Systems and methods for surround sound echo reduction

Patent metadata

Field	Value
Publication number	US-9497544-B2
Application number	US-201313933005-A
Country	US
Kind code	B2
Filing date	Jul 1, 2013
Priority date	Jul 2, 2012
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

A method for echo reduction by an electronic device is described. The method includes nulling at least one speaker. The method also includes mixing a set of runtime audio signals based on a set of acoustic paths to determine a reference signal. The method also includes receiving at least one composite audio signal that is based on the set of runtime audio signals. The method further includes reducing echo in the at least one composite audio signal based on the reference signal.

First claim

What is claimed is:

1. A method for echo reduction by an electronic device, comprising:
mixing a set of runtime audio signals based on a set of acoustic paths to determine a reference signal, wherein mixing the set of runtime audio signals comprises applying one of the set of acoustic paths between a first speaker and a first microphone to a second microphone;
receiving at least one composite audio signal that is based on the set of runtime audio signals;
nulling in a direction that is in an acoustic path between a microphone array and at least one speaker based on the at least one composite audio signal; and
reducing echo in the at least one composite audio signal based on the reference signal.

2. The method of claim 1 , further comprising:
outputting a set of output calibration audio signals;
receiving a set of input calibration audio signals based on the set of output calibration audio signals; and
determining the set of acoustic paths based on the set of input calibration audio signals.

3. The method of claim 2 , wherein each of the set of output calibration audio signals is output individually in an output sequence, and wherein each of the set of input calibration audio signals is received individually in an input sequence.

4. The method of claim 1 , wherein the at least one composite audio signal is received by two or more microphones in a wireless communication device, and wherein mixing the set of runtime audio signals and reducing the echo is performed by an audio processing device.

5. The method of claim 1 , further comprising applying a first acoustic path to multiple runtime audio signals.

6. The method of claim 1 , wherein the at least one composite audio signal is received by two or more microphones in a wireless communication device, wherein a mixed-down source per each microphone is communicated, and wherein enhanced speech with echo cancellation/noise suppression is communicated.

7. The method of claim 1 , further comprising determining coefficients for a set of filters that filter speaker audio signals.

8. The method of claim 7 , wherein at least two filters share coefficients.

9. The method of claim 7 , wherein coefficients from a first filter are utilized as coefficients for a second filter.

10. The method of claim 7 , wherein at least one filter is configured to only change an amplitude and delay of an input signal.

11. The method of claim 7 , wherein at least one filter is based on an impulse response.

12. The method of claim 1 , further comprising determining whether to recalibrate based on an adaptive filter.

13. An electronic device for echo reduction, comprising:
mixing circuitry configured to mix a set of runtime audio signals based on a set of acoustic paths to determine a reference signal, wherein the mixing circuitry is configured to apply one of the set of acoustic paths between a first speaker and a first microphone to a second microphone;
two or more microphones configured to receive at least one composite audio signal that is based on the set of runtime audio signals;
beamformer circuitry configured to null in a direction that is in an acoustic path between a microphone array and at least one speaker based on the at least one composite audio signal; and
echo reduction circuitry configured to reduce echo in the at least one composite audio signal based on the reference signal.

14. The electronic device of claim 13 , further comprising:
speakers configured to output a set of output calibration audio signals, wherein the two or more microphones are configured to receive a set of input calibration audio signals based on the set of output calibration audio signals; and
acoustic path determination circuitry configured to determine the set of acoustic paths based on the set of input calibration audio signals.

15. The electronic device of claim 14 , wherein the speakers are configured to output each of the set of output calibration audio signals individually in an output sequence, and wherein the two or more microphones are configured to receive each of the set of input calibration audio signals individually in an input sequence.

16. The electronic device of claim 13 , comprising an audio processing device, wherein the audio processing device is configured to mix the set of runtime audio signals and to reduce the echo.

17. The electronic device of claim 13 , further comprising acoustic path application circuitry configured to apply a first acoustic path to multiple runtime audio signals.

18. The electronic device of claim 13 , wherein the electronic device is configured to communicate a mixed-down source per each microphone and to communicate enhanced speech with echo cancellation/noise suppression.

19. The electronic device of claim 13 , further comprising acoustic path determination circuitry configured to determine coefficients for a set of filters that filter speaker audio signals.

20. The electronic device of claim 19 , wherein at least two filters are configured to share coefficients.

21. The electronic device of claim 19 , wherein a second filter is configured to utilize coefficients from a first filter.

22. The electronic device of claim 19 , wherein at least one filter is configured to only change an amplitude and delay of an input signal.

23. The electronic device of claim 19 , wherein at least one filter is based on an impulse response.

24. The electronic device of claim 13 , further comprising recalibration circuitry configured to determine whether to recalibrate based on an adaptive filter.

25. An apparatus for echo reduction, comprising:
means for mixing a set of runtime audio signals based on a set of acoustic paths to determine a reference signal, wherein the means for mixing the set of runtime audio signals comprises means for applying one of the set of acoustic paths between a first speaker and a first microphone to a second microphone;
means for receiving at least one composite audio signal that is based on the set of runtime audio signals;
means for nulling in a direction that is in an acoustic path between a microphone array and at least one speaker based on the at least one composite audio signal; and
means for reducing echo in the at least one composite audio signal based on the reference signal.

26. The apparatus of claim 25 , further comprising:
means for outputting a set of output calibration audio signals;
means for receiving a set of input calibration audio signals based on the set of output calibration audio signals; and
means for determining the set of acoustic paths based on the set of input calibration audio signals.

27. The apparatus of claim 26 , wherein each of the set of output calibration audio signals is output individually in an output sequence, and wherein each of the set of input calibration audio signals is received individually in an input sequence.

28. The apparatus of claim 25 , wherein the means for mixing the set of runtime audio signals and the means for reducing the echo are included in an audio processing device.

29. The apparatus of claim 25 , further comprising means for applying a first acoustic path to multiple runtime audio signals.

30. The apparatus of claim 25 , wherein a mixed-down source per each microphone is communicated, and wherein enhanced speech with echo cancellation/noise suppression is communicated.

Assignees

• Qualcomm Inc

Inventors

• Mohammad Asif I
• Kim Lae-Hoon
• Visser Erik

Classifications

• H04R3/005 Primary

  for combining the signals of two or more microphones (specially adapted for hearing aids H04R25/407) · CPC title

• H04B3/20

  Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other · CPC title

• H04R2430/23

  Direction finding using a sum-delay beam-former · CPC title

• G10L2021/02082

  the noise being echo, reverberation of the speech · CPC title