IEC 62777:2016

IEC 62777 ®
Edition 1.0 2016-02
INTERNATIONAL
STANDARD
Quality evaluation method for the sound field of directional loudspeaker array
systems
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IEC 62777 ®
Edition 1.0 2016-02
INTERNATIONAL
STANDARD
Quality evaluation method for the sound field of directional loudspeaker array

systems
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.160.50 ISBN 978-2-8322-3136-4

– 2 – IEC 62777:2016  IEC 2016
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references. 6
3 Terms and definitions . 6
4 Personal acoustic zone and sound pressure level . 7
4.1 Personal acoustic zone . 7
4.2 Personal distance between listeners . 8
4.3 Personal distance between a directional loudspeaker array system and a
listener . 8
4.4 Average sound pressure level at a personal acoustic zone . 9
5 Personal acoustic zone index . 9
5.1 General . 9
5.2 PAZI-x . 10
5.3 PAZI-y . 10
5.4 PAZI-xy . 10
5.5 PAZI-xyz . 10
6 Measurement of the sound pressure level for a personal acoustic zone . 10
6.1 General . 10
6.2 Characteristics to be specified . 10
6.3 Method of measurement . 11
6.3.1 Directional loudspeaker array system . 11
6.3.2 Microphone . 11
6.3.3 Test signals . 11
6.3.4 Sound pressure level curves . 11
6.4 Test environment condition . 11
6.4.1 Temperature . 11
6.4.2 Humidity . 11
7 Indication of the characteristics to be specified . 11
Annex A (informative) Example of standard specifications for a personal audio space . 13
Bibliography . 14

Figure 1 – Personal acoustic zone . 8
Figure 2 – Personal acoustic zone and sound pressure level . 8
Figure 3 – Measuring points of the personal acoustic zone . 9

Table 1 – Characteristics to be specified . 12
Table A.1 – Personal acoustic zone – Dimensioned example . 13

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
QUALITY EVALUATION METHOD FOR THE SOUND FIELD
OF DIRECTIONAL LOUDSPEAKER ARRAY SYSTEMS

FOREWORD
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International Standard IEC 62777 has been prepared by subcommittee subcommittee
technical area 11: Quality for audio, video and multimedia systems, of IEC technical
committee technical committee 100: Audio, video and multimedia systems and equipment.
The text of this standard is based on the following documents:
FDIS Report on voting
100/2603/FDIS 100/2637/RVD
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.

– 4 – IEC 62777:2016  IEC 2016
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.
A bilingual version of this publication may be issued at a later date.

INTRODUCTION
Directional loudspeaker array systems provide focused sound for a person to listen alone
without disturbing others. This system is convenient for consumers who want to listen to
sound without earphones or headphones.
This system would be widely used in consumer electronics, for example, smart phone or pad,
TV, computer, navigator, and game machine. The applicable area for the system could be
fitness club, exhibition room, museum, shopping mall, and etc. A simple and easy concept is
needed to evaluate the performance of the directional loudspeaker array system for a
consumer. It will provide consumers with personalized audio space criteria in order to
compare the audio sound field quality between various electronic products that have a
directional loudspeaker array system. It is important to specify the quality evaluation method
for the personal audio space and the concept of personal audio space.
This standard provides guidelines for general test methods to evaluate the quality of
directional loudspeaker array systems.

– 6 – IEC 62777:2016  IEC 2016
QUALITY EVALUATION METHOD FOR THE SOUND FIELD
OF DIRECTIONAL LOUDSPEAKER ARRAY SYSTEMS

1 Scope
This International Standard applies to directional loudspeaker array systems of any kind, and
to the parts of which they are composed or which are used as auxiliaries in such systems.
This standard deals with the determination of the performance of directional loudspeaker
array systems, the comparison of these system types, and the determination of their proper
practical application, by listing the characteristics which are useful for their specification. It
specifies uniform measurement methods for these characteristics.
This standard is restricted to a description of the audio space around a person and the
relevant method of measurement. It does not consider characteristics of loudspeakers, which
are specified in IEC 60268-5.
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.
IEC 60268-1, Sound system equipment – Part 1: General
IEC 60268-2, Sound system equipment
...