METHOD AND APPARATUS FOR ENHANCING PITCH

摘要

An LPC inverse filter (301) calculates a residual signal from a decoded sound. A first lag value calculating section (302) calculates a first lag value (T1) from the residual signal (r(n)), and a second lag value calculating section (303) calculates a second lag value (T2). The second lag value (T2) is calculated as a lag value for maximizing the correlation value of the residual value or a value concerning the correlation value in a range including the decimal parts over and below the first lag value (T1) or a lag value twice the integer part of the first lag value (T1). The decoded sound is subjected to pitch-emphasis filtering with the signal waveforms at the first and second lag values.