On improving performance of analysis by synthesis speech coders

An algorithm for improving the performance of analysis-by-synthesis (A-by-S) speech coders is presented. It is shown that proper modifications of the A-by-S strategies commonly used to determine the excitation parameters can be devised. In particular, a redefinition of the classical objective function based on the weighted mean squared error criterion may allow a better tracking of the speech signal transients as well as a better alignment of the synthetic pitch pulses. The implementation details of the algorithm are discussed and experimental results are presented.