Cross-domain processing for noise and echo suppression
First Claim
Patent Images
1. A computing device, comprising:
- a processor;
a microphone;
a speaker configured to render audio based at least in part on an output audio signal; and
memory, accessible by the processor and storing instructions that are executable by the processor to perform acts comprising;
receiving an input audio signal from the microphone, wherein the input audio signal includes an echo component resulting from the rendered audio;
estimating an echo signal corresponding to the echo component of the input audio signal based at least in part on the output audio signal;
subtracting the estimated echo signal from the input audio signal to produce an echo-suppressed audio signal;
calculating a frequency-domain representation of the echo-suppressed audio signal;
calculating a frequency-domain representation of the estimated echo signal;
estimating noise values corresponding to different frequencies of the echo-suppressed audio signal based at least in part on the calculated frequency-domain representation of the echo-suppressed audio signal;
calculating gain values corresponding respectively to the different frequencies based at least in part on (a) the estimated noise values of the echo-suppressed audio signal and (b) the calculated frequency-domain representation of the estimated echo signal;
adjusting the frequency-domain representation of the echo-suppressed audio signal at the different frequencies in accordance with the calculated gain values corresponding to the different frequencies to produce an adjusted frequency-domain representation of the echo-suppressed audio signal; and
producing a processed audio signal based at least in part on the adjusted frequency-domain representation of the echo-suppressed audio signal.
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Abstract
An audio-based system may perform noise and echo suppression by initially processing an audio signal that is subject to acoustic echo or echo resulting from other system characteristics. The audio signal is processed in the time domain using an adaptive echo-cancellation filter. The audio is then further processed in the frequency domain to simultaneously reduce background noise and residual echo.
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Citations
19 Claims
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1. A computing device, comprising:
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a processor; a microphone; a speaker configured to render audio based at least in part on an output audio signal; and memory, accessible by the processor and storing instructions that are executable by the processor to perform acts comprising; receiving an input audio signal from the microphone, wherein the input audio signal includes an echo component resulting from the rendered audio; estimating an echo signal corresponding to the echo component of the input audio signal based at least in part on the output audio signal; subtracting the estimated echo signal from the input audio signal to produce an echo-suppressed audio signal; calculating a frequency-domain representation of the echo-suppressed audio signal; calculating a frequency-domain representation of the estimated echo signal; estimating noise values corresponding to different frequencies of the echo-suppressed audio signal based at least in part on the calculated frequency-domain representation of the echo-suppressed audio signal; calculating gain values corresponding respectively to the different frequencies based at least in part on (a) the estimated noise values of the echo-suppressed audio signal and (b) the calculated frequency-domain representation of the estimated echo signal; adjusting the frequency-domain representation of the echo-suppressed audio signal at the different frequencies in accordance with the calculated gain values corresponding to the different frequencies to produce an adjusted frequency-domain representation of the echo-suppressed audio signal; and producing a processed audio signal based at least in part on the adjusted frequency-domain representation of the echo-suppressed audio signal. - View Dependent Claims (2, 3, 4, 5)
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6. A method, comprising:
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estimating an echo signal corresponding to an echo component of an input audio signal; subtracting the estimated echo signal from the input audio signal to produce an echo-suppressed audio signal; calculating a frequency-domain representation of the echo-suppressed audio signal; calculating a frequency-domain representation of the estimated echo signal; estimating noise values corresponding to different frequencies of the echo-suppressed audio signal based at least in part on the calculated frequency-domain representation of the echo-suppressed audio signal; calculating gain values corresponding respectively to the different frequencies based at least in part on (a) the estimated noise values of the echo-suppressed audio signal and (b) the calculated frequency-domain representation of the estimated echo; processing the frequency-domain representation of the echo-suppressed audio signal at the different frequencies in accordance with the calculated gain values to reduce noise and residual echo components of the echo-suppressed audio signal; and producing a transmit audio signal based at least in part on the processed frequency-domain representation of the echo-suppressed audio signal. - View Dependent Claims (7, 8, 9, 10, 11, 12)
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13. One or more non-transitory computer-readable media storing computer-executable instructions that, when executed by one or more processors, cause the one or more processors to perform acts comprising:
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processing an audio signal by linear adaptive filtering to reduce an echo component of the audio signal; and processing the audio signal in a frequency domain by applying gain values to a frequency-domain representation of the audio signal, wherein the gain values are based at least in part noise components of the audio signal over a spectrum of frequencies and estimated echo values of the audio signal over the spectrum of frequencies, the processing the audio signals in the frequency domain to (a) reduce noise in the audio signal and (b) further reduce the echo component in the audio signal. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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Specification