Constant delay and rate coding of speech spectral envelope at 11 bits/frame
E. Yakhnich, Y. Bistritz · 2003
Parametric vocoders are used to attain very low rate compression. A new method for segment coding of a speech spectral envelope is proposed, based on coding of constant length segments. It is a computationally efficient method for LPC (linear predictive coding) parameter coding based on TD (temporal decomposition). It attains average LSD (log-spectrum distortion) less than 1 dB at 11 bits/frame. Thus, it saves 56% of the LPC parameter bit budget which is 26% of the total NELP2400 vocoder bit budget. The method offers constant delay and relatively low complexity.