Noise suppression system

Details Noise suppression system Noise suppression system

1987-10-01

1989-03-07

Ng, Jin F.

Electrical audio signal processing systems and devices

Noise or distortion suppression

Interpolation

381 47, 381 71, 455305, 455306, 328167, H04B 1500

Patent

active

048114049

ABSTRACT:
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.

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