Conferencing Apparatus that combines a Beamforming Microphone Array with an Acoustic Echo Canceller

• US 20160300584A1
• Filed: 06/23/2016
• Published: 10/13/2016
• Est. Priority Date: 06/11/2011
• Status: Active Grant

• Current Assignee: Clearone Incorporated
• Original Assignee: Clearone Incorporated
• Inventors: Pandey, Ashutosh, Thurston, Darrin T., Lambert, David K., Bathurst, Tracy A.
• Granted Patent: US 9,635,186 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G10L 2021/02082 the noise being echo, reverberation of the speech
• CPC Class Codes: G10L 2021/02166 Microphone arrays; Beamforming
• CPC Class Codes: G10L 21/0208 Noise filtering
• CPC Class Codes: G10L 21/0232 Processing in the frequency domain
• CPC Class Codes: G10L 21/0264 characterised by the type of parameter measurement, e.g. correlation techniques, zero crossing techniques or predictive techniques
• CPC Class Codes: H04M 3/568 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 Class Codes: H04M 9/082 using echo cancellers echo cancellers per se H04B3/23
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 2201/401 2D or 3D arrays of transducers
• CPC Class Codes: H04R 2201/403 Linear arrays of transducers
• CPC Class Codes: H04R 2203/12 Beamforming aspects for stereophonic sound reproduction with loudspeaker arrays
• CPC Class Codes: H04R 2430/20 Processing of the output signals of the acoustic transducers of an array for obtaining a desired directivity characteristic H04R2203/12 takes precedence
• CPC Class Codes: H04R 2430/23 Direction finding using a sum-delay beam-former
• CPC Class Codes: H04R 2499/11 Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's
• CPC Class Codes: H04R 29/007 for public address systems public address systems per se H04R27/00
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

The present disclosure discloses a conferencing apparatus that combines a beamforming microphone array (BMA) with an acoustic echo canceller where the BMA further comprises a plurality of microphones that are oriented to develop a corresponding plurality of microphone signals. The apparatus further includes a processor, memory, and storage where the processor is configured to execute program instructions. The processor performs a beamforming operation to create a plurality of combined signals. In addition, the processor performs an acoustic echo cancellation operation to generate a plurality of combined echo cancelled signals. Further, the processor selects one of the combined echo cancelled signals for transmission to the far end where the signal selection module uses the far end signal as information to inhibit the signal selection module from changing the selection of the combined echo cancelled signals while only the far end signal is active.

Claims

1. A conferencing apparatus that combines a beamforming microphone array with an acoustic echo canceller, comprising:

a beamforming microphone array that further comprises a plurality of microphones wherein each microphone is configured to sense acoustic waves and said plurality of microphones are oriented to develop a corresponding plurality of microphone signals;

a processor, memory, and storage operably coupled to said beamforming microphone array, said processor configured to;

perform a beamforming operation with a beamforming module to combine the plurality of microphone signals from said beamforming microphone array into a plurality of combined signals that is greater in number than one and less in number than the plurality of microphone signals, each of the plurality of combined signals corresponding to a different fixed beam;

perform an acoustic echo cancellation operation with an acoustic echo canceller on the plurality of combined signals to generate a plurality of combined echo cancelled signals; and

select with a signal selection module, one or more of the combined echo cancelled signals for transmission to the far end, wherein said signal selection module uses the far end signal as information to inhibit said signal selection module from changing the selection of the combined echo cancelled signals while only the far end signal is active.

2. The claim of claim 1 wherein said processor is further configured to perform a partial acoustic echo cancellation operation with a partial acoustic echo canceller on a subset of microphone signals which is greater than one and less than the plurality of microphone signals wherein the partial acoustic echo cancellation operation is used to determine that the beamforming microphone array is in a receive only state.

3. The claim of claim 1 wherein said processor is further configured to noise filter the plurality of combined echo cancelled signals.

4. The claim of claim 1 wherein said signal selection module selects the loudest combined echo cancelled signal for transmission to the far end.

5. The claim of claim 1 wherein said processor is further configured to enhance the direction of arrival determination with a voice activity detector.

6. The claim of claim 1 wherein said processor is further configured to perform a direction of arrival determination with a direction of arrival module on the plurality of microphone signals to select one of the plurality of combined echo cancelled signals in response.

7. A method to manufacture a conferencing apparatus that combines a beamforming microphone array with an acoustic echo canceller, comprising:

providing a beamforming microphone array that further comprises a plurality of microphones wherein each microphone is configured to sense acoustic waves and said plurality of microphones are oriented to develop a corresponding plurality of microphone signals;

operably coupling a processor, memory, and storage to said beamforming microphone array, said processor configured to;

perform a beamforming operation with a beamforming module to combine the plurality of microphone signals from said beamforming microphone array into a plurality of combined signals that is greater in number than one and less in number than the plurality of microphone signals, each of the plurality of combined signals corresponding to a different fixed beam;

perform an acoustic echo cancellation operation with an acoustic echo canceller on the plurality of combined signals to generate a plurality of combined echo cancelled signals; and

select with a signal selection module one or more of the combined echo cancelled signals for transmission to the far end, wherein said signal selection module uses the far end signal as information to inhibit said signal selection module from changing the selection of the combined echo cancelled signals while only the far end signal is active.

8. The claim of claim 7 wherein said processor is further configured to perform a partial acoustic echo cancellation operation with a partial acoustic echo canceller on a subset of the microphone signals that is greater than one and less than the plurality of microphone signals wherein the partial acoustic echo cancellation operation is used to determine that the plurality of microphones of said beamforming microphone array are in a receive only state.

9. The claim of claim 7 wherein said processor is further configured to noise filter the plurality of combined echo cancelled signals.

10. The claim of claim 7 wherein said signal selection module selects the loudest combined echo cancelled signal for transmission to the far end.

11. The claim of claim 7 wherein said processor is further configured to enhance the direction of arrival determination with a voice activity detector.

12. The claim of claim 7 wherein said processor is further configured to perform a direction of arrival determination with a direction of arrival module on the plurality of microphone signals to select one of the plurality of combined echo cancelled signals in response.

13. A method to use a conferencing apparatus that combines a beamforming microphone array with an acoustic echo canceller, comprising:

sensing acoustic waves with a beamforming microphone array that further comprises a plurality of microphones wherein said plurality of microphones are oriented to develop a corresponding plurality of microphone signals;

providing a processor, memory, and storage operably coupled to said beamforming microphone array, said processor configured to;

perform a beamforming operation with a beamforming module to combine the plurality of microphone signals from said beamforming microphone array into a plurality of combined signals that is greater in number than one and less in number than the plurality of microphone signals, each of the plurality of combined signals corresponding to a different fixed beam;

perform an acoustic echo cancellation operation with an acoustic echo canceller on the plurality of combined signals to generate a plurality of combined echo cancelled signals; and

select with a signal selection module one or more of the combined echo cancelled signals for transmission to the far end, wherein said signal selection module uses the far end signal as information to inhibit said signal selection module from changing the selection of the combined echo cancelled signals while only the far end signal is active.

14. The claim of claim 13 wherein said processor is further configured to perform a partial acoustic echo cancellation operation with a partial acoustic echo canceller on a subset of the microphone signals that is greater than one and less than the plurality of microphone signals wherein the partial acoustic echo cancellation operation is used to determine that the plurality of microphones of said beamforming microphone array are in a receive only state.

15. The claim of claim 13 wherein said processor is further configured to noise filter the plurality of combined echo cancelled signals.

16. The claim of claim 13 wherein said signal selection module selects the loudest combined echo cancelled signal for transmission to the far end.

17. The claim of claim 13 wherein said processor is further configured to enhance the direction of arrival determination with a voice activity detector.

18. The claim of claim 13 wherein said processor is further configured to perform a direction of arrival determination with a direction of arrival module on the plurality of microphone signals to select one of the plurality of combined echo cancelled signals in response.

19. A non-transitory program storage device readable by a computing device that tangibly embodies a program of instructions executable by the computing device to perform a method to use a conferencing apparatus that combines a beamforming microphone array with an acoustic echo canceller, comprising:

sensing acoustic waves with a beamforming microphone array that further comprises a plurality of microphones wherein said plurality of microphones are oriented to develop a corresponding plurality of microphone signals;

providing a processor, memory, and storage operably coupled to said beamforming microphone array, said processor configured to;

perform a beamforming operation with a beamforming module to combine the plurality of microphone signals from said beamforming microphone array to a plurality of combined signals that is greater in number than one and less in number than the plurality of microphone signals, each of the plurality of combined signals corresponding to a different fixed beam;

perform an acoustic echo cancellation operation with an acoustic echo canceller on the plurality of combined signals to generate a plurality of combined echo cancelled signals; and

select with a signal selection module one of the combined echo cancelled signals for transmission to the far end, wherein said signal selection module uses the far end signal as information to inhibit said signal selection module from changing the selection of the combined echo cancelled signals while only the far end signal is active.

20. The claim of claim 19 wherein said processor is further configured to perform a partial acoustic echo cancellation operation with a partial acoustic echo canceller on a subset of the microphone signals that is greater than one and less than the plurality of microphone signals wherein the partial acoustic echo cancellation operation is used to determine that the plurality of microphones of said beamforming microphone array are in a receive only state.

21. The claim of claim 19 wherein said processor is further configured to noise filter the plurality of combined echo cancelled signals.

22. The claim of claim 19 wherein said multiplexor is selecting the loudest combined echo cancelled signal for transmission to the far end.

23. The claim of claim 19 wherein said processor is further configured to enhance the direction of arrival determination with a voice activity detector.

24. The claim of claim 19 wherein said processor is further configured to perform a direction of arrival determination with a direction of arrival module on the plurality of microphone signals to select one of the plurality of combined echo cancelled signals in response.