SPEECH CODING APPARATUS

摘要

A speech coding apparatus in which a short term prediction parameter is extracted from an inputted a speech signal and an optimum code vector is searched in a code book minimizing an evaluation function with an auto-correlation functions of a speech source and an impulse response of a synthesis filter generated with the short term parameter to transmit an index of a decided code vector and a gain combined with a spectrum parameter and a pitch parameter is constituted such that the auto-correlations are calculated with an approximation order set to a value of an Ismall being less than the length of the impulse response of the synthesis filter to redcuce the quantity of product and sum operations.