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Voice activity detection driven noise remediator

  • US 5,657,422 A
  • Filed: 01/28/1994
  • Issued: 08/12/1997
  • Est. Priority Date: 01/28/1994
  • Status: Expired due to Term
First Claim
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1. A receiving apparatus for processing a received encoded signal, said received encoded signal comprising a speech component and a noise component, said apparatus comprising:

  • a speech decoder for receiving said encoded signal and generating a decoded signal, said decoded signal comprising a speech component and a noise component;

    an energy estimator connected to said speech decoder for receiving said decoded signal and for generating an estimated energy signal representing the acoustic energy of said decoded signal;

    a noise estimator connected to said energy estimator for receiving said estimated energy signal and for generating an estimated noise signal representing the average background noise level in said decoded signal;

    a high pass filter driver connected to said noise estimator and said speech decoder for receiving said estimated noise signal and said decoded signal, and for high pass filtering said decoded signal based upon said estimated noise signal, and for generating a high pass filtered output signal;

    a voice activity detector connected to said energy estimator and said noise estimator for receiving said estimated energy signal and said estimated noise signal and for generating a voice detection signal representing whether said decoded signal contains a speech component;

    an attenuator calculator connected to said voice activity detector for receiving said voice detection signal and for generating an attenuation signal representing the attenuation to be applied to said high pass filtered signal;

    a noise generator connected to said noise estimator for receiving said estimated noise signal and for generating a comfort noise signal; and

    a speech attenuator/comfort noise inserter connected to said high pass filter driver, said shaped noise generator, and said attenuator calculator, for receiving said high pass filtered output signal, said comfort noise signal, and said attenuation signal, and for attenuating said high pass filtered output signal and inserting said comfort noise signal into said high pass filtered output signal based upon said attenuation signal, and for generating a processed high pass filtered signal wherein said speech decoder, noise estimator and said voice activity detector are in said receiving apparatus.

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