure level due to inherent noise . 29
17.1 Characteristic to be specified . 29
17.2 Method of measurement . 29
18 Ambient conditions . 30
18.1 General . 30

– 4 – IEC 60268-4:2014 © IEC 2014
18.2 Pressure range . 30
18.3 Temperature range . 30
18.4 Relative humidity range . 30
19 External influences . 30
19.1 General . 30
19.1.1 Specification and methods of measurement . 30
19.1.2 Other external interferences . 31
19.2 Equivalent sound pressure due to mechanical vibration . 31
19.2.1 Characteristic to be specified . 31
19.2.2 Method of measurement . 31
19.3 Equivalent sound pressure due to wind . 31
19.3.1 Characteristic to be specified . 31
19.3.2 Method of measurement . 31
19.4 Transient equivalent sound pressure due to "pop" effect . 34
19.4.1 Characteristic to be specified . 34
19.4.2 Method of measurement . 36
20 Electromagnetic compatibility (EMC) . 36
20.1 Regulatory requirements . 36
20.2 Requirements for preserving programme quality . 37
20.3 Performance criteria . 38
20.3.1 Criterion A . 38
20.3.2 Criterion B . 38
20.4 Testing for immunity to disturbances in the presence of acoustical noise . 38
20.5 Immunity to frequency-modulated radiated disturbances . 38
20.6 Immunity to magnetic fields . 39
20.7 Immunity to ripple on d.c. power supply . 39
20.8 Permanent magnetic field . 39
20.9 Evaluation and reporting of the test results . 39
21 Physical characteristics . 40
21.1 Dimensions . 40
21.2 Weight . 40
21.3 Cables and connectors . 40
22 Classification of the characteristics to be specified . 40
Annex A (normative) Additional characteristics . 43
A.1 Characteristic sensitivity for speech . 43
A.1.1 Characteristic to be specified . 43
A.1.2 Method of measurement . 43
A.2 Front-to-rear sensitivity index (0° – 180°) . 44
A.2.1 Characteristic to be specified . 44
A.2.2 Method of measurement . 44
A.3 Noise-cancelling index . 44
A.3.1 Characteristic to be specified . 44
A.3.2 Method of measurement . 44
A.4 Special characteristics for stereo microphones . 45
A.4.1 General . 45
A.4.2 Included angle of an XY (left-right) microphone . 45
A.4.3 Acceptance angle . 45
Annex B (informative) Sound insulation device . 46

IEC 60268-4:2014 © IEC 2014 – 5 –
Annex C (informative) Simplified procedure for “pop” measurements . 47
C.1 General . 47
C.2 Measurement set-up . 47
C.3 Measurement procedure . 47
C.4 Approximate inclusion of different frequency responses . 48
Annex D (informative) Recommendations for professional digital microphones . 50
D.1 General . 50
D.2 Data sheets for digital microphones . 50
Bibliography . 53

Figure 1 – Balance of the output . 28
Figure 2 – Balance under working conditions . 29
Figure 3 – Measurement set-up for wind influence . 32
Figure 4 – Wind generators, type 1 (Figure 4a) and type 2 (Figure 4b) . 33
Figure 5 – Electrical and mechanical set-up for the measuring of the "pop" effect . 35
Figure B.1 – Sound insulation device . 46
Figure C.1 – Measurement set-up . 49
Figure C.2 – Test fixture for the sound field sensitivity . 49

Table 1 – Reverberation time of the empty room . 14
Table 2 – Reference signal and characteristics . 36
Table 3 – Examples of EMC regulations and standards . 37
Table 4 – Basic EMC standards and their application to microphones . 37
Table 5 – Classification of characteristics . 41
Table A.1 – Speech power weighting factor at octave-band centre frequencies . 43
Table D.1 – Classification of the characteristics recommended to be specified . 50
Table D.2 – Additional digital characteristics to be specified . 52

– 6 – IEC 60268-4:2014 © IEC 2014
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SOUND SYSTEM EQUIPMENT –
Part 4: Microphones
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60268-4 has been prepared by IEC technical committee 100:
Audio, video and multimedia systems and equipment.
This fifth edition cancels and replaces the fourth edition published in 2010, and constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
– clarification of Table 5 of classification of characteristics;
– clarification of graphical representation;
– clarification of environmental influences;
– rewritten clause for EMC;
– tolerances and more specific values for noise measurements;

IEC 60268-4:2014 © IEC 2014 – 7 –
– inclusion of near-field response for sound source-to-microphone distances of the order of
30 cm.
The text of this standard is based on the following documents:
CDV Report on voting
100/2116/CDV 100/2186/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 60268 series, under the general title Sound system equipment,
can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 8 – IEC 60268-4:2014 © IEC 2014
SOUND SYSTEM EQUIPMENT –
Part 4: Microphones
1 Scope
This part of IEC 60268 specifies methods of measurement for the electrical impedance,
sensitivity, directional response pattern, dynamic range and external influences of sound
system microphones, and also details the characteristics to be specified by the manufacturer.
It applies to sound system microphones for all applications for speech and music. It does not
apply to measurement microphones, but it does apply to each audio channel of microphones
having more than one channel, for example for stereo or similar use. It is also applicable to
flush-mounted microphones and to the analogue characteristics of microphones with digital
audio output.
For the purposes of this International Standard, a microphone includes all such devices as
transformers, pre-amplifiers, or other elements that form an integral part of the microphone,
up to the output terminals specified by the manufacturer.
The major characteristics of a microphone are considered in Clauses 6 to 21. Additional
characteristics are considered in Annex A, Annex C and Annex D.
NOTE The characteristics specified in this standard do not completely describe the subjective response of the
microphone. Further work is necessary to find new definitions and measurement procedures for a later replacement
by objective characteristics of at least some of the subjective descriptions used to describe microphone
performance.
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 any
amendments) applies.
CISPR 35:–, Electromagnetic compatibility of multimedia equipment – Immunity
requirements
IEC 60268-1:1985, Sound system equipment – Part 1: General
Amendment 1:1988
Amendment 2:1988
IEC 60268-2:1987, Sound system equipment – Part 2: Explanation of general terms and
calculation methods
Amendment 1:1991
IEC 60268-3:2013, Sound system equipment – Part 3: Amplifiers
IEC 60268-5:2003, Sound system equipment – Part 5: Loudspeakers
Amendment 1:2007
Amendment 1:2007
_____________
To be published.
IEC 60268-4:2014 © IEC 2014 – 9 –
IEC 60268-11:1987, Sound system equipment – Part 11: Application of connectors for the
interconnection of sound system components
Amendment 1:1989
Amendment 2:1991
IEC 60268-12:1987, Sound system equipment – Part 12: Application of connectors for
broadcast and similar use
Amendment 1:1991
Amendment 2:1994
IEC 61000-4-2:2008, Electromagnetic compatibility (EMC) – Part 4-2: Testing and
measurement techniques – Electrostatic discharge immunity test
IEC 61000-4-3:2006, Electromagnetic compatibility (EMC) – Part 4-3: Testing and
measurement techniques - Radiated, radio-frequency, electromagnetic field immunity test
Amendment 1:2007
Amendment 2:2010
IEC 61000-4-4:2012, Electromagnetic compatibility (EMC) – Part 4-4: Testing and
measurement techniques – Electrical fast transient/burst immunity test
IEC 61000-4-6:2008, Electromagnetic compatibility (EMC) – Part 4-6: Testing and
measurement techniques – Immunity to conducted disturbances, induced by radio-frequency
fields
IEC 61000-4-8:2009, Electromagnetic compatibility (EMC) – Part 4-8: Testing and
measurement techniques – Power frequency magnetic field immunity test
IEC 61000-4-16, Electromagnetic compatibility (EMC) – Part 4-16: Testing and measurement
techniques – Test for immunity to conducted, common mode disturbances in the frequency
range 0 Hz to 150 kHz
IEC 61000-4-17:1999, Electromagnetic compatibility (EMC) – Part 4-17: Testing and
measurement techniques - Ripple on d.c. input power port immunity test
Amendment 1:2001
Amendment 2:2008
IEC 61260-1:2014, Electroacoustics – Octave-band and fractional-octave-band filters –
Part 1: Specifications
IEC 61938:2013, Multimedia systems – Guide to the recommended characteristics of
analogue interfaces to achieve interoperability
ITU-T Recommendation P.51:1996, Artificial mouth
EN 55103-2:2009, Electromagnetic compatibility – Product family standard for audio, video,
audio-visual and entertainment lighting control apparatus for professional use – Part 2:
Immunity
EN 300 422-2 V1.3.1:2011, Electromagnetic compatibility and radio spectrum matters (ERM)
– Wireless microphones in the 25 MHz to 3 GHz frequency range – Part 2: Harmonized EN
covering the essential requirements of article 3.2 of the R&TTE Directive
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60268-1 and the
following apply.
– 10 – IEC 60268-4:2014 © IEC 2014
3.1
far-field microphone
microphone for use at a distance of more than 1 m from the source of sound
3.2
near-field microphone
microphone for use by an individual performer at a distance of approximately 30 cm
3.3
close-talking microphone
microphone for use at a distance of approximately 25 mm from the source of sound
4 General conditions
4.1 General
Special reference is made to IEC 60268-1, concerning:
• units and system of measurement;
• frequencies of measurement;
• quantities to be specified and their accuracy (see also 5.7);
• marking (see also 7.1);
• ambient conditions;
• filters, networks and measuring instruments for noise specification and measurement;
• individual specifications and type specifications;
• graphical presentation of characteristics;
• scales for graphical presentation;
• personal safety and prevention of spread of fire;
• method of producing a uniform alternating magnetic field;
• search coils for measuring the magnetic field strength,
and to IEC 61938 concerning powering of microphones.
4.2 Measurement conditions
4.2.1 General
For convenience in specifying how microphones shall be set up for measurement, three sets
of conditions have been defined in this standard, under the title of "rated conditions".
Microphones should be measured in conditions approximating those in which they are
intended to be used. Three sets of measurement conditions are specified in this standard:
free-field, near-field and close-talking. The differences between these sets of conditions are in
the distance to the sound source and the sound pressure level of the measurement.
Measurements shall be reported using at least one of these sets of conditions. Additional data
may be included, provided that the measurement conditions are specified.
Three ratings are basic to the formulation of these concepts:
– rated power supply (see 9.1);
– rated impedance (see 10.2);
– rated sensitivity (see 11.3).

IEC 60268-4:2014 © IEC 2014 – 11 –
To obtain the correct conditions for measurement, the above mentioned ratings shall be taken
from the specifications supplied by the manufacturer of the equipment.
The term "rated" applied to other characteristics relates to the specification or measurement
of the particular characteristic under rated conditions or under conditions unambiguously
connected to them. This applies, for example, to the following two characteristics:
– rated output voltage;
– rated equivalent sound pressure level due to inherent noise.
Methods of measurement are given in this standard for electrical impedance, sensitivity,
directional pattern, dynamic range and external influences. Where alternative methods are
given, the chosen method shall be specified.
4.2.2 Rated conditions
The microphone is understood to be working under rated conditions when the following
conditions are fulfilled:
– the microphone is connected to the resistive load specified in 5.4, or as specified by the
manufacturer;
– if the microphone needs a power supply, this is the rated power supply;
– the microphone (except a close-talking or near-field microphone) is placed in a sound field
meeting the free-field conditions in 5.5.2, the waves having zero degree incidence with
respect to the reference direction;
– the undisturbed sound pressure (in the absence of the microphone) in the sound field at
the reference point of the microphone is sinusoidal and set at a level of 1 Pa (94 dB SPL);
– for close-talking microphones, the microphone is placed at a stated distance, no more
than 25 mm from the artificial mouth complying with ITU-T Recommendation P.51, and the
undisturbed sound pressure in the sound field at the reference point of microphone is
sinusoidal and set at a level of 3 Pa (104 dB SPL);
– for near-field microphones, the microphone is placed at 30 cm from the artificial mouth
complying with ITU-T Recommendation P.51, and the undisturbed sound pressure in the
sound field at the reference point of microphone is sinusoidal and set at a level of 1 Pa
(94 dB SPL);
– if a special microphone needs a different measurement level, it shall be stated in the
technical data together with the reason for this. Levels related to the normal reference
level of 94 dB by multiples of 10 dB are preferred;
– controls, if any, are set to the position recommended by the manufacturer;
– in the absence of a clear reason to the contrary, the measurement frequency is 1 000 Hz
(see IEC 60268-1);
– the ambient pressure, relative humidity and ambient temperature are within the limits
given in IEC 60268-1, and shall be stated.
Measurements may be made at a sound pressure of 0,3 Pa if this is necessary due to
limitations of the performance of the loudspeaker or other measurement equipment, and only
if any change in performance between the level used and the reference level is known with
the necessary accuracy for the relevant characteristics.
5 Particular conditions
5.1 Pre-conditioning
A microphone with preamplifier shall be switched on for the period of time specified by the
manufacturer, before measurements are made, to allow the components to reach the
stationary temperature for rated conditions. If the manufacturer specifies no period, a period

SIST EN 60268-4:2
...