Speech Enhancement Based On Wavelet Transformation

Speech signal is the most convenient and shortcut way of intercommun -ion. However, in the course of the intercommunion, speech signal is disturbed and polluted inevitably by surroundings and transmission mediums. At the same time,it also influences the other transact processing of speech signal,for example,speech identification,speech code and so on.so it is important to denoise for the speech signal.In the past,we enhance the speech signal by the traditional methods,including spectral subtraction,harmonic enhancement and so on, they are effective.But they are not content when the signal contains the white noise. Wavelet transform is a very popular method in the processing of digital signal nowadays,it is applied popularly in fact and plays a more important role in speech processing.This paper mainly presents the research of the speech denosing based on wavelet transform. Firstly, we introduce the basis of speech processing,the basic theory of wavelet, methods of signal denosing based wavelet transform and application of denosing methods in speech.In speech signal,because of the different character of surd and sonant,it is important to distinguish them,the paper puts forward the combined parameter algorithm,it is the basis of the latter process.Recently in the signal denosing domain more and more methods based wavelet are used to reduce the noise . In these algorithms ,hard threshold method and soft threshold method are mostly included. Now we present a new method based hard threshold and soft threshold methods. Lastly, Experiment results demonstrate that the method is effective and excellent.