Principal axis extracting vector excitation coding: high quality speech at 8 kb/s. - Tomohiko Taniguchi; Yoshinori Tanaka; A. Sasama; Yasuji Ohta (ICASSP, 1990)

Multi-vector pitch-orthogonal LPC: quality speech with low complexity at rates between 4 and 8 kbps. - Tomohiko Taniguchi; Mark Johnson; Yasuji Ohta (ICSLP, 1990)

Pitch sharpening for perceptually improved CELP, and the sparse-delta codebook for reduced computation. - Tomohiko Taniguchi; Mark Johnson; Yasuji Ohta (ICASSP, 1991)

Tree-structured delta codebook for an efficient implementation of CELP. - Tomohiko Taniguchi; Yoshinori Tanaka; Yasuji Ohta (ICASSP, 1992)

Improved CELP speech coding at 4 kbit/s and below. - Tomohiko Taniguchi; Yoshinori Tanaka; Yasuji Ohta; Fumio Amano (ICSLP, 1992)