AUDIO SIGNAL TRANSFORM DEVICE, METHOD, PROGRAM, AND RECORDING MEDIUM

摘要

The present invention transforms an audio signal capable of providing a suitable audio image when playing back an input audio signal of 3 channels using a speaker group with such a playback method as a wavefront synthesis playback method. An audio signal transform device of the present invention (illustrated as an audio signal processing unit (63)) is provided with: a correlation signal extraction unit (72b) for extracting a correlation signal after applying discrete Fourier transform to 2 channels out of a 3-channel input audio signal; an inverse transform unit (72c) for applying inverse discrete Fourier transform to the extracted correlation signal or correlation signal and decorrelated signal, or audio signal generated from the correlation signal, or audio signal generated from the correlation signal and the decorrelated signal; and a summing unit (74a) for summing the remaining one-channel input audio signal with the audio signal after the inverse discrete Fourier transform. The correlation signal extraction unit (72b) varies a coefficient of the correlation according to the correlation between the 2-channel audio signal and the remaining one-channel input audio signal when calculating the correlation coefficient for the 2-channel audio signal.