Fourth European Conference on Speech Communication and Technology

Madrid, Spain
September 18-21, 1995

A New Very Low Bit Rate Speech Coder: The Step Decomposition Vocoder

Lorenzo Piazzo

INFOCOM. Dpt, University of Rome "La Sapienza", Rome, Italy

An extension of the classical LPC model of speech production is proposed, where the LPC spectral trajectories are viewed as the output of linear shift-invariant filters (articulator filters: representing the articulator responses to a brain command), excited by piece-wise constant signals (command signals: representing brain commands). Efficient procedures for the articulator filters estimation and for the command signals computation from the speech signal are outlined. The model is then used to design a very low bit rate, low computational burden vocoder, the Step Decomposition Vocoder, from which comprehensible speech can be obtained with about 650 bps, and with a 250 millisec. algorithmic delay.

Full Paper

Bibliographic reference.  Piazzo, Lorenzo (1995): "A new very low bit rate speech coder: the step decomposition vocoder", In EUROSPEECH-1995, 237-240.