Speech enhancement using multiple microphones on multiple devices

Patent metadata

Field	Value
Publication number	US-9113240-B2
Application number	US-40505709-A
Country	US
Kind code	B2
Filing date	Mar 16, 2009
Priority date	Mar 18, 2008
Publication date	Aug 18, 2015
Grant date	Aug 18, 2015

Abstract

Signal processing solutions take advantage of microphones located on different devices and improve the quality of transmitted voice signals in a communication system. With usage of various devices such as Bluetooth headsets, wired headsets and the like in conjunction with mobile handsets, multiple microphones located on different devices are exploited for improving performance and/or voice quality in a communication system. Audio signals are recorded by microphones on different devices and processed to produce various benefits, such as improved voice quality, background noise reduction, voice activity detection and the like.

First claim

What is claimed is:

1. A method of processing audio signals comprising:
capturing a first audio signal, representing sound from a plurality of sound sources, with a first microphone located on a first device that includes a first communication interface configured to exchange wireless signals with a second device over a communication link;
receiving a second audio signal from a second microphone located on the second device
selecting a source separating algorithm from a plurality of source separating algorithms, the selection being based on range information indicating a distance between the first microphone and the second microphone; and
processing the first and second captured audio signals according to the selected source separating algorithm to produce a signal representing sound from one of the sound sources separated from sound from others of the sound sources.

2. The method of claim 1 , wherein the second device is a wireless headset in communication with the first device over the communication link.

3. The method of claim 2 , wherein the communication link is a wireless link that uses a Bluetooth protocol.

4. The method of claim 3 , wherein the range information is provided by the Bluetooth protocol.

5. The method of claim 1 , wherein processing includes
selecting the sound source separating algorithm from a blind source separation algorithm, beamforming algorithm or spatial diversity algorithm, wherein range information is used by the selected source separating algorithm.

6. The method of claim 1 , further comprising:
performing voice activity detection based on the signal.

7. The method of claim 1 , further comprising:
cross-correlating the first and second audio signals; and
estimating a delay between the first and second audio signals based on the cross-correlation between the first and second audio signals.

8. The method of claim 7 , further comprising low pass filtering the first and second audio signals prior to performing the cross-correlation of the first and second audio signals.

9. The method of claim 1 , further comprising:
compensating for a delay between the first and second audio signals.

10. The method of claim 1 , further comprising:
compensating for different audio sampling rates of the first and second audio signals.

11. An apparatus, comprising:
a first microphone, a first communication interface configured to exchange wireless signals with a separate device; and
one or more processors configured to:
receive a second audio signal, representing sound from the sound sources, from a second microphone located on the separate device,
select a source separating algorithm from a plurality of source separating algorithms, the selection being based on range information indicating a distance between the first microphone and the second microphone, and
process the first and second audio signals according to the selected source separating algorithm to produce a signal representing sound from one of the sound sources separated from sound from others of the sources.

12. The apparatus of claim 11 , wherein the separate device is a wireless headset.

13. The apparatus of claim 12 , wherein the communication link is a wireless link that uses a Bluetooth protocol.

14. The apparatus of claim 13 , wherein the range information is provided by the Bluetooth protocol.

15. The apparatus of claim 11 , wherein the processor selects the sound source separating algorithm from a blind source separation algorithm, beamforming algorithm or spatial diversity algorithm.

16. The apparatus of claim 11 , further comprising:
a voice activity detector responsive to the signal.

17. An apparatus, comprising:
means for capturing a first audio signal
means for exchanging wireless signals with a separate device;
means for receiving a second audio signal, representing sound from the sound sources, from the second device
means for selecting a source separating algorithm from a plurality of source separating algorithms, the selection being based on range information indicating a distance between the first microphone and the second microphone; and
means for processing the first and second captured audio signals according to the selected source separating algorithm to produce a signal representing sound from one of the sound sources separated from sound from others of the sound sources.

18. The apparatus of claim 17 , wherein the separate device is a wireless headset communicating with the apparatus by way of the means for exchanging.

19. The apparatus of claim 18 , wherein the means for exchanging uses a Bluetooth protocol.

20. The apparatus of claim 19 , wherein the range information is provided by the Bluetooth protocol.

21. The apparatus of claim 17 , further comprising:
means for selecting the sound source separating algorithm from a blind source separation algorithm, beamforming algorithm or spatial diversity algorithm.

22. A non-transitory computer-readable medium embodying a set of instructions executable by one or more processors, comprising:
code for capturing a first audio signal, representing sound from a plurality of sound sources, at a first device that includes a first communication interface configured to exchange wireless signals with a separate device;
code for receiving a second audio signal from the second device;
code for selecting a source separating algorithm from a plurality of source separating algorithms, the selection being based on range information indicating a distance between the first microphone and the second microphone; and
code for processing the first and second captured audio signals according to the selected source separating algorithm to produce a signal representing sound from one of the sound sources separated from sound from others of the sound sources.

23. The computer-readable medium of claim 22 , further comprising:
code for performing voice activity detection based on the signal.

24. The computer-readable medium of claim 22 , further comprising:
code for cross-correlating the first and second audio signals; and
code for estimating a delay between the first and second audio signals based on the cross-correlation between the first and second audio signals.

25. The computer-readable medium of claim 24 , further comprising code for low pass filtering the first and second audio signals prior to prior to performing the cross-correlation of the first and second audio signals.

26. The computer-readable medium of claim 22 , further comprising:
code for compensating for a delay between the first and second audio signals.

27. The computer-readable medium of claim 22 , further comprising:
code for compensating for different audio sampling rates of the first and second audio signals.

28. The method of claim 1 , wherein the first device is a wireless device.

29. The apparatus of claim 11 , wherein the apparatus is a wireless device.

30. The apparatus of claim 17 , wherein the apparatus is a wireless device.

31. The computer-readable medium of claim 24 , wherein the first device is a wireless device.

Assignees

• Ramakrishnan Dinesh
• Wang Song
• Qualcomm Inc

Inventors

• Ramakrishnan Dinesh
• Wang Song

Classifications

• H04R2499/11

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

• G10L21/0308

  characterised by the type of parameter measurement, e.g. correlation techniques, zero crossing techniques or predictive techniques · CPC title

• G10L21/028

  using properties of sound source · CPC title

• H04R2430/20

  Processing of the output signals of the acoustic transducers of an array for obtaining a desired directivity characteristic (H04R2203/12 takes precedence) · CPC title

• G10L2021/02165

  Two microphones, one receiving mainly the noise signal and the other one mainly the speech signal · CPC title