METHOD AND APPARATUS FOR RECOGNITION OF PITCH

摘要

PROBLEM TO BE SOLVED: To simply and surely recognize a sound pitch of a high level signal generated from a musical instrument, etc., by detecting a pitch of a signal waveform in each zero-crossing area and using the detected pitch as an evaluation reference to select a zero cross to be evaluated. SOLUTION: A pitch of a signal waveform is detected in each zero-crossing area and the detected pitch is used as an evaluation reference to select a zero cross to be evaluated. An inputted signal waveform is filtered by a low-pass filter 2 through an A/D converter 1. The output of the low-pass filter 2 is inputted to a computing unit 3 constituted of a zero-cross detector 3a and a steepness computing element 3b. The zero cross detector 3a in the computing unit 3 detects the zero cross of the output of the low-pass filter 2 and the timing of the zero cross. The steepness computing unit 3b calculates steepness in the zero cross waveform at every zero crossing.