DIGITAL ACOUSTIC SIGNAL PROCESSING METHOD, DIGITAL ACOUSTIC SIGNAL PROCESSING APPARATUS AND DIGITAL ACOUSTIC SIGNAL PROCESSING PROGRAM

PROBLEM TO BE SOLVED: To output a digital acoustic signal having high sound quality and a sense of realism which has been lost when an analog acoustic signal is converted to a digital acoustic signal.SOLUTION: An adjustment amount calculation part 106 L divides an absolute value of a sample value of an Rch digital acoustic signal by an absolute value of a sample value of an Lch digital acoustic signal at a sample position generating a harmonic wave, sets the division result as an adjustment amount when the division result is less than 1.0, and outputs 1 as the adjustment amount when equal to or more than 1.0. A harmonic wave adjustment processing part 107 L multiplies variation for generating a harmonic wave from a harmonic wave variation processing part 103 L by the adjustment amount to generate a harmonic wave component after the adjustment processing of the Rch. An addition part 110 L adds, by the number of the samples corresponding to a time difference based on a sound path different between the Rch and the Lch, the Lch digital acoustic signal and the harmonic wave after the adjustment processing with sample positions thereof being relatively changed. The other channel is similarly processed.