Quality comparison of low complexity 4800 bps self excited and code excited vocoders

This paper presents a formal objective and subjective comparison of a number of LPC vocoders which operate at bit rates around 4800 bps. In this work, particular emphasis is placed on the Self Excited Vocoder (SEV), a new speech coding approach which was introduced by the authors at ICASSP86 [1]. Many members of a class of LPC vocoders of which the SEV, the well known Multiple Pulse Excited Linear Predictive Coder (MPLPC) [2], and Code Excited Linear Predictive Coder (CELPC) [3] are members, are simulated and compared. Through these experiments, the SEV is shown to be a low complexity, simply implemented speech coder that is competitive with the other coders in this class in producing high quality speech at low bit rates.

[1]  Bishnu S. Atal,et al.  A new model of LPC excitation for producing natural-sounding speech at low bit rates , 1982, ICASSP.

[2]  Thomas P. Barnwell,et al.  The self excited vocoder - an alternate approach to toll quality at 4800 bps , 1986, ICASSP '86. IEEE International Conference on Acoustics, Speech, and Signal Processing.

[3]  Manfred R. Schroeder,et al.  Code-excited linear prediction(CELP): High-quality speech at very low bit rates , 1985, ICASSP '85. IEEE International Conference on Acoustics, Speech, and Signal Processing.