ISO/IEC 23091-3:2018/Amd 1:2022

INTERNATIONAL ISO/IEC
STANDARD 23091-3
First edition
2018-04
AMENDMENT 1
2022-04
Information technology — Coding-
independent code points —
Part 3:
Audio
AMENDMENT 1: Headphone support
Reference number
ISO/IEC 23091-3:2018/Amd. 1:2022(E)
© ISO/IEC 2022
ISO/IEC 23091-3:2018/Amd. 1:2022(E)
© ISO/IEC 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
ii
© ISO/IEC 2022 – All rights reserved

ISO/IEC 23091-3:2018/Amd. 1:2022(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
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are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria
needed for the different types of document should be noted. This document was drafted in
accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives or
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rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents) or the IEC
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www.iso.org/iso/foreword.html. In the IEC, see www.iec.ch/understanding-standards.
This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information.
A list of all parts in the ISO/IEC 23091 series can be found on the ISO and IEC websites.
Any feedback or questions on this document should be directed to the user’s national standards
body. A complete listing of these bodies can be found at www.iso.org/members.html and
www.iec.ch/national-committees.
iii
© ISO/IEC 2022 – All rights reserved

ISO/IEC 23091-3:2018/Amd. 1:2022(E)
Information technology — Coding-independent code
points —
Part 3:
Audio
AMENDMENT 1: Headphone support

6.1
Replace Table 2 by:
Table 2 — Definition of loudspeaker index, OutputChannelPosition
Loudspeaker position
Value Loudspeaker position according to Reference [1]
(informative)
Abbr. Name Abbr. Name
0 L Left front FL Front left
1 R Right front FR Front right
2 C Centre front FC Front centre
3 LFE Low frequency enhancement LFE1 Low frequency effects-1
4 Ls Left surround LS Left surround
5 Rs Right surround RS Right surround
6 Lc Left front centre FLc Front left centre
7 Rc Right front centre FRc Front right centre
8 Lsr Rear surround left BL Back left
9 Rsr Rear surround right BR Back right
10 Cs Rear centre BC Back centre
11 Lsd Left surround direct LSd Left surround direct
12 Rsd Right surround direct RSd Right surround direct
13 Lss Left side surround SL Side left
14 Rss Right side surround SR Side right
15 Lw Left wide front FLw Front left wide
16 Rw Right wide front FRw Front right wide
17 Lv Left front vertical height TpFL Top front left
18 Rv Right front vertical height TpFR Top front right
19 Cv Centre front vertical height TpFC Top front centre
20 Lvr Left surround vertical height rear TpBL Top back left
21 Rvr Right surround vertical height rear TpBR Top back right
22 Cvr Centre vertical height rear TpBC Top back centre
a
Audio signals associated with this loudspeaker position are intended for stereo headphone playback only. They can be
unsuitable for loudspeaker playback. This loudspeaker position is applicable for binaural signals but it shall not be applied
for traditional stereo signals.
© ISO/IEC 2022 – All rights reserved

ISO/IEC 23091-3:2018/Amd. 1:2022(E)
Table 2 (continued)
Loudspeaker position
Value Loudspeaker position according to Reference [1]
(informative)
Abbr. Name Abbr. Name
23 Lvss Left vertical height side surround TpSiL Top side left
24 Rvss Right vertical height side surround TpSiR Top side right
25 Ts Top centre surround TpC Top centre
26 LFE2 Low frequency enhancement 2 LFE2 Low frequency effects-2
27 Lb Left front vertical bottom BtFL Bottom front left
28 Rb Right front vertical bottom BtFR Bottom front right
29 Cb Centre front vertical bottom BtFC Bottom front centre
30 Lvs Left vertical height surround TpLS Top left surround
31 Rvs Right vertical height surround TpRS Top right surround
32 Reserved
33 Reserved
34 Reserved
35 Reserved
36 LFE3 Low frequency enhancement 3
37 Leos Left edge of screen
38 Reos Right edge of screen
39 Hwbcal half-way between centre of screen
and left edge of screen
40 Hwbcar half-way between centre of screen
and right edge of screen
41 Lbs Left back surround
42 Rbs Right back surround
a
43 Lear Left ear
a
44 Rear Right ear
45–125 Reserved Reserved
126 Expl Explicit position (see text)
127 Unknown / undefined
a
Audio signals associated with this loudspeaker position are intended for stereo headphone playback only. They can be
unsuitable for loudspeaker playback. This loudspeaker position is applicable for binaural signals but it shall not be applied
for traditional stereo signals.

6.2
Replace:
Range: 0 – 31
by:
Range: 0 – 63
© ISO/IEC 2022 – All rights reserved

ISO/IEC 23091-3:2018/Amd. 1:2022(E)
6.2
Replace Table 3 by:
Table 3 — ChannelConfiguration, loudspeaker layout index, corresponding number of
loudspeakers and their associated positions
"Front/
Informative
Surr. Loudspeaker names in Loudspeaker
Value geometric position Ch. is LFE
LFE" loudspeaker layout abbrev.
a
Azim., Elev.
notation
0 — any setup — — —
1 1/0.0 centre front C 0, 0 0
2 2/0.0 left front, L 30, 0 0
right front R −30, 0
3 3/0.0 centre front, C 0, 0 0
left front, L 30, 0 0
right front R −30, 0 0
4 3/1.0 centre front, C 0, 0 0
left front, L 30, 0 0
right front, R −30, 0 0
rear centre Cs 180, 0 0
5 3/2.0 centre front, C 0, 0 0
left front, L 30, 0 0
right front, R −30, 0 0
left surround, Ls 110, 0 0
right surround Rs −110, 0 0
6 3/2.1 centre front, C 0, 0 0
left front, L 30, 0 0
right front, R −30, 0 0
left surround, Ls 110, 0 0
right surround, Rs −110, 0 0
LFE LFE 0, −15 1
a
"Nominal" positions are as found in typical layout definitions. Tolerances for the angular positions are omitted by
intention as the values vary between various definitions that can be found in relevant industry standard documents. The
azimuth angle is expressed in degrees; positive values rotate to the left when facing the front, i.e. counter clockwise when
looking from above. The elevation angle is expressed in degrees where positive values indicate angles above the horizontal
plane.
b
Audio signals associated with this channel configuration are intended for stereo headphone playback only. They can be
unsuitable for loudspeaker playback. This channel configuration is applicable for binaural signals but it shall not be applied
for traditional stereo signals.
© ISO/IEC 2022 – All rights reserved

ISO/IEC 23091-3:2018/Amd. 1:2022(E)
Table 3 (continued)
"Front/
Informative
Surr. Loudspeaker names in Loudspeaker
Value geometric position Ch. is LFE
LFE" loudspeaker layout abbrev.
a
Azim., Elev.
notation
7 5/2.1 centre front, C 0, 0 0
left front centre, Lc 30, 0 0
right front centre, Rc −30, 0 0
left front, L 45, 0 0
right front, R −45, 0 0
left surround, Ls 110, 0 0
right surround, Rs −110, 0 0
LFE LFE 0, −15 1
8 1+1 channel1 N.A. N.A. 0
channel2 N.A. N.A. 0
9 2/1.0 left front, L 30, 0 0
right front, R −30, 0 0
rear centre Cs 180, 0 0
10 2/2.0 left front, L 30, 0 0
right front, R −30, 0 0
left surround, Ls 110, 0 0
right surround Rs −110, 0 0
11 3/3.1 centre front, C 0, 0 0
left front, L 30, 0 0
right front, R −30, 0 0
left surround, Ls 110, 0 0
right surround, Rs −110, 0 0
rear centre, Cs 180, 0 0
LFE LFE 0, −15 1
12 3/4.1 centre front, C 0, 0 0
left front, L 30, 0 0
right front, R −30, 0 0
left surround, Ls 110, 0 0
right surround, Rs −110, 0 0
rear surround left, Lsr 135, 0 0
rear surround right, Rsr −135, 0 0
LFE LFE 0, −15 1
a
"Nominal" positions are as found in typical layout definitions. Tolerances for the angular positions are omitted by
intention as the values vary between various definitions that can be found in relevant industry standard documents. The
azimuth angle is expressed in degrees; positive values rotate to the left when facing the front, i.e. counter clockwise when
looking from above. The elevation angle is expressed in degrees where positive values indicate angles above the horizontal
plane.
b
Audio signals associated with this channel configuration are intended for stereo headphone playback only. They can be
unsuitable for loudspeaker playback. This channel
...