Apparatus and method for enhancing a spatial perception of an audio signal

Patent metadata

Field	Value
Publication number	US-9877131-B2
Application number	US-201615177994-A
Country	US
Kind code	B2
Filing date	Jun 9, 2016
Priority date	Dec 9, 2013
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

An apparatus and a method for enhancing a spatial perception of an audio signal are provided creating increased interaural-level differences. To obtain this effect, two dipoles are used: one for producing a left audio signal and one for producing a right audio signal.

First claim

What is claimed is:

1. An apparatus for enhancing a spatial perception of a two-channel audio signal comprising a first audio channel signal and a second audio channel signal, the apparatus comprising:
a dipole steering unit, comprising:
a filter bank configured to separate each of the first audio channel signal and the second audio channel signal into at least a low frequency subband component, a mid frequency subband component and a high frequency subband component;
a first dipole steering module configured to receive and process the mid frequency component of the first audio channel signal and to produce a first dipole signal based on the first audio channel signal;
a second dipole steering module configured to receive and process the mid frequency component of the second audio channel signal and to produce a second dipole signal based on the second audio channel signal;
a first summation amplifier configured to receive and sum the mid frequency component of the first audio channel signal from the first dipole steering module and the low frequency component and the high frequency component of the first audio channel signal from the filter bank, and to output the summed signal as a first transducer driving signal; and
a second summation amplifier configured to receive and sum the mid frequency component of the second audio channel signal from the second dipole steering module and the low frequency component and the high frequency component of the first audio channel signal from the filter bank, and to output the summed signal as a second transducer driving signal;

wherein the first dipole steering module and the second dipole steering module are configured to produce the first dipole signal and the second dipole signal such that, when output via a transducer unit which comprises at least one pair of transducers, a first zero sound propagation direction of the first dipole signal has a positive azimuth angle with regard to a steering reference direction, and a second zero sound propagation direction of the second dipole signal has a negative azimuth angle with regard to the steering reference direction.

2. The apparatus according to claim 1 , wherein the first dipole steering module and the second dipole steering module are configured to further produce the first dipole signal and the second dipole signal such that, when output via the transducer unit, a first main sound propagation direction of the first dipole signal has a negative azimuth angle with regard to the steering reference direction, and a second main sound propagation direction of the second dipole signal has a positive azimuth angle with regard to the steering reference direction.

3. The apparatus according to claim 1 , wherein:
the first audio channel signal is a left audio channel signal and the second audio channel signal is a right audio channel signal; and
the first dipole steering module and the second dipole steering module are configured to further produce the first dipole signal and the second dipole signal such that, when the steering reference direction points towards a user facing the transducer unit, the first zero propagation direction points towards the right ear of the user, and the second propagation direction points towards the left ear of the user.

4. The apparatus according to claim 1 , wherein the transducer unit comprises:
a first pair of transducers configured to emit the first dipole signal; and
a second pair of transducers configured to emit the second dipole signal, wherein the first pair of transducers and the second pair of transducers are located in a fixed position with respect to each other.

5. The apparatus according to claim 4 , wherein the first pair of transducers and the second pair of transducers are spaced by a distance of less than 40 cm.

6. The apparatus according to claim 1 , wherein the first dipole steering module and the second dipole steering module are configured to produce the first dipole signal and the second dipole signal such that, when output via the transducer unit, perceivable interaural-level differences in a sound field are generated by the transducer unit.

7. The apparatus according to claim 1 , wherein the transducer unit comprises only one pair of transducers, and wherein the transducer unit is connected to the dipole steering module such that the transducer unit is configured to emit the first dipole signal and the second dipole signal.

8. The apparatus according to claim 1 , wherein each of the first dipole signal and the second dipole signal comprises a first signal component and a second signal component which are different with respect to sign and phase.

9. The apparatus according to claim 8 , wherein the dipole steering unit is configured to adapt the first audio channel signal and the second audio channel signal such that a difference in phase between the first signal component and the second signal component is obtained by delaying the first signal component or the second signal component.

10. The apparatus according to claim 8 , wherein the dipole steering unit is configured to adapt the first audio channel signal and the second audio channel signal such that a difference in sign between the first signal component and the second signal component is obtained by inverting the first signal component or the second signal component.

11. A device comprising:
at least one pair of speakers; and
an apparatus configured to enhance a spatial perception of a two-channel audio signal comprising a first audio channel signal and a second audio channel signal, the apparatus comprising:
a dipole steering unit, comprising:
a filter bank configured to separate each of the first audio channel signal and the second audio channel signal into at least a low frequency subband component, a mid frequency subband component and a high frequency subband component;
a first dipole steering module configured to receive and process the mid frequency component of the first audio channel signal and to produce a first dipole signal based on the first audio channel signal;
a second dipole steering module configured to receive and process the mid frequency component of the second audio channel signal and to produce a second dipole signal based on the second audio channel signal;
a first summation amplifier configured to receive and sum the mid frequency component of the first audio channel signal from the first dipole steering module and the low frequency component and the high frequency component of the first audio channel signal from the filter bank, and to output the summed signal as a first transducer driving signal; and
a second summation amplifier configured to receive and sum the mid frequency component of the second audio channel signal from the second dipole steering module and the low frequency component and the high frequency component of the first audio channel signal from the filter bank, and to output the summed signal as a second transducer driving signal;

wherein the first dipole steering module and the second dipole steering module are configured to produce the first dipole signal and the second dipole signal such that, when output via a transducer unit which comprises at least one pair of transducers, a first zero sound propagation direction of the first dipole signal has a positive azimuth angle with regard to a steering reference direction, and a second zero sound propagation direction of the second dipole signal has a negative azimuth angle with regard to the steering reference direction; and
wherein the at least one pair of transducers is associated with the at least one pair of speakers.

12. The device according to claim 11 wherein the device

Assignees

• Huawei Tech Co Ltd

Inventors

• Grosche Peter
• Lang Yue

Classifications

• H04S1/007 Primary

  in which the audio signals are in digital form (data reduction aspects thereof based on psychoacoustics G10L19/02) · CPC title

• H04R5/02 Primary

  Spatial or constructional arrangements of loudspeakers · CPC title

• H04R5/04

  Circuit arrangements, {e.g. for selective connection of amplifier inputs/outputs to loudspeakers, for loudspeaker detection, or for adaptation of settings to personal preferences or hearing impairments (combinations of amplifiers H03F3/68; stereophonic systems H04S)} · CPC title

• H04R2499/11

  Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's · CPC title

• H04R2203/12

  Beamforming aspects for stereophonic sound reproduction with loudspeaker arrays · CPC title