Noise cancelling microphone apparatus
First Claim
1. A noise cancelling digital signal processor (DSP), comprising:
- a) a beam-forming module configured to output a main signal and one or more reference signals based on audio signals received from at least two microphones, wherein the beam-forming module includes one or more de-emphasis filters, each of which comprises at least one of a low-pass filter and a frequency response matching filter, each of the one or more de-emphasis filters arranged to filter at least one of the main and reference signals;
b) a voice activity detection module configured to receive the main signal and reference signals and to output a desired voice activity signal, and whereby a first one of the one or more de-emphasis filters is arranged to filter the main signal, and a second one of the one or more de-emphasis filters is arranged to filter the reference signal, prior to reception of the main signal and the reference signal by the voice activity detection module;
c) an adaptive noise cancellation module configured to receive the main signal, reference signals and desired voice activity signal and output an adaptive noise cancelled signal; and
d) a single channel noise reduction module configured to receive the desired voice activity signal and adaptive noise cancellation signal and output a desired speech signal.
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Accused Products
Abstract
Example embodiments include a method of reducing noise include forming a main signal and one or more reference signals at a beam-former based on at least two received audio signals, detecting voice activity at a voice activity detector, where the voice activity detector receives the main and reference signals and outputting a desired voice activity signal, adaptively cancelling noise at an adaptive noise canceller, where the adaptive noise canceller receives the main, reference, and desired voice activity signals and outputs an adaptive noise cancellation signal, and reducing noise at a noise reducer receiving the desired voice activity and adaptive noise cancellation signals and outputting a desired speech signal.
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Citations
8 Claims
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1. A noise cancelling digital signal processor (DSP), comprising:
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a) a beam-forming module configured to output a main signal and one or more reference signals based on audio signals received from at least two microphones, wherein the beam-forming module includes one or more de-emphasis filters, each of which comprises at least one of a low-pass filter and a frequency response matching filter, each of the one or more de-emphasis filters arranged to filter at least one of the main and reference signals; b) a voice activity detection module configured to receive the main signal and reference signals and to output a desired voice activity signal, and whereby a first one of the one or more de-emphasis filters is arranged to filter the main signal, and a second one of the one or more de-emphasis filters is arranged to filter the reference signal, prior to reception of the main signal and the reference signal by the voice activity detection module; c) an adaptive noise cancellation module configured to receive the main signal, reference signals and desired voice activity signal and output an adaptive noise cancelled signal; and d) a single channel noise reduction module configured to receive the desired voice activity signal and adaptive noise cancellation signal and output a desired speech signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification