Multi-aural MMSE analysis techniques for clarifying audio signals
First Claim
1. A method for clarifying an audio signal comprising:
- receiving a primary audio signal and a reference audio signal, each audio signal including a plurality of frequency bands, an unknown target component, and an unknown noise component;
determining a noise estimate of the unknown noise component from the reference audio signal;
incorporating the noise estimate into a minimum mean squared error analysis;
subjecting each frequency band of the plurality of frequency bands of the primary audio signal to the minimum mean squared error analysis;
assigning a confidence interval as a measure of statistical likelihood of dominance of the unknown target component in each frequency band of the plurality of frequency bands based on a result of the minimum mean squared analysis;
modifying an audio output level of each frequency band of the primary audio signal based on the confidence interval of that frequency band to provide a modified output frequency band; and
combining the modified output frequency bands for each frequency band of the plurality of frequency bands of the primary audio signal to provide a clarified output audio signal substantially reduced in the unknown noise component.
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Accused Products
Abstract
Techniques for processing audio signals include removing noise from the audio signals or otherwise clarifying the audio signals prior to outputting the audio signals. The disclosed techniques may employ minimum mean squared error (MMSE) analyses on audio signals received from a primary microphone and at least one reference microphone, and to techniques in which the MMSE analyses are used to reduce or eliminate noise from audio signals received by the primary microphone. Optionally, confidence intervals may be assigned to different frequency bands of an audio signal, with each confidence interval corresponding to a likelihood that its respective frequency band includes targeted audio, and each confidence interval representing a contribution of its respective frequency band in a reconstructed audio signal from which noise has been removed.
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Citations
24 Claims
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1. A method for clarifying an audio signal comprising:
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receiving a primary audio signal and a reference audio signal, each audio signal including a plurality of frequency bands, an unknown target component, and an unknown noise component; determining a noise estimate of the unknown noise component from the reference audio signal; incorporating the noise estimate into a minimum mean squared error analysis; subjecting each frequency band of the plurality of frequency bands of the primary audio signal to the minimum mean squared error analysis; assigning a confidence interval as a measure of statistical likelihood of dominance of the unknown target component in each frequency band of the plurality of frequency bands based on a result of the minimum mean squared analysis; modifying an audio output level of each frequency band of the primary audio signal based on the confidence interval of that frequency band to provide a modified output frequency band; and combining the modified output frequency bands for each frequency band of the plurality of frequency bands of the primary audio signal to provide a clarified output audio signal substantially reduced in the unknown noise component. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for clarifying an audio signal comprising:
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receiving a primary audio signal and a reference audio signal, each audio signal including a plurality of frequency bands, an unknown target component, and an unknown noise component; subjecting the primary audio signal to an adaptive time domain filter to provide a filtered audio signal; determining a noise estimate of the unknown noise component using the reference audio signal; tailoring a minimum mean squared error analysis based on the noise estimate; and subjecting each frequency band of the plurality of frequency bands of the filtered audio signal to the minimum mean squared error analysis; assigning a confidence interval as a measure of statistical likelihood of dominance of the unknown target component in to each frequency band of the plurality of frequency bands of the filtered audio signal based on a result of the minimum mean squared analyses; modifying an audio output level of each frequency band of the filtered audio signal based on the confidence interval of that frequency band to provide a modified output frequency band; and combining the modified output frequency bands for each frequency band of the plurality of frequency bands of the filtered audio signal to provide a clarified output audio signal substantially reduced in the unknown noise component.
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16. An electronic device configured to receive audio signals, comprising:
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a primary audio channel for receiving a primary audio signal; a reference audio channel for receiving a reference audio signal; a processor programmed to; receive the primary audio signal from the primary audio channel and the reference audio signal from the reference audio channel; process the reference audio signal to provide a noise estimate of an unknown noise component; generate a minimum mean squared error analysis that accounts for the noise estimate of the unknown noise component; subject a plurality of frequency bands of the primary audio signal to the minimum mean squared error analysis; compare a result of the minimum mean squared analysis of each frequency band of the plurality of frequency bands of the primary audio signal to a result of the minimum mean squared analysis of a corresponding frequency band of the plurality of frequency bands of the reference audio signal to provide a frequency band comparison; assign a confidence interval as a measure of statistical likelihood of dominance of an unknown target component relative to the unknown noise component for each frequency band of the plurality of frequency bands of the primary audio signal based on the frequency band comparison that corresponds to that frequency band; adjust an output power of the frequency band based on the confidence interval to provide a modified output frequency band; and combine the modified output frequency bands for each frequency band of the plurality of frequency bands of the primary audio signal to provide a clarified output audio signal substantially reduced in the unknown noise component; and cause an output element to output the clarified output audio signal; and wherein the output element is in communication with the processor. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24)
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Specification