Multi-channel acoustic echo cancellation

A method of operating a playback device having a first speaker driver and at least a second speaker driver, the method comprising:

• receiving, via a network interface of the playback device, a source stream of audio comprising source audio content to be played back by the playback device, wherein the source audio content comprises a first channel stream of audio and a second channel stream of audio;
• producing a first channel audio output by playing back, via the first speaker driver, the first channel stream of audio;
• producing a second channel audio output by playing back, via the second speaker driver, the second channel stream of audio;
• receiving, via one or more microphones, a captured stream of audio comprising (i) a first portion corresponding to the first channel audio output and (ii) a second portion corresponding to the second channel audio output, wherein the captured stream of audio has a first signal-to-noise ratio;
• determining a set of signal components from at least one of the first channel stream of audio or the second channel stream of audio;
• selecting a subset of the set of signal components;
• performing acoustic echo cancellation on the subset of the set of signal components and thereby producing an acoustic echo cancellation output;
• and
• applying the acoustic echo cancellation output to the captured stream of audio and thereby increasing the signal-to noise ratio of the captured stream of audio from the first signal-to-noise ratio to a second signal-to-noise ratio that is greater than the first signal-to-noise ratio.

A non-transitory computer-readable medium, wherein the non-transitory computer-readable medium is provisioned with program instructions that, when executed by at least one processor, cause a playback device to:

• receive, via a network interface of the playback device, a source stream of audio comprising source audio content to be played back by the playback device, wherein the source audio content comprises a first channel stream of audio and a second channel stream of audio;
• produce a first channel audio output by playing back, via a first speaker driver of the playback device, the first channel stream of audio;
• produce a second channel audio output by playing back, via a second speaker driver of the playback device, the second channel stream of audio;
• receive, via one or more microphones, a captured stream of audio comprising (i) a first portion corresponding to the first channel audio output and (ii) a second portion corresponding to the second channel audio output, wherein the captured stream of audio has a first signal-to-noise ratio;
• determine a set of signal components from at least one of the first channel stream of audio or the second channel stream of audio;
• select a subset of the set of signal components;
• perform acoustic echo cancellation on the subset of the set of signal components and thereby produce an acoustic echo cancellation output;
• and
• apply the acoustic echo cancellation output to the captured stream of audio and thereby increase the signal-to noise ratio of the captured stream of audio from the first signal-to-noise ratio to a second signal-to-noise ratio that is greater than the first signal-to-noise ratio.