A perceptually weighted speech coder system samples a speech signal and determines
its pitch. The speech signal is characterized as fully voiced, partially voiced
or weakly voiced. A Lloyd-Max quantizer is trained with the pitch values of those
speech signals characterized as being substantially fully voiced. The quantizer
quantizes the trained fully voiced pitch values and the pitch values of the non-fully
voiced speech signals. The quantizer can also quantize gain values in a similar
manner. Sampling is increased for fully-voice signals to improve coding accuracy.
This limits application to non-real time speech storage. Mixed excitation is used
to synthesize the speech signal