关键词: 助听器, 维纳滤波, 先验信噪比, 噪声谱估计

Abstract: Wiener filtering algorithm is one of the commonly used algorithms to improve the speech intelligibility of hearing impaired patients in the noise environment. In this paper, in order to solve the large deviation problem in the noise spectrum estimation of traditional Wiener filtering algorithm, one speech noise reduction algorithm based on the improved multi-channel Wiener filtering is proposed. Firstly, with the features of human auditory and hearing aid loudness compensation, the speech signal will be decomposed into multi-sub-band signals by the Gammatone filter. Then the Wiener filter based on a priori SNR estimation is used for speech enhancement in each sub-band. Finally, the sub-band signals are integrated to get the enhanced speech. Furthermore, a voice activity detection algorithm based on the envelope estimate is proposed to improve the problem in the noise spectrum estimation of traditional Wiener filtering algorithm. And it is also used to improve the performance of the Wiener filter. Experimental results show that, compared with the traditional Wiener filtering, the proposed method can more effectively suppress the residual noise and improve speech intelligibility, which has high practical value.

Key words: hearing aid, Wiener filtering, priori Signal to Noise Ratio（SNR）, noise spectrum estimation