Spatial quiescence protection for multi-channel acoustic echo cancellation
First Claim
Patent Images
1. A system comprising:
- multiple receive out channels;
a microphone input channel; and
decision circuitry configured to;
determine a nominal level of echo suppression for the microphone input channel responsive to an estimated receive out signal level and an echo cancellation estimate;
detect a transition from spatial quiescence to spatial richness in the multiple receive out channels; and
in response to the transition, trigger a change comprising additional echo suppression on the microphone input channel over the nominal amount.
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Abstract
A system performs residual echo suppression on a microphone signal that receives, e.g., voice commands, and that is exposed to echo from multiple speakers. An example is a smartphone that receives voice commands while the smartphone is playing music through stereo speakers. The system estimates residual echo level in different ways, and determines which estimate to use. The technique responds well to the difficult to handle scenario of a spatially quiescent image suddenly transitioning to a spatially rich image. Even in the face of such difficult scenarios, the system detects and removes residual echo from the microphone signal, instead of allowing the undesired residual echo to pass through.
36 Citations
20 Claims
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1. A system comprising:
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multiple receive out channels; a microphone input channel; and decision circuitry configured to; determine a nominal level of echo suppression for the microphone input channel responsive to an estimated receive out signal level and an echo cancellation estimate; detect a transition from spatial quiescence to spatial richness in the multiple receive out channels; and in response to the transition, trigger a change comprising additional echo suppression on the microphone input channel over the nominal amount. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A system comprising:
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a microphone input; a first audio output; a second audio output; circuitry in communication with the microphone input, first audio output, and the second audio output, the circuitry configured to; determine a first residual echo level estimate for the microphone input according to an estimated audio out signal level and an echo cancellation estimate; determine a second residual echo level estimate for the microphone input, the circuitry configured to adjust the second residual echo level estimate responsive to a correlation between the first audio output and the second audio output; responsive to the correlation, detect a transition between spatial quiescence to spatial richness; and responsive to the transition, provide the second residual echo level estimate to residual echo suppression circuitry for the microphone input to trigger a change comprising additional echo suppression over a nominal amount that would be applied when the first residual echo level estimate is provided. - View Dependent Claims (14, 15, 16)
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17. A method comprising:
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detecting a transition from spatial quiescence to spatial richness among multiple receive out channels; and in response to the transition, triggering a change comprising additional echo suppression on a microphone input channel over a nominal amount that would be applied when a first residual echo level estimate for the microphone input channel is determined according to an estimated receive out signal level and an echo cancellation estimate. - View Dependent Claims (18, 19, 20)
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Specification