METHOD AND DEVICE FOR DETECTING RISE AND FALL OF SOUND SIGNAL, PROGRAM, AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To accurately detect a sound signal rising and falling with a small operation quantity and a small processing quantity. SOLUTION: An inputted sound signal is divided into analytic frames, which are each subdivided into sections; and the energy of the sound signal in each section is calculated and a straight line or curve approximating variation of energy of multiple sections is calculated. Then the difference between a value approximated by the straight line or curve, section by section, and the energy of the sound signal is calculated and the value obtained by adding the absolute value or squared value of the difference by multiple sections is compared with a previously set threshold to detect rise and fall of the sound signal in the analytic frames.