System and method for reducing noise
OwnerThomas W. Holdeninventor
Life of this patent
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Abstract
A noise reduction system for removing unwanted audio noise during a pause. The system receives an intelligence plus noise signal that is split and fed to a first rectifier having a first polarity, and through a filter to a second rectifier having a polarity opposite to the first rectifier. The filter removes components below a frequency where most energy-frequency is distributed in human speech. The output of the rectifiers is summed to produce an output signal when most audio noise between pauses in voice is reduced.
Claims15
A method for reducing noise between pauses in audio communication having an energy distribution, the method comprising the steps of:
- providing an audio signal having an intelligence plus noise component and a noise only component;
- determining a frequency value below which most of the energy distribution in the audio communication occurs;
- filtering and increasing the amplitude of a portion of the audio signal having a frequency less than the frequency value determined;
- rectifying the filtered audio signal;
- rectifying the audio signal with a polarity opposite to the polarity of the rectified filtered audio signal and combining the rectified filtered audio signal with the rectified audio signal to produce an intelligence syllable signal;
- and
- passing the intelligence component plus noise of the audio signal in response to the intelligence syllable signal.
A system for reducing noise in an audio signal during pauses between the audio signals, syllables, the system comprising:
- means for rectifying the audio signal to provide a negative rectified signal;
- means for filtering the audio signal to remove frequency components in said audio signal below a predetermined threshold to provide a filtered audio signal;
- means for rectifying the filtered audio signal to provide a positive rectified signal with frequency components above the predetermined threshold;
- means for combining the negative rectified signal with the positive rectified signal to provide a combined signal, and for filtering frequency components of the signal greater than a second predetermined frequency to provide a plurality of output pulses which each pulse having a duration corresponding to the duration of audio signal syllables;
- and
- means for passing the audio signal in response to said pulse output, and for preventing the passage of the audio signal between output pulses.
A system for reducing noise in audio signals during pauses between intelligent signal syllables, the system comprising:
- means responsive to the audio signals for providing a pulse having a duration corresponding to the duration of an audio signal syllable, the pulse providing means including means for filtering frequency components above a frequency corresponding to audio frequencies where most of the energy is distributed in human voice to provide a SUM signal, the pulse providing means further including a filter means for amplifying signals having a frequency less than a predetermined value, a rectifier means for rectifying the amplified signal and for rectifying the audio signals, and means for summing the rectified signals to provide the pulse;
- and
- means responsive to the pulse for passing audio signals for the duration of the syllable and for preventing the passage of noise between audio signal syllables.
A system for reducing noise between voice syllables in audio communications comprising:
- a signal input for receiving an intelligence plus noise signal or a noise only signal;
- filter means connected to said signal input for reducing the amplitude of intelligent plus noise signals and noise only signals that have a frequency less than a predetermined value;
- first rectifier means connected to said signal input and having an output for rectifying in a first polarity the intelligence signal plus noise and the noise only signal;
- second rectifier means connected to said filter and having an output for rectifying the amplitude reduced intelligence signal plus noise and amplitude reduced noise only signal with a polarity opposite the first polarity;
- means for summing said first rectifier means output with said second rectifier means output to produce a pulse output signal;
- and
- means connected to said signal input and responsive to said pulse output signal for preventing passage of said noise only signal while passing the intelligent signal plus noise.
A method for reducing noise between pauses in audio communication, the method comprising the steps of:
- providing an audio signal having an intelligence plus noise component and a noise only component;
- filtering the amplitude of a portion of the audio signal having a frequency less than a predetermined value;
- rectifying the filtered audio signal;
- rectifying the audio signal with a polarity opposite to the polarity of the filtered audio signal combining the rectified filtered audio signal with the rectified audio signal to produce an intelligence syllable signal;
- and
- passing the intelligence component plus noise of the audio signal in response to the intelligence syllable signal.
Dependencies are inferred from the claim text.