Modelling LPC-residue by components for good quality speech coding

A hybrid speech coding scheme is proposed based on the properties of the linear predictive coding (LPC)-residual. It is shown that the residual comprises characteristically different components, namely, high-energy pulses, a low-energy smooth component, and a random component. It is proposed that residue coding, as a composite of the respective functions corresponding to the components, is more effective and economical than the existing coding techniques which use only a single function to represent the entire residue. Results of simulating a hybrid coder with full quantization and also subjective evaluation of its performance are reported