METHOD AND DEVICE FOR ACCENTUATING PITCH

摘要

PROBLEM TO BE SOLVED: To enhance hearing quality by enabling a low-bit-rate voice encoder/ decoder to accentuate pitches at a higher degree of accentuation without decreasing the naturalness of decoded voices. SOLUTION: A residual signal is first calculated from a decoded voice by an LPC reverse filter 301, and a first lag value T1 is calculated by a first lag value calculating part 302 by use of the residual signal r(n). Next, a second lag value T2 is calculated by a second lag value calculating part 303. The second lag value T2 is calculated as a lag value obtained when the correlated value of the residual signal or its associated value is maximized within a range including decimal lag values around either the first lag value T1 or a lag value twice the integer part thereof. The decoded voice is passed through a pitch accentuating filter at signal waveforms available at the first and second lag values.