Evaluation of Wavelet-Based Speech Codecs for VoIP Applications

摘要

Wavelet-based speech coding, in general, offers a good degree of compression of the speech signal, whose magnitude can be varied easily. The Haar wavelet transform is the straight forward and fastest transform to be used for speech compression. However, due to its discontinuity, it is not advantageous for the simulation of speech signals. Daubechies wavelet has shown its superiority over other families of wavelet for speech compression in terms of all parameters such as % compression and SNR value and hence extensively used in various speech processing applications. Further, it can be inferred from the above that the average MOS of wavelet-based speech codec is in the range of 3.9-4.5, which is near toll quality; hence, they compare well with the currently deployed speech codec in the VoIP applications. The results further reveal that the performance of codec under study remains unaffected with change in language or speakers.