Reducing noise in audio systems
AssigneeMH Acoustics, LLC, a Delaware corporation
InventorGary W. Elko
Life of this patent
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Abstract
Two or more microphones receive acoustic signals and generate audio signals that are processed to determine what portion of the audio signals result from (i) incoherence between the audio signals and/or (ii) audio-signal sources having propagation speeds different from the acoustic signals. The audio signals are filtered to reduce that portion of one or more of the audio signals. The present invention can be used to reduce turbulent wind-noise resulting from wind or other airjets blowing across the microphones. Time-dependent phase and amplitude differences between the microphones can be compensated for based on measurements made in parallel with routine audio system processing.
Claims45
A method for processing audio signals generated by two or more microphones receiving acoustic signals, comprising the steps of:
- (a) determining a portion of the audio signals resulting from one or more of (i) incoherence between the audio signals and (ii) one or more audio-signal sources having propagation speeds different from the acoustic signals;
- and
- (b) filtering at least one of the audio signals to reduce the determined portion.
An audio system for processing audio signals generated by two or more microphones receiving acoustic signals, the audio system comprising:
- (a) a signal processor configured to determine a portion of the audio signals resulting from one or more of (i) incoherence between the audio signals and (ii) one or more audio-signal sources having propagation speeds different from the acoustic signals;
- and
- (b) a filter configured to filter at least one of the audio signals to reduce the determined portion.
A consumer device comprising:
- (a) two or more microphones configured to receive acoustic signals and to generate audio signals;
- (b) a signal processor configured to determine a portion of the audio signals resulting from one or more of (i) incoherence between the audio signals and (ii) one or more audio-signal sources having propagation speeds different from the acoustic signals;
- and
- (c) a filter configured to filter at least one of the audio signals to reduce the determined portion.
A method for processing audio signals generated in response to a sound field by at least two microphones of an audio system, comprising the steps of:
- (a) filtering the audio signals to compensate for a phase difference between the at least two microphones;
- (b) generating a revised phase difference between the at least two microphones based on the audio signals;
- and
- (c) updating, based on the revised phase difference, at least one calibration parameter used during the filtering of step (a).
An audio system comprising:
- (a) a filter configured to filter audio signals generated in response to a sound field by at least two microphones to compensate for a phase difference between the at least two microphones;
- and
- (b) a signal processor configured to:
- (1) generate a revised phase difference between the at least two microphones based on the audio signals;
- and
- (2) update, based on the revised phase difference, at least one calibration parameter used by the filter.
A consumer device comprising:
- (a) at least two microphones;
- (b) a filter configured to filter audio signals generated in response to a sound field by the at least two microphones to compensate for a phase difference between the at least two microphones;
- and
- (c) a signal processor configured to:
- (1) generate a revised phase difference between the at least two microphones based on the audio signals;
- and
- (2) update, based on the revised phase difference, at least one calibration parameter used by the filter.
Dependencies are inferred from the claim text.