Comparative study of different parameters for temporal decomposition based speech coding
Temporal decomposition (TD) is an effective technique to compress the spectral information of speech through orthogonalization of the matrix of spectral parameters leading to an efficient rate reduction in speech coding applications. The performance of TD is a function of the parameters used. Although "decomposition suitability" of a parameter set is typically defined on the basis of "phonetic relevance" criterion, it can not be directly used in speech coding. Instead, quality evaluation of reconstructed speech is more appropriate. In this paper, we extend our earlier work in this area and attempt to assess several "popular" spectral parameter sets from the viewpoint of decomposition suitability in very low bit-rate speech coding using parametric, perceptually-based spectral, and energy distance measures.