Noise reduction and comfort noise gain control using bark band weiner filter and linear attenuation
AssigneeAcoustic Technologies, Inc.
InventorSamuel Ponvarma Ebenezer
Life of this patent
Estimating the term…
Abstract
A combination of noise suppression using a Bark band modified Weiner filter and linear noise reduction improves elimination of noise in a telephone. A detector for detecting long, non-speech intervals is coupled to the output of the noise suppresser and controls selection of noise suppression or noise reduction. A gain smoothing filter has a long time constant when noise reduction is used and provides a gradual transition from one level of gain to another. Comfort noise is smoothly inserted by updating the data for generating comfort noise only during detected long, non-speech intervals.
Claims8
In a telephone having an audio processing circuit including an analysis circuit for dividing a audio signal into a plurality of frames, each frame containing a plurality of samples, a noise suppression circuit, and a noise reduction circuit, the improvement comprising:
- means for detecting long non-speech intervals;
- and
- means for switching to noise reduction from noise suppression when a long, non-speech interval is detected.
In a telephone including a noise suppression circuit having a circuit for estimating background noise and having a comfort noise generator coupled to said noise suppression circuit for generating comfort noise based on data from said circuit for estimating background noise, the improvement comprising:
- means for detecting long non-speech intervals;
- and
- means coupled to said circuit for postponing an estimate when said means for detecting long non-speech intervals detects a long non-speech interval.
Dependencies are inferred from the claim text.