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Integrated frequency-domain voice coding using an adaptive spectral enhancement filter

  • US 6,070,137 A
  • Filed: 01/07/1998
  • Issued: 05/30/2000
  • Est. Priority Date: 01/07/1998
  • Status: Expired due to Term
First Claim
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1. A system for encoding voice with integrated noise suppression, comprising:

  • a sampler which converts an analog audio signal into frames of time-domain audio samples;

    a voice activity detector operatively coupled to the sampler for determining presence or absence of speech in a current frame;

    a transformer operatively coupled to the sampler for transforming the frame of time-domain audio samples to a frequency-domain representation;

    a noise model adapter operatively associated with the voice activity detector and the transformer for updating a noise model using a current frame if the voice activity detector determines there is an absence of speech;

    a transformer and filter creator operatively coupled to the transformer and the noise model adaptor to create a noise suppression filter; and

    a spectral estimator operatively coupled to the transformer and the transformer and filter creator to remove noise characteristics from the frequency-domain representation of the current frame using the noise suppression filter and to develop a set of spectral magnitudes.

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