Wavelet for speech denoising

Abstract

This paper presents the use of the wavelet transform for noise reduction in noisy speech signals. The use of different wavelets and different orders have been evaluated for their suitability as a transform for speech noise removal. The wavelets evaluated are the biorthogonal wavelets, Daubechies wavelets, coiflets as well as symlets. Also two different means of filtering the noise in the transformed coefficients are presented. The first method is based on magnitude subtraction while the second method is based on the Wiener filter with a priori signal to noise ratio estimation.