Apparatus and method for acquiring a plurality of audio signals associated with different sound sources

Patent metadata

Field	Value
Publication number	US-12190899-B2
Application number	US-202217657600-A
Country	US
Kind code	B2
Filing date	Mar 31, 2022
Priority date	Oct 4, 2019
Publication date	Jan 7, 2025
Grant date	Jan 7, 2025

Abstract

Methods, apparatus and techniques for acquiring output signals associated with different sources (such as audio sources) are presented. A first input signal is combined with a delayed and scaled version of a second input signal, to acquire a first output signal. A second input signal is combined with a delayed and scaled version of the first input signal, to acquire a second output signal. Using a random direction optimization, scaling values (forming a candidates' vector) are determined by iteratively modifying the candidates' vector. A Kullback-Leibler divergence is measured. The first output signal and the second output signal are selected to be those measurements associated with the candidate parameters associated with Kullback-Leibler divergence which indicates lowest similarity.

First claim

The invention claimed is:

1. An apparatus for acquiring a plurality of output signals, associated with different sound sources, on the basis of a plurality of input signals, in which signals from the sound sources are combined,
wherein the apparatus is configured to combine a first input signal, or a processed version thereof, with a delayed and scaled version of a second input signal, to acquire a first output signal;
wherein the apparatus is configured to combine a second input signal, or a processed version thereof, with a delayed and scaled version of the first input signal, to acquire a second output signal;
wherein the apparatus is configured to determine, using a random direction optimization:
a first scaling value, which is used to acquire the delayed and scaled version of the first input signal;
a first delay value, which is used to acquire the delayed and scaled version of the first input signal;
a second scaling value, which is used to acquire the delayed and scaled version of the second input signal; and
a second delay value, which is used to acquire the delayed and scaled version of the second input signal,

wherein the random direction optimization is such that candidate parameters form a candidates' vector, the candidates' vector being iteratively refined by modifying the candidates' vector in random directions,
wherein the random direction optimization is such that a metrics indicating the similarity, or dissimilarity, between the first and second output signals is measured, and the first and second output signals are selected to be those measurements associated with the candidate parameters associated with metrics indicating lowest similarity, or highest dissimilarity,
wherein the metrics is processed as a Kullback-Leibler divergence.

2. The apparatus of claim 1 , wherein the delayed and scaled version of the second input signal, to be combined with the first input signal, is acquired by applying a fractional delay to the second input signal.

3. The apparatus of claim 1 , wherein the delayed and scaled version of the first input signal, to be combined with the second input signal, is acquired by applying a fractional delay to the first input signal.

4. The apparatus of claim 1 , wherein the first and second scaling values and first and second delay values are acquired by minimizing an objective function.

5. The apparatus of claim 1 , configured to:
combine the first input signal, or a processed version thereof, with the delayed and scaled version of the second input signal in the time domain and/or in the z transform or frequency domain;
combine the second input signal, or a processed version thereof, with the delayed and scaled version of the first input signal in the time domain and/or in the z transform or frequency domain.

6. The apparatus of claim 1 ,
wherein the optimization is performed in the z transform domain.

7. The apparatus of claim 1 ,
wherein the optimization is performed in the time domain.

8. The apparatus of claim 1 ,
wherein the optimization is performed in the frequency domain.

9. The apparatus of claim 1 , wherein the delay or fractional delay applied to the second input signal is indicative of the relationship and/or difference or arrival between:
the signal from the first source received by the first microphone; and
the signal from the first source received by the second microphone.

10. The apparatus of claim 1 , wherein the delay or fractional delay applied to the first input signal is indicative of the relationship and/or difference or arrival between:
the signal from the second source received by the second microphone; and
the signal from the second source received by the first microphone.

11. The apparatus of claim 1 , wherein the metrics is acquired in form of:

D
KL

⁡

(

P
⁢




⁢
Q

)

=

∑
n

⁢

P
⁡

(
n
)

⁢

log
⁡

(

P
⁡

(
n
)

Q
⁡

(
n
)

)

wherein P (n) is an element associated with the first input signal and Q(n) is an element associated with the second input signal.

12. The apparatus of claim 1 , wherein the metrics is acquired in form of:

D
⁡

(

P
0

,

P
1

)

=

-

∑
n

⁢

[

P
0

⁡

(
n
)

⁢

log
⁡

(

P
0

⁡

(
n
)

P
1

⁡

(

Assignees

• Fraunhofer Ges Forschung
• Univ Ilmenau Tech

Inventors

• Schuller Gerald

Classifications

• G06N7/01

  Probabilistic graphical models, e.g. probabilistic networks · CPC title

• G06N5/01

  Dynamic search techniques; Heuristics; Dynamic trees; Branch-and-bound · CPC title

• H04M3/568

  audio processing specific to telephonic conferencing, e.g. spatial distribution, mixing of participants (echo suppression in two-way loud-speaking telephone systems H04M9/02; sound field processing per se H04S7/30) · CPC title

• G10L21/0272 Primary

  Voice signal separating · CPC title