초록 ▼

An improved noise suppression system (800) is disclosed which performs speech quality enhancement upon the speech-plus-noise signal available at the input (205) to generate a clean speech signal at the output (265) by spectral gain modification. The improvements of the present invention include the

An improved noise suppression system (800) is disclosed which performs speech quality enhancement upon the speech-plus-noise signal available at the input (205) to generate a clean speech signal at the output (265) by spectral gain modification. The improvements of the present invention include the addition of a signal-to-noise ratio (SNR) threshold mechanism (830) to reduce background noise flutter by offsetting the gain rise of the gain tables until a certain SNR threshold is reached, the use of a voice metric calculator (810) to produce more accurate background noise estimates via performing the update decision based on the overall voice-like characteristics in the channels and the time interval since the last update, and the use of a channel SNR modifier (820) to provide immunity to narrowband noise bursts through modification of the SNR estimates based on the voice metric calculation and the channel energies.

대표청구항 ▼

An improved noise suppression system for attenuating the background noise from a noisy input signal to produce a noise-suppressed output signal, said noise suppression system comprising: means for separating the input signal into a plurality of pre-processed signals representative of selected freque

An improved noise suppression system for attenuating the background noise from a noisy input signal to produce a noise-suppressed output signal, said noise suppression system comprising: means for separating the input signal into a plurality of pre-processed signals representative of selected frequency channels; means for generating estimates of the signal-plus-noise energy and the noise energy in each individual channel; means for producing a gain value for each individual channel in response to said channel energy estimates, said gain values having a minimum gain value for each channel, said gain value producing means including threshold means for allowing gain values above said minimum gain value to be prodeced only when said signal-plus-noise energy estimates exceed said noise energy estimates by a predetermined amount; and means for modifying the gain of each of said plurality of pre-processed signals in esponse to said gain values to provide a plurality of post-processed signals.