The Improvement and Implementation of Speech Enhancement Based on Mel frequency Wiener Filtering

The main purpose of speech enhancement is to eliminate the noise in noisy speech signal and extract pure speech signal, which has important significance to improve the performance of digital hearing aid. This paper mainly studies the speech enhancement technology in digital hearing aids. Using the improved second order Mel twisted Wiener filtering algorithm, introduced short-time amplitude spectrum of dynamic decision voice activity detection (VAD) algorithm, which solves the part deviation of estimation stationary noise. At the same time, add a priori SNR gain factor based on decomposition of pure noise frame to increase the degree of inhibition, and contain the speech frame is reduced the extent of the suppression. Update the SNR prediction and low SNR ratio and Wiener filtering gain coefficient, automatic gain control (AGC) effect is obvious. The experimental results show that the output SNR of the processed signal is obviously improved, and the speech intelligibility is good and the quality is high. Significantly improve the recognition ability of weak signal.