Scalar LPC quantization based on format JND´s

Efficient scalar quantization tables for LPC k-parameters were developed using a distortion measure based on just-noticeable-differences (JND´s) in formant parameters of the speech spectrum envelope. Forty percent fewer bits were required than the 41/frame used in conventional approaches. An empirical technique was developed for relating perturbations in k-parameters and formant parameters. New estimates were obtained for the values of the formant JND´s: they are about four times the steady-state values reported by Flanagan [6] and increase sharply above approximately 1.5 kHz.