Signal processing apparatus for enhancing a voice component within a multi-channel audio signal

Patent metadata

Field	Value
Publication number	US-10210883-B2
Application number	US-201715428723-A
Country	US
Kind code	B2
Filing date	Feb 9, 2017
Priority date	Dec 12, 2014
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

A signal processing apparatus for enhancing a voice component within a multi-channel audio signal comprising a left channel audio signal, a center channel audio signal, and a right channel audio signal, the signal processing apparatus comprising a filter and a combiner; wherein the filter is configured to determine an overall magnitude of the multi-channel audio signal over frequency based on the multi-channel audio signal, to obtain a gain function based on a ratio between a magnitude of the center channel audio signal and the overall magnitude of the multi-channel audio signal, and to weight the left channel audio signal, the center channel audio signal, and the right channel audio signal by the gain function; and wherein the combiner is configured to combine individually the left channel audio signal, the center channel audio signal, and the right channel audio signal with the weighted right channel audio signal.

First claim

What is claimed is:

1. A signal processing apparatus for enhancing a voice component within a multi-channel audio signal, the multi-channel audio signal comprising a left channel audio signal (L), a center channel audio signal (C), and a right channel audio signal (R), the signal processing apparatus comprising:
a filter configured to:
determine a measure representing an overall magnitude of the multi-channel audio signal over frequency based on the left channel audio signal (L), the center channel audio signal (C), and the right channel audio signal (R),
obtain a gain function (G) based on a ratio between a measure of magnitude of the center channel audio signal (C) and the measure representing the overall magnitude of the multi-channel audio signal, wherein the gain function is frequency dependent,
weight the left channel audio signal (L) by the gain function (G) to obtain a weighted left channel audio signal (L E ),
weight the center channel audio signal (C) by the gain function (G) to obtain a weighted center channel audio signal (C E ), and
weight the right channel audio signal (R) by the gain function (G) to obtain a weighted right channel audio signal (R E ); and

a combiner configured to:
combine the left channel audio signal (L) with the weighted left channel audio signal (L E ) to obtain a combined left channel audio signal (L EV ),
combine the center channel audio signal (C) with the weighted center channel audio signal (C E ) to obtain a combined center channel audio signal (C EV ), and
combine the right channel audio signal (R) with the weighted right channel audio signal (R E ) to obtain a combined right channel audio signal (R EV ).

2. The signal processing apparatus of claim 1 , wherein the filter is further configured to determine the measure representing the overall magnitude of the multi-channel audio signal as a sum of the measure of magnitude of the center channel audio signal (C) and a measure of magnitude of a difference of the left channel audio signal (L) and the right channel audio signal (R).

3. The signal processing apparatus of claim 1 , wherein the filter is configured to determine the gain function (G) according to the following equations:

G
⁡

(

m
,
k

)

=

P
C

⁡

(

m
,
k

)

P
C

⁡

(

m
,
k

)

+

P
S

⁡

(

m
,
k

)

P
C

⁡

(

m
,
k

)

=



C
⁡

(

m
,
k

)



2

P
S

⁡

(

m
,
k

)

=



L
⁡

(

m
,
k

)

-

R
⁡

(

m
,
k

)



2

wherein G denotes the gain function, L denotes the left channel audio signal, C denotes the center channel audio signal, R denotes the right channel audio signal, P C denotes a power of the center channel audio signal (C) as the measure representing a magnitude of the center channel audio signal (C), P S denotes a power of a difference between the left channel audio signal (L) and the right channel audio signal (R), and the sum of P C and P S denotes the measure representing the overall magnitude of the multi-channel audio signal, m denotes a sample time index, and k denotes a frequency bin index.

4. The signal processing apparatus of claim 1 , wherein the multi-channel audio signal further comprises a left surround channel audio signal (LS) and a right surround channel audio signal (RS),
wherein the filter is further configured to:
determine the measure representing the overall magnitude of the multi-channel audio signal over frequency additionally based on the left surround channel audio signal (LS) and the right surround channel audio signal (RS), and
determine the measure representing the overall magnitude of the multi-channel audio signal as the sum of the measure of magnitude of the center channel audio signal (C), of a measure of magnitude of a difference of the left channel audio signal (L) and the right channel audio signal (R), and of a measure of magnitude of a difference of the left surround channel audio signal (LS) and the right surround channel audio signal (RS).

5. The signal processing apparatus of claim 1 , further comprising:
a voice activity detector configured to determine a voice activity indicator (V) based on the left channel audio signal (L), the center channel audio signal (C), and the right channel audio signal (R), the voice activity indicator (V) indicating a magnitude of the voice component within the multi-channel audio signal over time,

Assignees

• Huawei Tech Co Ltd

Inventors

• Geiger Juergen
• Grosche Peter

Classifications

• G10L21/0316 Primary

  by changing the amplitude · CPC title

• G10L21/0272

  Voice signal separating · CPC title

• H04S5/00

  Pseudo-stereo systems, e.g. in which additional channel signals are derived from monophonic signals by means of phase shifting, time delay or reverberation · CPC title

• H04S3/008

  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 G10L19/02) · CPC title