EN IEC 60268-7:2025

Sound system equipment - Part 7: Headphones and earphones

IEC 60268-7:2025 is applicable to headphones, earphones, headsets and earsets, intended to be used on, or in, the human ear. It also applies to equipment, such as pre-amplifiers, passive networks and power supplies which form an integral part of the headphone system. This document does not deal with: - safety, for which reference is made to IEC 62368-1 or another appropriate standard; - the characteristics of microphones of headsets, for which reference is made to IEC 60268‑4; - earphones and other devices for hearing aids, for which reference is made to IEC 60118-0; - headphones for audiometry; - headphones and other devices which form part of an active ear-defender system, although some of the provisions of this document can be applicable; - active noise cancelation characteristics as covered by IEC 60268-24. This document specifies the characteristics which are included by the manufacturer in specifications, and relevant methods of measurement. It includes a classification of the different types of earphones, mainly characterized by the way in which the transducer is coupled acoustically to the ear, and a classification code which can also be used for marking. Rated conditions and characteristics in this document provided by the manufacturer are not generally intended for external verification. Measurement methods for rated characteristics are informative and are provided for the benefit of manufacturers for the purpose of test repeatability and data comparison. All other specifications and tests are provided for testing by the manufacturer and for external testing and verification. This fourth edition cancels and replaces the third edition published in 2010, and Amendment 1 of 2020. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - consolidated with IEC 60268-7:2010/AMD1:2020; - clause/subclause/annex reconstruction and renumbering; - addition of effective frequency range of the free-field / diffuse-field compensated frequency response; - update of measurement methods of modulation distortion and difference-frequency distortion; - addition of details of two-tone distortion measurements, see Annex I; - addition of details of left-right tracking response for stereo headphones, see Annex J.

Elektroakustische Geräte - Teil 7: Kopfhörer und Ohrhörer

Equipements pour systèmes électroacoustiques - Partie 7: Casques et écouteurs

L'IEC 60268-7:2025 s'applique aux casques, aux écouteurs, aux casques téléphoniques et aux écouteurs téléphoniques destinés à être utilisés sur ou dans l'oreille humaine. Elle s'applique également aux équipements, tels que les préamplificateurs, les réseaux passifs et les alimentations qui font partie intégrante du système de casque. Le présent document ne traite pas: - de la sécurité, pour laquelle il est fait référence à l'IEC 62368-1 ou à une autre norme appropriée; - des caractéristiques des microphones des casques téléphoniques, pour lesquels il est fait référence à l'IEC 60268‑4; - des écouteurs et autres appareils de correction auditive, pour lesquels il est fait référence à l'IEC 60118-0; - des casques d'audiométrie; - des écouteurs et autres appareils qui font partie d'un système de protection auditive, bien que certaines dispositions du présent document puissent être applicables; - des caractéristiques de la suppression active du bruit de fond telles que traitées par l'IEC 60268-24. Le présent document spécifie les caractéristiques incluses par le fabricant dans les spécifications, ainsi que les méthodes de mesure applicables. Elle comprend une classification des différents types d'écouteurs, principalement caractérisés par la façon dont le transducteur est couplé acoustiquement à l'oreille, ainsi qu'un code de classification qui peut également être utilisé pour le marquage. Les caractéristiques et les conditions assignées du présent document fournies par le fabricant ne sont généralement pas destinées à une vérification externe. Les méthodes de mesure des caractéristiques assignées sont informatives et sont fournies dans l'intérêt des fabricants aux fins de répétabilité des essais et de comparaison des données. Toutes les autres spécifications et essais sont fournis pour les essais par le fabricant, ainsi que pour les essais et vérification externes. Cette quatrième édition annule et remplace la troisième édition parue en 2010, et l'Amendement 1 de 2020. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: - consolidée avec l'IEC 60268-7:2010/AMD1:2020; - reconstruction et renumérotation de l'article/du paragraphe/de l'annexe; - ajout de la plage effective de fréquence de la réponse en fréquence compensée en champ libre/diffus; - mise à jour des méthodes de mesurage de la distorsion de modulation et de la distorsion par différence de fréquence; - ajout de détails relatifs aux mesures de distorsion à deux sons, voir Annexe I; - ajout de détails relatifs à la réponse de suivi gauche-droite pour un casque stéréo, voir Annexe J.

Oprema za zvočne sisteme - 7. del: Slušalke in ušesne slušalke (IEC 60268-7:2025)

IEC 60268-7:2025 se uporablja za slušalke, ušesne slušalke, naglavne slušalke in ušesne komplete, namenjene uporabi na ali v človeškem ušesu. Prav tako se uporablja za opremo, kot so predojačevalniki, pasivne mreže in napajalniki, ki so sestavni del sistema slušalk.
Ta dokument ne obravnava:
- varnosti, za katero se sklicuje na IEC 62368-1 ali drug ustrezen standard;
- lastnosti mikrofonov naglavnih slušalk, za katere se sklicuje na IEC 60268-4;
- ušesnih slušalk in drugih naprav za slušne aparate, za katere se sklicuje na IEC 60118-0;
- slušalk za avdiometrijo;
- slušalk in drugih naprav, ki so del aktivnega sistema za zaščito sluha, čeprav so nekatere določbe tega dokumenta lahko uporabne;
- lastnosti aktivnega zmanjševanja hrupa, kot jih pokriva IEC 60268-24.
Ta dokument določa lastnosti, ki jih proizvajalec vključuje v specifikacije, in ustrezne metode merjenja. Vključuje klasifikacijo različnih vrst ušesnih slušalk, ki so predvsem značilne po načinu, kako je pretvornik akustično povezan z ušesom, in klasifikacijsko kodo, ki se lahko uporablja tudi za označevanje. Nazivne pogoje in lastnosti v tem dokumentu, ki jih zagotavlja proizvajalec, na splošno niso namenjene zunanji preveritvi. Metode merjenja za nazivne lastnosti so informativne in so na voljo proizvajalcem za namen ponovljivosti testov in primerjave podatkov. Vse druge specifikacije in testi so namenjeni testiranju s strani proizvajalca in za zunanje testiranje in preverjanje. Ta četrta izdaja razveljavlja in nadomešča tretjo izdajo, objavljeno leta 2010, in Dopolnilo 1 iz leta 2020. Ta izdaja predstavlja tehnično revizijo.
Ta izdaja vključuje naslednje pomembne tehnične spremembe v primerjavi s prejšnjo izdajo:
- združena z IEC 60268-7:2010/AMD1:2020;
- rekonstrukcija in oštevilčenje členov/podčlenov/prilog;
- dodatek učinkovitega frekvenčnega območja kompenzirane frekvenčne odzivnosti prostega polja/razpršenega polja;
- posodobitev metod merjenja modulacijske distorzije in distorzije razlike frekvenc;
- dodatek podrobnosti meritev dvotonske distorzije, glej Prilogo I;
- dodatek podrobnosti sledenja odziva levo-desno za stereo slušalke, glej Prilogo J.

General Information

• Status: Published
• Publication Date: 28-Aug-2025
• ICS: 33.160.50 - Accessories
• Technical Committee: CLC/TC 100X - Audio, video and multimedia systems and equipment and related sub-systems
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 29-Aug-2025
• Due Date: 31-Dec-2024
• Completion Date: 29-Aug-2025
• Ref Project: SIST EN IEC 60268-7:2026 - Sound system equipment - Part 7: Headphones and earphones (IEC 60268-7:2025)

Relations

• Replaces: EN 60268-7:2011 - Sound system equipment - Part 7: Headphones and earphones
• Effective Date: 04-Jul-2023
• Replaces: EN 60268-7:2011/A1:2020 - Sound system equipment - Part 7: Headphones and earphones
• Effective Date: 04-Jul-2023
• Refers: ISO 48-4:2018 - Rubber, vulcanized or thermoplastic — Determination of hardness — Part 4: Indentation hardness by durometer method (Shore hardness)
• Effective Date: 20-Feb-2026
• Refers: EN ISO 3741:2010 - Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Precision methods for reverberation test rooms (ISO 3741:2010)
• Effective Date: 09-Feb-2026
• Refers: EN ISO 266:1997 - Acoustics - Preferred frequencies (ISO 266:1997)
• Effective Date: 09-Feb-2026
• Refers: EN 13293:2002 - Transportable gas cylinders - Specification for the design and construction of refillable transportable seamless normalized carbon manganese steel gas cylinders of water capacity up to 0,5 litre for compressed, liquefied and dissolved gases and up to 1 litre for carbon dioxide
• Effective Date: 09-Feb-2026
• Refers: EN ISO 4869-3:2007 - Acoustics - Hearing protectors - Part 3: Measurement of insertion loss of ear-muff type protectors using an acoustic test fixture (ISO 4869-3:2007)
• Effective Date: 09-Feb-2026
• Refers: EN 60268-12:1995 - Sound system equipment - Part 12: Application of connectors for broadcast and similar use
• Effective Date: 03-Feb-2026
• Refers: EN 60318-4:2010 - Electroacoustics - Simulators of human head and ear - Part 4: Occluded-ear simulator for the measurement of earphones coupled to the ear by means of ear inserts
• Effective Date: 03-Feb-2026
• Refers: EN IEC 60318-7:2022 - Electroacoustics - Simulators of human head and ear - Part 7: Head and torso simulator for the measurement of sound sources close to the ear
• Effective Date: 03-Feb-2026
• Refers: HD 483.11 S3:1993 - Sound system equipment - Part 11: Application of connectors for the interconnection of sound system components
• Effective Date: 03-Feb-2026
• Refers: EN IEC 61987-32:2024 - Industrial-process measurement and control - Data structures and elements in process equipment catalogues - Part 32: Lists of properties (LOP) for I/O modules for electronic data exchange
• Effective Date: 03-Feb-2026
• Refers: HD 483.2 S2:1993 - Sound system equipment - Part 2: Explanation of general terms and calculation methods
• Effective Date: 03-Feb-2026
• Refers: EN IEC 60086-1:2021 - Primary batteries - Part 1: General
• Effective Date: 03-Feb-2026
• Refers: EN 61672-1:2013 - Electroacoustics - Sound level meters - Part 1: Specifications
• Effective Date: 03-Feb-2026

Overview

EN IEC 60268-7:2025 is the internationally recognized standard published by CLC, covering sound system equipment-specifically, headphones, earphones, headsets, and earsets designed to be used on or in the human ear. The standard also applies to associated integral equipment such as pre-amplifiers, passive networks, and power supplies. EN IEC 60268-7:2025 provides definitions, classifications, and requirements for manufacturer specifications and measurement methods, ensuring consistency and comparability across the audio industry.

This fourth edition incorporates the latest advances, amalgamating prior amendments and introducing updates for frequency response, distortion measurements, and stereo headphone tracking. The standard does not address safety (see IEC 62368-1), microphone characteristics (see IEC 60268-4), hearing aids, audiometry headphones, active ear-defenders, or active noise cancellation features.

Key Topics

• Scope and Definitions: Clarifies the types of products covered, from traditional headphones to specialized earsets and the associated electronic components.
• Classification and Coding: Outlines a detailed system for classifying and marking headphone types based on transducer principle, form factor (e.g., circumaural, supra-aural, insert), acoustic coupling, and channel configuration.
• Manufacturer Specifications: Specifies which product characteristics must be declared by manufacturers, such as impedance, frequency response, sound pressure level, and distortion.
• Measurement Methods: Provides repeatable, informative procedures for manufacturers to measure and verify audio characteristics, including:
  • Rated conditions and standard test environments
  • Frequency response mapping (free-field/diffuse-field)
  • Distortion-harmonic, modulation, and difference-frequency
  • Left-right tracking accuracy for stereo headphones
• Marking & User Instructions: Sets requirements for product marking (left/right, channel identification, accessibility) and guidance for safe usage, connector assignments, and interconnections.

Applications

EN IEC 60268-7:2025 is essential in several practical scenarios:

• Product Development: Assists manufacturers in designing new headphone and earphone models by providing a framework for performance characterization and comparison.
• Quality Assurance: Supports standardization of testing procedures, allowing in-house and third-party testing teams to assess audio performance objectively, supporting claims made in product datasheets.
• Regulatory Compliance: Helps manufacturers and suppliers to ensure their headphone products meet recognized international benchmarks, facilitating CE marking and other regional regulatory processes.
• Market Transparency: Enables consumers, retailers, and professionals to compare products on a like-for-like basis using uniform technical specifications and testing results.
• R&D and Innovation: Provides a technical reference for engineers and researchers working on emerging personal audio technologies, ensuring backward compatibility and interoperability.

Related Standards

The following related standards complement EN IEC 60268-7:2025, addressing topics outside its scope or offering supplementary methods:

• IEC 62368-1: Safety requirements for audio/video, information, and communication technology equipment.
• IEC 60268-4: Microphone characteristics and measurement procedures for headsets.
• IEC 60118-0: Hearing aid devices and associated earphones.
• IEC 60268-24: Active noise cancellation device characteristics.
• IEC 60318 series: Simulators for human head and ear (e.g., HATS), used in headphone testing.
• IEC 61672-1: Specifications for sound level meters.
• ISO 266, ISO 3741, ISO 4869-3: Acoustics and noise measurements, including preferred frequencies and hearing protector performance.

Practical Value

Adoption of EN IEC 60268-7:2025 ensures high standards in headphone and earphone design and evaluation, providing clear benefits in product reliability, user safety, and global market acceptance. By standardizing classification, specifications, and measurement procedures, the standard acts as a cornerstone for innovation and quality in the fast-evolving audio equipment industry.

Keywords: EN IEC 60268-7:2025, headphones standard, earphones standard, headphone measurement methods, audio equipment testing, headphone classification, sound system equipment, headphone specifications, headphone industry standards.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2026
Oprema zvokovnega sistema - 7. del: Naglavne in ušesne slušalke (IEC 60268-
7:2025)
Sound system equipment - Part 7: Headphones and earphones (IEC 60268-7:2025)
Elektroakustische Geräte - Teil 7: Kopfhörer und Ohrhörer (IEC 60268-7:2025)
Equipements pour systèmes électroacoustiques - Partie 7: Casques et écouteurs (IEC
60268-7:2025)
Ta slovenski standard je istoveten z: EN IEC 60268-7:2025
ICS:
33.160.50 Pribor Accessories
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60268-7

NORME EUROPÉENNE
EUROPÄISCHE NORM August 2025
ICS 33.160.50 Supersedes EN 60268-7:2011; EN 60268-7:2011/A1:2020
English Version
Sound system equipment - Part 7: Headphones and earphones
(IEC 60268-7:2025)
Equipements pour systèmes électroacoustiques - Partie 7: Elektroakustische Geräte - Teil 7: Kopfhörer und Ohrhörer
Casques et écouteurs (IEC 60268-7:2025)
(IEC 60268-7:2025)
This European Standard was approved by CENELEC on 2025-08-01. 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60268-7:2025 E

European foreword
The text of document 100/4304/FDIS, future edition 4 of IEC 60268-7, prepared by TC 100/Technical
Area 20 "Analogue and digital audio" was submitted to the IEC-CENELEC parallel vote and approved
by CENELEC as EN IEC 60268-7:2025.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2026-08-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2028-08-31
document have to be withdrawn
This document supersedes EN 60268-7:2011 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 60268-7:2025 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 standard indicated:
IEC 60068-1 NOTE Approved as EN 60068-1
IEC 60118-0 NOTE Approved as EN IEC 60118-0
IEC 60268-3 NOTE Approved as EN IEC 60268-3
IEC 60268-4 NOTE Approved as EN IEC 60268-4
IEC 60268-24 NOTE Approved as EN IEC 60268-24
IEC 60318-1 NOTE Approved as EN 60318-1
IEC 61786 (series) NOTE Approved as EN 61786 (series)
IEC 61938 NOTE Approved as EN IEC 61938
IEC 62368-1 NOTE Approved as EN IEC 62368-1
ISO 4869-1 NOTE Approved as EN ISO 4869-1
ISO 7029 NOTE Approved as EN ISO 7029
ISO 18233 NOTE Approved as EN ISO 18233

Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1  Where 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.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60038 - IEC standard voltages EN 60038 -
IEC 60050-801 - International Electrotechnical Vocabulary - - -
Chapter 801: Acoustics and electroacoustics
IEC 60086-1 - Primary batteries - Part 1: General EN IEC 60086-1 -
IEC 60263 - Scales and sizes for plotting frequency EN IEC 60263 -
characteristics and polar diagrams
IEC 60268-1 - Sound system equipment. Part 1: General - -
IEC 60268-2 - Sound system equipment. Part 2: Explanation - -
of general terms and calculation methods
IEC 60268-11 - Sound system equipment. Part 11: Application - -
of connectors for the interconnection of sound
system components
IEC 60268-12 - Sound system equipment. Part 12: Application EN 60268-12 -
of connectors for broadcast and similar use
IEC 60318-4 - Electroacoustics - Simulators of human head EN 60318-4 -
and ear - Part 4: Occluded-ear simulator for
the measurement of earphones coupled to the
ear by means of ear inserts
IEC 60318-7 - Electroacoustics - Simulators of human head EN IEC 60318-7 -
and ear - Part 7: Head and torso simulator for
the measurement of sound sources close to
the ear
IEC 61672-1 - Electroacoustics - Sound level meters - Part 1: EN 61672-1 -
Specifications
ISO 266 1997 Acoustics - Preferred frequencies EN ISO 266 -
ISO 48-4 2018 Rubber, vulcanized or thermoplastic - - -
Determination of hardness - Part 4: Indentation
hardness by durometer method (Shore
hardness)
Publication Year Title EN/HD Year
ISO 3741 - Acoustics - Determination of sound power EN ISO 3741 -
levels and sound energy levels of noise
sources using sound pressure - Precision
methods for reverberation test rooms
ISO 4869-3 - Acoustics - Hearing protectors - Part 3: EN ISO 4869-3 -
Measurement of insertion loss of ear-muff type
protectors using an acoustic test fixture

IEC 60268-7 ®
Edition 4.0 2025-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Sound system equipment –
Part 7: Headphones and earphones

Equipements pour systèmes électroacoustiques –
Partie 7: Casques et écouteurs
ICS 33.160.50  ISBN 978-2-8327-0478-3

IEC 60268-7:2025-06(en-fr)
IEC 60268-7:2025 © IEC 2025
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Classification, designation and coding . 9
5 Marking of terminals, controls and polarity . 13
6 User instructions . 14
7 Conditions for specifications and measurements . 14
7.1 Rated conditions . 14
7.2 Standard conditions for measurement . 15
7.3 Couplers and ear simulators . 15
7.3.1 General . 15
7.3.2 HATS. 16
7.4 Measurement conditions for simulated programme signal . 16
7.5 Loudness comparison conditions . 17
7.5.1 General . 17
7.5.2 Free-field comparison conditions . 17
7.5.3 Diffuse-field comparison conditions . 17
7.6 Ear canal sound pressure level measurement conditions . 17
7.7 Graphical presentation of results . 17
8 Characteristics to be specified and their methods of measurement . 18
8.1 Power supply . 18
8.2 Electrical impedance . 18
8.2.1 Rated impedance . 18
8.2.2 Impedance/frequency characteristic . 18
8.2.3 Rated source impedance . 18
8.3 Input voltage . 19
8.3.1 Rated input voltage . 19
8.3.2 Limiting values of input voltage . 19
8.3.3 Characteristic voltage . 20
8.3.4 Simulated programme signal characteristic voltage . 20
8.3.5 Simulated programme signal characteristic voltage corrected by A-
weighting characteristics and free-field response compensation . 20
8.3.6 Protective devices . 21
8.4 Input power . 22
8.5 Sound pressure (level) . 22
8.5.1 General . 22
8.5.2 Characteristics to be specified . 22
8.5.3 Method of measurement . 23
8.6 Frequency response . 23
8.6.1 Coupler or ear simulator (including HATS) frequency response . 23
8.6.2 Free-field compensated frequency response . 24
8.6.3 Diffuse-field compensated frequency response . 25
8.6.4 Rated frequency range . 26
8.6.5 Effective frequency range of the free-field / diffuse-field compensated
frequency response . 26
8.7 Amplitude non-linearity . 26
IEC 60268-7:2025 © IEC 2025
8.7.1 General . 26
8.7.2 Harmonic distortion . 26
8.7.3 Modulation distortion . 27
8.7.4 Difference-frequency distortion . 28
8.8 Rated environmental conditions . 28
8.9 External electric and/or magnetic field . 29
8.9.1 Characteristics to be specified . 29
8.9.2 Method of measurement . 29
8.10 Unwanted sound radiation. 29
8.10.1 Characteristic to be specified . 29
8.10.2 Method of measurement . 29
8.11 Sound attenuation . 29
8.11.1 Characteristic to be specified . 29
8.11.2 Method of measurement . 30
8.12 Crosstalk attenuation for multi-channel headphones . 30
8.12.1 Characteristic to be specified . 30
8.12.2 Method of measurement . 30
8.13 Application force . 30
8.13.1 Characteristic to be specified . 30
8.13.2 Method of measurement . 30
8.14 Physical characteristics, cables and connectors . 30
9 Classification of characteristics . 30
Annex A (normative) Pinna simulators for measurements of headphones and
earphones . 32
Annex B (normative) Free-field comparison frequency response . 41
B.1 Characteristic to be specified . 41
B.2 Method of measurement (direct) . 41
B.3 Method of measurement (by substitution) . 41
Annex C (normative) Diffuse-field comparison frequency response . 42
C.1 Characteristic to be specified . 42
C.2 Method of measurement (direct) . 42
C.3 Method of measurement (by substitution) . 42
Annex D (normative) Free-field and diffuse-field ear canal sound pressure level
frequency responses . 43
D.1 Characteristic to be specified . 43
D.2 Method of measurement (direct) . 43
D.3 Method of measurement (indirect) . 44
Annex E (normative) Specification and conditions of use of a microphone for use
inside the ear canal . 45
Annex F (informative) Practical details of free-field comparison conditions . 46
Annex G (informative) Practical details of diffuse-field comparison conditions . 47
Annex H (informative) Practical details of the subjective comparison and ear canal
sound pressure level conditions . 48
Annex I (informative) Two-tone distortion measurements . 49
I.1 General . 49
I.2 Difference frequency distortion . 49
I.3 Procedure for measuring difference frequency distortion . 50
I.4 Intermodulation distortion . 52
IEC 60268-7:2025 © IEC 2025
I.5 Procedure for measuring intermodulation distortion . 53
Annex J (informative) Left-right tracking response for stereo headphones . 55
Bibliography . 56

Figure 1 – Diagrammatic horizontal sections showing types of earphones and their
spatial relationships with the pinna and/or canal entrance . 12
Figure 2 – Diagrams showing the four possible constructions: Acoustically open or
closed, and closed- or open-back earphones . 13
Figure 3 – Measurement system using simulated programme signal . 16
Figure 4 – Example of a setup for the measurement of free-field/diffuse-field
compensated frequency response . 25
Figure A.1 – Shape of the recommended pinna simulator . 33
Figure A.2 – Coordinate for the recommended pinna simulator . 34
Figure A.3 – Cross-sectional shapes and dimensions of the recommended pinna
simulator, horizontal section . 37
Figure A.4 – Cross-sectional shapes and dimensions of the recommended pinna
simulator, vertical section . 40
Figure I.1 – Definition of difference frequency distortion products and orders. 50
Figure I.2 – Example of difference frequency distortion of a headphone . 51
Figure I.3 – Example of total difference frequency distortion of a headphone . 52
Figure I.4 – Definition of intermodulation distortion products and orders . 52
Figure I.5 – Example of intermodulation distortion of a headphone . 53
Figure I.6 – Example of total Intermodulation distortion of a headphone . 54
Figure J.1 – Example of a left-right tracking response for a stereo headphone . 55

Table 1 – Classification of characteristics . 31

IEC 60268-7:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Sound system equipment -
Part 7: Headphones and earphones

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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 60268-7 has been prepared by technical area 20: Analog and digital audio, of IEC technical
committee 100: Audio, video and multimedia systems and equipment. It is an International
Standard.
This fourth edition cancels and replaces the third edition published in 2010, and Amendment 1
of 2020. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
• consolidated with IEC 60268-7:2010/AMD1:2020;
• clause/subclause/annex reconstruction and renumbering;
• addition of effective frequency range of the free-field / diffuse-field compensated frequency
response;
IEC 60268-7:2025 © IEC 2025
• update of measurement methods of modulation distortion and difference-frequency
distortion;
• addition of details of two-tone distortion measurements, see Annex I;
• addition of details of left-right tracking response for stereo headphones, see Annex J.
The text of this International Standard is based on the following documents:
Draft Report on voting
100/4303/FDIS 100/4341/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
A list of all parts in the IEC 60268 series, published under the general title Sound system
equipment, can be found on the IEC website.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
IEC 60268-7:2025 © IEC 2025
1 Scope
This part of IEC 60268 is applicable to headphones, earphones, headsets and earsets, intended
to be used on, or in, the human ear. It also applies to equipment, such as pre-amplifiers, passive
networks and power supplies which form an integral part of the headphone system.
This document does not deal with:
a) safety, for which reference is made to IEC 62368-1 or another appropriate standard;
b) the characteristics of microphones of headsets, for which reference is made to IEC 60268-4;
c) earphones and other devices for hearing aids, for which reference is made to IEC 60118-0;
d) headphones for audiometry;
e) headphones and other devices which form part of an active ear-defender system, although
some of the provisions of this document can be applicable;
f) active noise cancelation characteristics as covered by IEC 60268-24.
This document specifies the characteristics which are included by the manufacturer in
specifications, and relevant methods of measurement. It includes a classification of the different
types of earphones, mainly characterized by the way in which the transducer is coupled
acoustically to the ear, and a classification code which can also be used for marking.
Rated conditions and characteristics in this document provided by the manufacturer are not
generally intended for external verification. Measurement methods for rated characteristics are
informative and are provided for the benefit of manufacturers for the purpose of test
repeatability and data comparison. All other specifications and tests are provided for testing by
the manufacturer and for external testing and verification.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60038, IEC standard voltages
IEC 60050-801, International Electrotechnical Vocabulary – Part 801: Acoustics and
electroacoustics, available at https://www.electropedia.org
IEC 60086-1, Primary batteries – Part 1: General
IEC 60263, Scales and sizes for plotting frequency characteristics and polar diagrams
IEC 60268-1, Sound system equipment – Part 1: General
IEC 60268-2, Sound system equipment – Part 2: Explanation of general terms and calculation
methods
IEC 60268-11, Sound system equipment – Part 11: Application of connectors for the
interconnection of sound system components
IEC 60268-12, Sound system equipment – Part 12: Application of connectors for broadcast and
similar use
IEC 60268-7:2025 © IEC 2025
IEC 60318-4, Electroacoustics – Simulators 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 60318-7, Electroacoustics – Simulators of human head and ear – Part 7: Head and torso
simulator for the measurement of sound sources close to the ear
IEC 61672-1, Electroacoustics – Sound level meters – Part 1: Specifications
ISO 266:1997, Acoustics – Preferred frequencies
ISO 48-4:2018, Rubber, vulcanized or thermoplastic – Determination of hardness – Part 4:
Indentation hardness by durometer method (Shore hardness)
ISO 3741, Acoustics – Determination of sound power levels and sound energy levels of noise
sources using sound pressure – Precision methods for reverberation test rooms
ISO 4869-3, Acoustics – Hearing protectors – Part 3: Measurement of insertion loss of ear-muff
type protectors using an acoustic test fixture
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-801 (IEV) and
the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
Any device defined in 3.1 to 3.15 and their connector(s) for electrical input should be regarded
as part of the transducer.
3.1
earphone
electroacoustic transducer intended to be closely coupled to the ear
[SOURCE: IEC 60050-801:1994, 801-27-18, modified – Reference to acoustical oscillations has
been omitted from the definition.]
3.2
headphone
assembly of one or two earphones on a headband
Note 1 to entry: The use of a headband (or chin-band) can be optional, e.g. in the case of intra-concha or insert
devices.
[SOURCE: IEC 60050-801:1994, 801-27-20, modified – Note to entry added.]
3.3
headset
headphones equipped with a microphone
3.4
earset
earphones equipped with a microphone
IEC 60268-7:2025 © IEC 2025
3.5
insert earphone
small earphone that is attached directly to a connecting element, for example an earmould,
inserted into the ear canal
[SOURCE: IEC 60050-801:1994, 801-27-22, modified – Reference to outer ear has been
omitted from the definition.]
3.6
intra-concha earphone
small earphone that fits in the concha cavity, with its acoustic exit close to the entrance of the
ear canal
3.7
supra-aural earphone
earphone applied externally to the outer ear and intended to rest on the pinna
[SOURCE: IEC 60050-801:1994, 801-27-23, modified – The wording "and intended to rest on
the pinna" has been added to the definition.]
3.8
supra-concha earphone
earphone intended to rest on the ridges of the concha cavity
3.9
circumaural earphone
earphone having a cavity large enough to cover the region of the head including the ear
[SOURCE: IEC 60050-801:1994, 801-27-24]
3.10
ear shell
circumaural type of earphone hanging on the ear
3.11
stethoscopic headphone
insert headphone by which the earphone or earphones are coupled to the ears by means of
a pair of rigid tubes, so that the assembly resembles a stethoscope
3.12
acoustically open earphone
earphone which intentionally provides an acoustic path between the external environment and
the ear canal
3.13
acoustically closed earphone
earphone which is intended to prevent acoustic coupling between the external environment
and the ear canal
3.14
closed-back earphone
earphone which does not emit significant sound radiation from the back of the transducer to
the external environment
3.15
open-back earphone
earphone which emits significant sound radiation from the back of the transducer to the external
environment
IEC 60268-7:2025 © IEC 2025
3.16
simulated programme signal
signal whose mean power spectral density closely resembles the average of the mean power
spectral densities of a wide range of programme material, in accordance with IEC 60268-1
Note 1 to entry: This signal is called a "wide band signal" in a few standards.
3.17
head and torso simulator
HATS
simulator of a median adult human head and part of the torso extending in total from the top of
the head to the waist and designed to simulate the sound pick-up characteristics and acoustic
diffraction
Note 1 to entry: The head and torso simulator includes two pinna simulators, and at least one occluded-ear
simulator.
[SOURCE: IEC 60318-7:2022, 3.1, modified – The preferred term "manikin" has been omitted,
and the abbreviated term "HATS" added.]
4 Classification, designation and coding
The following designations and classification codes shall be used:
60268-7 – IEC – XXXX – NNRN – N
where
60268-7-IEC is the standard form of prefix.
• X (first letter) gives the principle of the transducer:
D - electrodynamic (moving coil);
E - electret (self-polarizing);
F - piezoelectric (polymer);
M - electromagnetic (moving armature or diaphragm);
P - piezoelectric (ceramic);
S - electrostatic (externally polarized).
• X (second letter) gives the type of earphone:
C - circumaural;
E - intra-concha;
H - ear shell;
I - insert;
M - supra-concha;
S - supra-aural;
T - stethoscopic.
An illustration of the types of earphones, except "H", is given in Figure 1.
• X (third letter) gives the intended nature of the acoustic coupling to the ear canal:
L - acoustically open (controlled leakage);
S - acoustically closed (minimum leakage).
• X (fourth letter) gives the intended nature of the radiation to the external environment:
C - closed-back (see 3.14);
IEC 60268-7:2025 © IEC 2025
O - open-back (see 3.15).
An illustration of the four possibilities defined in 3.12 to 3.15, and indicated by the third and
fourth classification letters, is given in Figure 2:
• NNRN (first number) gives the impedance in ohms in "mantissa and exponent" form. (For
example, 8 Ω as "08R0", 32 Ω as "32R0" and 600 Ω as "06R2".);
• N (second number) gives the number of channels.
The code, compiled in accordance with the above rules, may be used for marking.
IEC 60268-7:2025 © IEC 2025
NOTE The transducers shown in the schematics are not necessarily positioned in the centre of the housings or concentric to the ear canal.
a) Circumaural, supra-aural and supra-concha type earphone

IEC 60268-7:2025 © IEC 2025
b) Intra-concha, insert and insert with sound tube between transducer and earpiece type earphone
Figure 1 – Diagrammatic horizontal sections showing types of earphones and
their spatial relationships with the pinna and/or canal entrance

IEC 60268-7:2025 © IEC 2025
NOTE 1 Arrows show sound flow or sound leakage.
NOTE 2 The transducers shown in the schematics are not necessarily positioned in the centre of the housings or
concentric to the ear canal.
Figure 2 – Diagrams showing the four possible constructions:
Acoustically open or closed, and closed- or open-back earphones
5 Marking of terminals, controls and polarity
Requirements for marking terminals and controls are given in IEC 60268-1, and for polarity in
IEC 60268-2. In addition, headphones which are intended to be worn with a particular earphone
on each ear shall be marked to indicate the "left" and "right" earphones. If a colour marking is
used, the "right" earphone shall be indicated by a red marking. For the sake of visually-impaired
persons, it is recommended to indicate the left earphone by a projection of at least 1,5 mm
diameter and 0,3 mm to 0,5 mm height.
IEC 60268-7:2025 © IEC 2025
6 User instructions
The user instructions shall include information on:
• connector contact assignments, which shall be as shown in IEC 60268-11;
• controls and switches (if any);
• microphone (if any);
• diagram of the interconnections of the earphones (if more than one);
• classification code (see Clause 4);
• description of the type of headphone.
Information shall also be provided on the safe use of the headphone, using wording similar to
the following:
"To prevent possible hearing damage, do not listen at high volume levels for long periods, do
not use the headphones while driving or cycling, or in any situation where you should be able
to hear other sounds. As a guide to setting the volume level, check that you can still hear your
own voice, when speaking normally while listening with the headphones."
If the headphone is supplied with auxiliary equipment, information shall also be provided on:
• pre-amplifiers and/or passive networks;
• receivers (for cordless systems);
• power supplies;
• other parts, such as magnetic pick-up devices.
7 Conditions for specifications and measurements
7.1 Rated conditions
For an explanation of the meaning of "rated conditions" and "rated value of a characteristic",
reference shall be made to IEC 60268-2.
The rated conditions for a headphone are:
• rated impedance;
• rated input voltage (or power, see 8.4);
• rated noise voltage (or power, see 8.4);
• rated source impedance (see Note to this Subclause 7.1 (below));
• rated frequency range;
• rated long-term maximum input voltage (or power);
• rated maximum permanent noise voltage (or power);
• rated power supply voltage (if any);
• rated climatic conditions (temperature, humidity, air pressure);
• rated damage limited input voltage;
• rated application force.
These values are taken from the manufacturer's specification, and are not subject to
measurement; they constitute the basis for measuring the other characteristics.
IEC 60268-7:2025 © IEC 2025
For climatic conditions, reference is made to IEC 60268-1, and further information is given in
IEC 60068-1 and IEC Guide 106.
NOTE The performance of most types of headphones depends very little on the source impedance. However, in
order to allow headphones of widely different impedances to be reasonably well-matched, in terms of the sound
pressure level produced, to a single headphone output on other equipment, IEC 61938:2018 specifies a source
impedance of 120 Ω, intermediate between the lowest and highest likely impedances of available headphones.
7.2 Standard conditions for measurement
A headphone is working under standard conditions for measurement when all of the following
conditions in a) and b) are fulfilled.
a) At least one earphone is applied to the appropriate coupler or ear simulator, with the rated
application force.
b) A sinusoidal voltage at the standard measuring frequency is applied, in series with the rated
source impedance. The voltage shall be such that a sound pressure level of 94 dB
(reference 20 µPa) is generated in the coupler or ear simulator. Unless otherwise specified
by the manufacturer, the standard measuring frequency shall be 500 Hz. The input signal
shall be applied at the point where the signal from an amplifier or other equipment is applied
when the headphone is in use. This point may be the input of a piece of auxiliary equipment,
such as a preamplifier.
As an alternative, the manufacturer may specify this condition as being a signal voltage
which dissipates a power of 1 mW in a pure resistance equal to the rated impedance of the
earphone being measured. The output impedance of the amplifier used for headphones
measurement shall be 2 Ω or less in order to keep the output voltage constant.
NOTE Electrostatic, piezoelectric, electret condenser and cordless headphones are within the scope of this
document. The signal can be sent to the headphone by infra-red, radio, light or magnetic induction (either directly
to the transducers or to a magnetic pick-up device and amplifier). These types of headphone are more easily
dealt with by specifying the sound pressure level to be generated (the input signal being applied to the transmitter
unit), rather than by specifying the power in the rated impedance.
c) Unless otherwise specified by the manufacturer, volume controls are set at minimum
attenuation. For headphones supplied with a preamplifier, and for cordless headphones, the
manufacturer shall specify a reference position of the gain control for use in measurements.
Other controls shall be set at the designated "normal" positions, or at stated positions. The
stated positions should preferably give the greatest range of frequency response. Balance
controls shall be set for equal voltages at the terminals of the channels. Crosstalk controls
shall be set for minimum crosstalk.
d) If the headphone requires a power supply, the rated supply voltage and frequency are
applied.
7.3 Couplers and ear simulators
7.3.1 General
The manufacturer should use the coupler or ear simulator which is specified in the International
Standard for the measurement of the headphone or earphone, for which the manufacturer is
publishing results. The manufacturer shall state the type of coupler, ear simulator, or HATS
used in the results.
NOTE Examples of the international standards specifying the couplers and ear simulators are IEC 60318-1,
IEC 60318-2, IEC 60318-3, IEC 60318-5, IEC 60318-4, ITU-T Recommendation P.57, 4.3 and the ear part of HATS
(head and torso simulator) in IEC 60318-7.
If a different coupler or ear simulator not specified in the international standards listed in the
abovementioned note was used, the manufacturer shall state its physical parameters, shape,
dimension, volume of the cavity, etc., to maintain repeatability of measurement.
IEC 60268-7:2025 © IEC 2025
7.3.2 HATS
The HATS used for measurement shall comply with IEC 60318-7. The pinna simulator specified
in Annex A i
...