Post-Processing Noise Suppressor with Adaptive Gain-Flooring for Cell-Phone Handsets and IC Recorders

This paper proposes a post-processing noise suppressor with adaptive gain-flooring. By controlling gain-flooring based on voice activity and an output-SNR, distortion of the enhanced speech is reduced with natural transition between a speech and a non-speech section. Subjective evaluation results, with a preprocessing noise suppressor, a codec and a post-processing noise suppressor connected in tandem, show that the post-processing noise suppressor improves the five-grade mean opinion score by as much as 0.5 when suppression by the preprocessing noise suppressor is insufficient. The proposed post-processing noise suppressor is promising for the receiver in cell-phone handsets and IC recorders.