Enhancement of noisy speech signal based on variance and modified gain function with PDE preprocessing technique for digital hearing aid

Abstract

This paper deals with a single-channel speech enhancement algorithm, preprocessed using partial differential equation, used to overcome degradation of noisy speech signals in digital hearing aids. Adaptive threshold is estimated using variance in time index. Gain is modified based on adaptive threshold estimated in frequency bins and used to enhance noisy signal. By proposed method, definite improvement in SNR and reduced MSE can be obtained compared to conventional method. This method provides a greater degree of flexibility and control on noise subtraction levels that reduce artifacts in enhanced speech, resulting in improved speech quality and intelligibility.