| 摘要 |
PROBLEM TO BE SOLVED: To accurately find a pitch cycle fast with inexpensive constitution even when a speech waveform is a complicated waveform containing an overtone component. SOLUTION: A binarization part 8 and a timer 9 find and store successive zero-crossing intervals of a digital speech signal supplied from the precedent stage. A pitch arithmetic part 11 assumes that a pitch cycle is the sum 2n pieces of zero-crossing interval data as to n=1-4, calculates a reproduction rate as the degree of matching in each pitch cycle of each zero-crossing interval data constituting one pitch cycle, and employs the assumption by which the highest reproduction rate is obtained to find the pitch cycle. |
