Quantization of the spectral envelope for sinusoidal coders

In an effort to efficiently code the spectral envelope of speech signals for wideband speech coding based on sinusoidal models, a robust computation of discrete cepstrum coefficients and their quantization is investigated. A parameterization of the spectral envelope has been proposed which is based on discrete cepstral coefficients using regularization techniques. This paper presents an efficient quantization scheme for these coefficients in order to use them in applications like speech coding. We present results which show a 35% reduction in bitrate when compare to simple scalar quantization. To verify the efficiency of the proposed quantization schemes, informal listening tests were performed in the context of a sinusoidal coder.