Speech encoding and decoding method and apparatus therefor

摘要

A speech encoding method using a codebook (18, 19) expressing speech parameters within a predetermined search range, including analyzing an input speech signal in an audibility weighting filter corresponding to a pitch period longer than the search range of the codebook, and searching, from the codebook, on the basis of the analysis result, a combination of speech parameters by which the distortion of the input speech signal is minimized, and encoding the combination.