Very low data rate speech compression with LPC vector and matrix quantization

Frame predictive vector quantization is developed to compress the bit rate for coding the LPC filter coefficients to under 250 bits/sec. An innovative LPC compression technique, matrix quantization, is also developed to compress the LPC filter coefficients to a rate under 150 bits/sec. Subjective evaluation with the diagnostic rhyme test (DRT) finds the proposed techniques to be feasible for intelligible speech transmission at bit rates between 400 bits/sec and 200 bits/sec.