SOUND SIGNAL FILTER, ITS FILTERING METHOD, ITS PROGRAM AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To perform operation in a frequency domain, the operation being equivalent to the operation for convoluting a finite length impulse response filter longer than an analysis window length, into a sound signal in time domain. SOLUTION: A cyclic time shift operation section of a sound signal filter generates a frequency filter by multiplying a cyclic time shift operator by a frame sequence of a frequency filter in which short time Fourier transformation of each frame of a frame length M of the finite length impulse response filter coefficient in time domain is performed by a point number Np. A convolution operation section generates a vector collecting all frequency bins by convoluting the frequency filter by each frequency bin of a frequency sound signal in which short time Fourier transformation of each frame of a frame length M+N-1 of a discrete valued time domain sound signal is performed by the point number Np. A window function adaptation section generates a frequency domain output signal by multiplying the vector collecting all frequency bins, by a cyclic convolution matrix which has a short Fourier transform vale of the window function at a first row. COPYRIGHT: (C)2009,JPO&INPIT