1. CPC Sections
  2. CPC Section H
  3. CPC Class H04
  4. CPC Subclass H04S
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CPC
COOPERATIVE PATENT CLASSIFICATION
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H04S
STEREOPHONIC SYSTEMS  [2018-08]
NOTES

  • In this subclass, the following term is used with the meaning indicated:
    • "stereophonic systems" covers quadraphonic or similar systems
  • In this subclass, it is desirable to add the indexing codes of H04S 2400/00 and H04S 2420/00.
WARNING

  • In this subclass non-limiting references (in the sense of paragraph 39 of the Guide to the IPC) may still be displayed in the scheme.
H04S 1/00
Two-channel systems (H04S 5/00, H04S 7/00 take precedence) [2013-01]
H04S 1/002
.
{Non-adaptive circuits, e.g. manually adjustable or static, for enhancing the sound image or the spatial distribution (control circuits for electronic adaptation of the sound field H04S 7/30)} [2013-01]
H04S 1/005
. .
{For headphones} [2013-01]
H04S 1/007
.
{in which the audio signals are in digital form (data reduction aspects thereof based on psychoacoustics G10L 19/02)} [2013-01]
H04S 3/00
Systems employing more than two channels, e.g. quadraphonic (H04S 5/00, H04S 7/00 take precedence) [2013-01]
H04S 3/002
.
{Non-adaptive circuits, e.g. manually adjustable or static, for enhancing the sound image or the spatial distribution (control circuits for electronic adaptation of the sound field H04S 7/30)} [2013-01]
H04S 3/004
. .
{For headphones} [2013-01]
H04S 3/006
.
{in which a plurality of audio signals are transformed in a combination of audio signals and modulated signals, e.g. CD-4 systems} [2020-05]
H04S 3/008
.
{in which the audio signals are in digital form, i.e. employing more than two discrete digital channels (data reduction aspects thereof based on psychoacoustics G10L 19/02)} [2020-05]
H04S 3/02
.
of the matrix type, i.e. in which input signals are combined algebraically, e.g. after having been phase shifted with respect to each other [2013-01]
H04S 5/00
Pseudo-stereo systems, e.g. in which additional channel signals are derived from monophonic signals by means of phase shifting, time delay or reverberation  [2018-05]
H04S 5/005
.
{of the pseudo five- or more-channel type, e.g. virtual surround} [2013-01]
H04S 5/02
.
of the pseudo four-channel type, e.g. in which rear channel signals are derived from two-channel stereo signals [2013-01]
H04S 7/00
Indicating arrangements; Control arrangements, e.g. balance control [2015-10]
H04S 7/30
.
{Control circuits for electronic adaptation of the sound field} [2020-05]
H04S 7/301
. .
{Automatic calibration of stereophonic sound system, e.g. with test microphone} [2013-01]
H04S 7/302
. .
{Electronic adaptation of stereophonic sound system to listener position or orientation (H04S 7/301 takes precedence)} [2013-01]
H04S 7/303
. . .
{Tracking of listener position or orientation} [2013-01]
H04S 7/304
. . . .
{For headphones} [2013-01]
H04S 7/305
. .
{Electronic adaptation of stereophonic audio signals to reverberation of the listening space (H04S 7/301 takes precedence)} [2020-05]
H04S 7/306
. . .
{For headphones} [2013-01]
H04S 7/307
. .
{Frequency adjustment, e.g. tone control (H04S 7/301 takes precedence)} [2020-05]
H04S 7/308
. .
{Electronic adaptation dependent on speaker or headphone connection} [2013-01]
H04S 7/40
.
{Visual indication of stereophonic sound image} [2020-05]
H04S 2400/00
Details of stereophonic systems covered by H04S but not provided for in its groups [2019-05]
H04S 2400/01
.
Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved [2013-01]
H04S 2400/03
.
Aspects of down-mixing multi-channel audio to configurations with lower numbers of playback channels, e.g. 7.1 -> 5.1 (H04S 2400/01 takes precedence) [2013-01]
H04S 2400/05
.
Generation or adaptation of centre channel in multi-channel audio systems [2013-01]
H04S 2400/07
.
Generation or adaptation of the Low Frequency Effect [LFE] channel, e.g. distribution or signal processing [2013-01]
H04S 2400/09
.
Electronic reduction of distortion of stereophonic sound systems [2013-01]
H04S 2400/11
.
Positioning of individual sound objects, e.g. moving airplane, within a sound field (H04S 2420/13 takes precedence) [2013-01]
H04S 2400/13
.
Aspects of volume control, not necessarily automatic, in stereophonic sound systems [2013-01]
H04S 2400/15
.
Aspects of sound capture and related signal processing for recording or reproduction [2013-01]
H04S 2420/00
Techniques used stereophonic systems covered by H04S but not provided for in its groups [2019-05]
H04S 2420/01
.
Enhancing the perception of the sound image or of the spatial distribution using head related transfer functions [HRTF's] or equivalents thereof, e.g. interaural time difference [ITD] or interaural level difference [ILD] [2013-01]
H04S 2420/03
.
Application of parametric coding in stereophonic audio systems [2013-01]
H04S 2420/05
.
Application of the precedence or Haas effect, i.e. the effect of first wavefront, in order to improve sound-source localisation [2013-01]
H04S 2420/07
.
Synergistic effects of band splitting and sub-band processing [2013-01]
H04S 2420/11
.
Application of ambisonics in stereophonic audio systems [2013-01]
H04S 2420/13
.
Application of wave-field synthesis in stereophonic audio systems [2013-01]