Compression and enhancement of speech signals

Over the past several years there has been considerable attention focused on compression and enhancement of speech signals. This interest is progressed towards the development of new techniques capable of producing good quality speech at the output. Speech compression is a process of converting human speech into efficient encoded representations that can be decoded to produce a close approximation of the original signal. In this paper the simulated vocoder (LPC) using mat lab was implemented for compression. The result obtained from LPC was compared with other implemented speech compression using Wavelet transform in terms of quality. Speech enhancement means improving the quality or value of the signal in a noisy environment. In this paper we proposed spectral subtraction (S.S) and wavelet transform methods for denoising and the result of one method was compared with other. From the results we see that in both compression and enhancement, the performance of wavelet transform was better than other.