PCT No. PCT/JP93/00776 Sec. 371 Date Feb. 9, 1995 Sec. 102(e) Date Feb. 9, 1995 PCT Filed Jun. 10, 1993 PCT Pub. No. WO94/29965 PCT Pub. Date Dec. 22, 1994There is provided a code excitation linear predictive (CELP) coding or decoding apparatus in which a code vector, which is transmitted by a codebook such as a stochastic codebook, is converted adaptively in accordance with vocal tract analysis information (LPC) so that a high quality reproduction speech is obtained at a low coding rate. Further, in order to obtain a similar effect, a pulse-like excitation codebook formed of an isolated impulse is provided in addition to the adaptive excitation codebook and stochastic excitation codebook so that either the stochastic excitation codebook or the pulse-like excitation codebook is selectively used to provide a vocal tract parameter as a linear spectrum pair parameter.
Code excitation linear predictive (CELP) encoder and decoder and code excitation linear predictive coding method