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US 7,272,224 B1Granted
Echo cancellation
AssigneeApple Inc.
InventorsJames Oliver Normile, Ryan R. Salsbury
Life of this patent
Estimating the term…
Abstract
A method, apparatus, system, and signal-bearing medium that in an embodiment determine a degree of correlation between a speaker output signal and a microphone input signal and modulate an adaptive gain of an acoustic echo canceller based on the degree of correlation.
Claims36
A method comprising:
- determining a degree of correlation between a speaker output signal and a microphone input signal;
- and
- modulating an adaptive gain of an acoustic echo canceller based on the degree of correlation,
- wherein determining the degree of correlation comprises,
- calculating a power spectrum of the microphone input signal and the speaker output signal,
- calculating ratios of frequency components in the power spectrum
- dividing a number of the ratios that exceed a threshold by a number of discrete frequencies in the power spectrum.
4 more elements
An apparatus comprising:
- means for determining a degree of correlation between a speaker output signal and a microphone input signal;
- and
- means for modulating an adaptive gain of an acoustic echo canceller based on the degree of correlation,
- wherein determining means comprises,
- means for calculating a power spectrum of a microphone input signal and a speaker output signal;
- means for calculating ratios of frequency components in the power spectrum;
- means for dividing a number of the ratios that exceed a threshold by a number of discrete frequencies in the power spectrum.
4 more elements
A signal-bearing medium bearing instructions, wherein the instructions when read and executed perform operations that comprise:
- determining a degree of correlation between a speaker output signal and a microphone input signal;
- and
- modulating an adaptive gain of an acoustic echo canceller based on the degree of correlation,
- wherein the determining comprises,
- calculating a power spectrum of a microphone input signal and a speaker output signal,
- calculating ratios of frequency components in the power spectrum,
- dividing a number of the ratios that exceed a threshold by a number of discrete frequencies in the power spectrum to generate a correlation coefficient.
4 more elements
An electronic device comprising:
- a processor;
- and
- a storage device bearing instructions, which when executed on the processor cause the electronic device to perform operations that comprise:
- determining a degree of correlation between a speaker output signal and a microphone input signal;
- and
- modulating an adaptive gain of an acoustic echo canceller based on the degree of correlation,
- wherein the determining comprises,
- calculating a power spectrum of a microphone input signal and a speaker output signal,
- calculating ratios of frequency components in the power spectrum,
- dividing a number of the ratios that exceed a threshold by a number of discrete frequencies in the power spectrum to generate a correlation coefficient.
7 more elements
Dependencies are inferred from the claim text.