Method and apparatus for robust acoustic feedback cancellation
AssigneeStarkey Laboratories, Inc.
InventorsCarlos Renato Calcada Nakagawa, Karim Helwani, Ivo Merks
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Abstract
The present subject matter can improve robustness of performance of acoustic feedback cancellation in the presence of strong acoustic disturbances. In various embodiments, an optimization criterion determined to enhance robustness of an adaptive feedback canceller in an audio device against disturbances in an incoming audio signal can be applied such that the adaptive feedback canceller remains in a converged state in response to presence of the disturbances.
Claims20
A method for adaptive acoustic feedback cancellation in an audio device, comprising:
- applying an optimization criterion determined to enhance robustness of an adaptive feedback canceller of the audio device by keeping disturbances in an incoming audio signal of the audio device from resulting in divergence of the adaptive feedback canceller, the adaptive feedback canceller configured to produce an estimate of a feedback signal, the disturbances including onsets of the incoming audio signal of the audio device, the application of the optimization criterion maintaining the adaptive feedback canceller in a converged state in presence of the disturbances, including detecting the onsets of the incoming audio signal using a threshold and adjusting the adaptive feedback canceller using an error signal resulting from subtracting the estimate of the feedback signal from the incoming audio signal in response to each detection of the onsets of the incoming audio signal,
- wherein adjusting the adaptive feedback canceller using the error signal includes constraining the error signal and updating the adaptive feedback canceller using the constrained error signal.
A method for operating a processor of an audio device for adaptive acoustic feedback cancellation, comprising:
- operating an adaptive feedback canceller of the processor in a converged state, including producing an estimate of a feedback signal;
- producing an error signal by subtracting h estimate of the feedback signal ro an incoming audio signal;
- detecting onsets of the incoming audio signal received by the audio device using a threshold;
- and
- adjusting the adaptive feedback canceller using the error signal to maintain the adaptive feedback canceller in the converged state in response to a detection of each of the onsets of the incoming audio signal by keeping the detected onset of the incoming audio signal from resulting in divergence of the adaptive feedback canceller,
- wherein adjusting the adaptive feedback canceller using the error signal includes constraining the error signal and updating the adaptive feedback canceller using the constrained error signal.
An audio device, comprising:
- a microphone configured to receive an input sound and to produce a microphone signal representative of the received sound;
- an audio processing circuit configured to process the microphone sound to produce a loudspeaker signal, the audio processing circuit including an adaptive feedback canceller configured to cancel acoustic feedback in the microphone signal and configured to produce a feedback estimate being an estimate of the acoustic feedback in the microphone signal, to constrain an error signal being a difference between the microphone signal and the feedback estimate, and to be updated using the constrained error signal by applying an optimization criterion determined to enhance robustness by keeping disturbances in the microphone signal from resulting in divergence of the adaptive feedback canceller, the disturbances including onsets of the microphone signal, such that the adaptive feedback canceller remains convergent in the presence of the disturbances, the audio processing circuit configured to detect the onsets of the microphone signal using a threshold and to adjust the adaptive feedback canceller in response to each detection of the onsets of the microphone signal;
- and
- a loudspeaker configured to produce an output sound using the loudspeaker signal.
Dependencies are inferred from the claim text.