A CODEBOOK-BASED SPEECH ENHANCEMENT METHOD USING ADAPTIVE CODEVECTOR AND APPARATUS THEREOF

摘要

PURPOSE: A codebook-based speech enhancement method using an adaptive codevector and an apparatus thereof are provided to generate a super codebook by combining an existing noise codebook with adaptive codevectors that are generated through a long-term noise estimation, thereby guaranteeing performance on outside noises as well as on inside noises. CONSTITUTION: A speech enhancement apparatus estimates noise signals included in inputted speech signals using a long-term noise estimation algorithm and calculates a linear predictor parameter of the estimated noise signal (S360,S380). The speech enhancement apparatus generates a super codebook by saving N adaptive codevectors in a selected noise codebook (S400,S410). The speech enhancement apparatus outputs compensates speech signals using an integrated codevector, which is a combination of noise codevectors in the super codebook and clean codevectors in a clean codebook, and a spectral envelop value of the inputted speech signal (S420). [Reference numerals] (AA) Start; (BB) End; (S310) Input voice signals (y (n)); (S320) Generating a voice spectrum (y (k))^2 by Fourier conversion; (S330,S370) Fourier conversion; (S340) Extracting a linear estimation coefficient (a_y) of input voice signals (y (n)); (S350) Obtaining spectrum evelope value of input voice signals (y (n)); (S360) Estimating noise signals (d (n)); (S380) Extracting a linear estimation coefficient (a_d) of estimated noise signals (d (n)); (S390) Obtaining spectrum evelope value of estimated noise signals (d (n)); (S400) Selecting noise codebook having similar noise codevectors; (S410) Generating a super codebook by saving N adaptive codevectors in a selected noise codebook; (S420) Outputs compensated speech signals