Partially adaptive audio beamforming systems and methods

1 . An audio device configured to receive a reference signal, comprising:

a plurality of microphones configured to generate a plurality of audio signals;

a loudspeaker configured to play back the reference signal; and

a first beamformer configured to generate a first beamformed signal based on the plurality of audio signals and a set of beamformer coefficients associated with a steering vector, wherein the first beamformer is configured to process the plurality of audio signals using a frequency domain beamforming technique with a stored beamforming parameter associated with the loudspeaker, wherein the stored beamforming parameter is based on echo from sound played on the loudspeaker.

2 . The audio device of claim 1 , further comprising a downstream processing module in communication with the first beamformer and the reference signal, the downstream processing module configured to perform acoustic echo cancellation of the reference signal on the first beamformed signal to generate a processed beamformed signal.

3 . The audio device of claim 1 , further comprising:

a second beamformer configured to generate a second beamformed signal based on the plurality of audio signals and the steering vector, wherein the steering vector is associated with a desired sound source location and the first beamformed signal is associated with a lobe steered towards the desired sound source location;

a voice activity detector configured to determine when voice activity is detected in the reference signal; and

a switch in communication with the first beamformer, the second beamformer, the voice activity detector, and a downstream processing module, the switch configured to:

based on the voice activity being detected in the reference signal, select the first beamformed signal for transmission to the downstream processing module; and

based on the voice activity not being detected in the reference signal, select the second beamformed signal for transmission to the downstream processing module.

4 . The audio device of claim 3 , further comprising the downstream processing module in communication with the first beamformer, the second beamformer and the reference signal, the downstream processing module configured to:

based on the voice activity being detected in the reference signal, perform acoustic echo cancellation of the reference signal on the first beamformed signal to generate a processed beamformed signal; and

based on the voice activity not being detected in the reference signal, process the second beamformed signal to generate the processed beamformed signal.

5 . The audio device of claim 1 , wherein the frequency domain beamforming technique comprises a minimum variance distortionless response (MVDR) beamforming technique performed in a frequency domain.

6 . The audio device of claim 1 , wherein the steering vector is associated with a desired sound source location and the first beamformed signal is associated with a lobe steered towards the desired sound source location.

7 . The audio device of claim 1 , wherein the plurality of microphones and the loudspeaker are disposed in a same housing.

8 . The audio device of claim 1 , further comprising:

a second beamformer configured to generate a second beamformed signal based on the plurality of audio signals and the steering vector, wherein the steering vector is associated with a desired sound source location and the first beamformed signal is associated with a lobe steered towards the desired sound source location.

9 . The audio device of claim 8 , further comprising:

a first voice activity detector configured to determine when voice activity is detected in the reference signal; and

a second voice activity detector configured to determine when voice activity is detected in at least one of the plurality of audio signals, wherein:

based on (1) the voice activity not being detected in the reference signal by the first voice activity detector and (2) the voice activity being detected in at least one of the plurality of audio signals by the second voice activity detector, the audio device is configured to:

update the steering vector towards a desired sound source; and

update the set of beamformer coefficients for the first beamformer, based on the updated steering vector and the stored beamforming parameter; and

based on (1) the voice activity not being detected in the reference signal by the first voice activity detector and (2) the voice activity not being detected in at least one of the plurality of audio signals by the second voice activity detector, the audio device is configured to:

update the steering vector towards the desired sound source.

10 . The audio device of claim 1 ,

wherein the stored beamforming parameter comprises a stored inverse covariance matrix; and

wherein the first beamformer is further configured to update the stored inverse covariance matrix based on calibration audio played on the loudspeaker.

11 . The audio device of claim 1 , wherein the first beamformer is further configured to regenerate the stored beamforming parameter, based on monitoring a performance of an acoustic echo canceller of a downstream processing module of the audio device.

12 . A method, comprising:

receiving a plurality of audio signals from a plurality of microphones;

receiving a reference signal for playback on a loudspeaker; and

generating a first beamformed signal, using a first beamformer, based on the plurality of audio signals and a set of beamformer coefficients associated with a steering vector, wherein generating the first beamformed signal comprises processing the plurality of audio signals using a frequency domain beamforming technique with a stored beamforming parameter associated with the loudspeaker, wherein the stored beamforming parameter is based on echo from sound played on the loudspeaker.

13 . The method of claim 12 , further comprising performing acoustic echo cancellation of the reference signal on the first beamformed signal to generate a processed beamformed signal.

14 . The method of claim 12 , further comprising:

generating a second beamformed signal, using a second beamformer, based on the plurality of audio signals and the steering vector;

determining when voice activity is detected in the reference signal;

based on the voice activity being detected in the reference signal, selecting the first beamformed signal for transmission to a downstream processing module; and

based on the voice activity not being detected in the reference signal, selecting the second beamformed signal for transmission to the downstream processing module.

15 . The method of claim 14 , further comprising:

based on the voice activity being detected in the reference signal, performing acoustic echo cancellation of the reference signal on the first beamformed signal to generate a processed beamformed signal, using the downstream processing module; and

based on the voice activity not being detected in the reference signal, processing the second beamformed signal to generate the processed beamformed signal, using the downstream processing module.

16 . The method of claim 12 , wherein the frequency domain beamforming technique comprises a minimum variance distortionless response (MVDR) beamforming technique performed in a frequency domain.

17 . The method of claim 12 , wherein the steering vector is associated with a desired sound source location and the first beamformed signal is associated with a lobe steered towards the desired sound source location.

18 . The method of claim 12 , wherein the plurality of microphones and the loudspeaker are disposed in a same housing.

19 . The method of claim 12 , further comprising:

generating a second beamformed signal based on the plurality of audio signals and the steering vector, wherein the steering vector is associated with a desired sound source location and the first beamformed signal is associated with a lobe steered towards the desired sound source location.

20 . The method of claim 19 , further comprising:

determining, by a first voice activity detector, when voice activity is detected in the reference signal;

determining, by a second voice activity detector, when voice activity is detected in at least one of the plurality of audio signals;

based on (1) the voice activity not being detected in the reference signal by the first voice activity detector and (2) the voice activity being detected in at least one of the plurality of audio signals by the second voice activity detector:

updating the steering vector towards a desired sound source; and

updating the set of beamformer coefficients based on the updated steering vector and the stored beamforming parameter; and

based on (1) the voice activity not being detected in the reference signal by the first voice activity detector and (2) the voice activity not being detected in at least one of the plurality of audio signals by the second voice activity detector:

updating the steering vector towards the desired sound source.

21 . The method of claim 12 ,

wherein the stored beamforming parameter comprises a stored inverse covariance matrix;

the method further comprising updating the stored inverse covariance matrix based on calibration audio played on the loudspeaker.

22 . The method of claim 12 , further comprising regenerating the stored beamforming parameter, based on monitoring a performance of an acoustic echo canceller of a downstream processing module.