Speech coding apparatus, speech decoding apparatus, speech coding and decoding method and a phase amplitude characteristic extracting apparatus for carrying out the method

摘要

A speech coding and decoding apparatus for improving the quality of synthesized speech. A coding portion (1) includes a filter (30) for adding a short-term phase amplitude characteristic to an excitation signal, and a coding circuit (29) for quantizing and coding a phase amplitude characteristic. A decoding portion (2) includes a decoding circuit (31) for decoding the coded phase amplitude characteristic, and a filter (32) for adding the same phase amplitude characteristic as that in the coding portion. Thus, it is possible to synthesize high-quality speech with good reproducibility of the phase amplitude characteristic of an excitation signal.