Blind source separation method and acoustic signal processing system for improving interference estimation in binaural wiener filtering

• US 8,290,189 B2
• Filed: 01/21/2010
• Issued: 10/16/2012
• Est. Priority Date: 01/21/2009
• Status: Expired due to Fees

• Current Assignee: Sivantos Pte. Ltd. (WS Audiology A/S)
• Original Assignee: Siemens AG
• Inventors: Kellermann, Walter, Zheng, Yuanhang
• Primary Examiner(s): Goins, Davetta W
• Assistant Examiner(s): DABNEY, PHYLESHA LARVINIA
• Application Number:
  US12/691,015
• Publication Number:
  US 20100183178A1
• Time in Patent Office: 999 Days
• Field of Search: 381/312, 381/317, 381/318, 381/320, 381/321, 381/71.1, 381/71.11, 381/91, 381/94.1
• US Class Current: 381/317
• CPC Class Codes: G10L 21/0272 Voice signal separating
• CPC Class Codes: H04R 2225/41 Detection or adaptation of hearing aid parameters or programs to listening situation, e.g. pub, forest
• CPC Class Codes: H04R 25/407 Circuits for combining signals of a plurality of transducers
• CPC Class Codes: H04R 25/552 Binaural

Abstract

A method and an acoustic signal processing system for noise reduction of a binaural microphone signal (x₁, x₂) with one target point source and M interfering point sources (n₁, n₂, . . . , n_M) as input sources to a left and a right microphone of a binaural microphone system, include:

• • filtering a left and a right microphone signal by a Wiener filter to obtain binaural output signals of a target point source, where the Wiener filter is calculated as:

$H_W=1-\frac{{\Phi }_{\left(x_{1,n}+x_{2,n}\right)\left(x_{1,n}+x_{2,n}\right)}}{{\Phi }_{\left(x_1+x_2\right)\left(x_1+x_2\right)}},$
where H_W is the Wiener filter, Φ_{(x1,n+x2,n)(x1,n+x2,n)} is the auto power spectral density of the sum of all of the M interfering point sources components (x1,n, x2,n) contained in the left and right microphone signals and Φ_{(x1+x2)(x1+x2)} is the auto power spectral density of the sum of the left and right microphone signals. Due to the linear-phase property of the calculated Wiener filter, original binaural cues are perfectly preserved not only for the target source but also for the residual interfering sources.

Claims

1. A method for noise reduction of a binaural microphone signal (x₁, x₂) with one target point source and M interfering point sources (n₁, n₂, . . . , n_M) as input sources to a left and a right microphone of a binaural microphone system, the method comprising the following step:

filtering a left and a right microphone signal (x₁, x₂) by a Wiener filter to obtain binaural output signals (ŝ

_L,ŝ

_R) of the target point source, where the Wiener filter is calculated as;

2. The method according to claim 1, which further comprises approximating the sum of all of the M interfering point sources components (x_1,n, x_2,n) contained in the left and right microphone signals (x₁, x₂) by an output (y₁) of a blind source separation with the left and right microphone signals (x₁, x₂) as input signals.

3. The method according to claim 2, wherein the blind source separation includes a directional blind source separation algorithm and a shadow blind source separation algorithm.

4. An acoustic signal processing system, comprising:

a binaural microphone system with a left microphone having a left microphone signal (x₁) and a right microphone having a right microphone signal (x₂); and

a Wiener filter unit for noise reduction of a binaural microphone signal (x₁, x₂) with one target point source and M interfering point sources (n₁, n₂, . . . , n_M) as input sources to said left and said right microphones;

said Wiener filter unit having an algorithm calculated as;

5. The acoustic signal processing system according to claim 4, which further comprises a blind source separation unit having an output (y₁), the sum of all of the M interfering point sources components (x_1,n, x_2,n) contained in the left and right microphone signals (x₁, x₂) being approximated by the output (y₁) of said blind source separation unit with the left and right microphone signals (x₁, x₂) as input signals.

6. The acoustic signal processing system according to claim 5, wherein said blind source separation unit includes a directional blind source separation unit and a shadow blind source separation unit.

7. The acoustic signal processing system according to claim 4, wherein said left and right microphones are located in different hearing aids.

8. The acoustic signal processing system according to claim 5, wherein said left and right microphones are located in different hearing aids.

9. The acoustic signal processing system according to claim 6, wherein said left and right microphones are located in different hearing aids.