Piecewise linear quantization of LPC reflection coefficients

We present a new quantization method for coding reflection coefficients in linear predictive coding (LPC) of speech. It employs piece-wise linear quantization and requires statistical properties of the LPC reflection coefficients. Although the quantization scheme is based on the density of the frequencies of the coefficient values, it does not neglect the importance of spectral sensitivity. In our informal subjective listening tests it was observed that the quality of synthetic speech with the transmission rate of 2.4 kbits/s coded by the piecewise linear quantization method was equivalent to the quality with the rate of 3 kbits/s coded by a linear quantization method.