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IEC 60268-7
Edition 3.0 2020-09
INTERNATIONAL
STANDARD
AMENDMENT 1
Sound system equipment –
Part 7: Headphones and earphones
IEC 60268-7:2010-01/AMD1:2020-09(en)
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IEC 60268-7
Edition 3.0 2020-09
INTERNATIONAL
STANDARD
AMENDMENT 1
Sound system equipment –
Part 7: Headphones and earphones
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.160.50 ISBN 978-2-8322-8763-7
– 2 – IEC 60268-7:2010/AMD1:2020
© IEC 2020
FOREWORD
This amendment has been prepared by technical area 20: Analogue and digital audio, of IEC
technical committee 100: Audio, video and multimedia systems and equipment
The text of this International Standard is based on the following documents:
CDV Rapport de vote
100/3316/CDV 100/3437/RVC
Full information on the voting for the approval of this amendment can be found in the report on
voting indicated in the above table.
The committee has decided that the contents of this amendment and the base publication will
remain unchanged until the stability date indicated on the IEC website 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• withdrawn,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.
_____________
INTRODUCTION to Amendment 1
This Amendment 1 contains the following significant technical changes with respect to
IEC 60268-7:2010:
• evaluation of free-field compensated frequency response has been added;
• evaluation of diffuse-field compensated frequency response has been added;
• the Bibliography has been updated;
• some normative references have been updated;
• the term "HATS" and its definition has been added.
1 Scope
In item a), replace “IEC 60065” with “IEC 62368-1”.
2 Normative references
Add the following new reference:
IEC TS 60318-7, Electroacoustics – Simulators of human head and ear – Part 7: Head and torso
simulator for the measurement of air-conduction hearing aids
IEC:2020
3 Terms and definitions
Add, after the existing term 3.16, the following new term.
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 simulator includes two pinna simulators, and at least one occluded-ear simulator.
[SOURCE: IEC TS 60318-7:2017, 3.1, modified – The preferred term "manikin" has been
omitted.]
Add, after 8.6.6, the following new Subclauses 8.6.7, 8.6.8 and Figure 4.
8.6.7 Free-field compensated frequency response
8.6.7.1 Characteristics to be specified
The frequency response measured at the ear simulator of the HATS is compensated either
during the measurement by inverse filtering with the 0° free-field response of the HATS, or by
subtracting (in dB) the 0° free-field frequency response of the HATS from the uncompensated
measured headphone response at the ear simulator of the HATS as a post-process operation.
8.6.7.2 Method of measurement
• The headphone is brought under standard conditions for measurement, and a test signal at
the rated source voltage is applied in series with the rated source impedance.
• The frequency is then varied over at least the rated frequency range of the headphone (see
8.6.6), and the sound pressure (level) at each frequency is noted for both the right and the
left ear.
NOTE Ideally, the values for both ears are equal. Reasons for differences in practice can include non-
symmetrical positioning of the headphone or wider tolerances of the headphone transducers.
• The output of the ear simulator of the HATS with or without compensation shall be at least
10 dB above the noise floor of the measurement system at all measured frequencies.
The nominal frequency response is obtained from a power average of the five measurements
and finally graphically presented in decibels referred to the value at the standard reference
frequency. The headphones shall be removed and remounted to the HATS before each
measurement.
8.6.7.3 HATS
The HATS used for measurement shall comply with IEC TS 603
...