| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an audio signal processor capable of suppressing noise of a frequency in which an audio signal component of low frequency range does not exist. <P>SOLUTION: The audio signal processor comprises an LPF (low pass filter) for passing a first low frequency range of an audio signal, an FFT (fast fourier transform) for carrying out fast Fourier transform of the audio signal of the first low frequency range, an extractor for extracting a fundamental tone frequency from frequency components of the first low frequency range, a calculator for calculating a harmonic tone frequency from the fundamental tone frequency, a second LPF for passing an audio signal of a second low frequency range which makes a frequency higher than the highest frequency of the first low frequency range as its highest frequency, an FFT for carrying out fast Fourier transform of the audio signal of the second low frequency range, a frequency determination for determining a fundamental tone frequency and a harmonic tone frequency from frequency components of the second low frequency range, and a filter for amplifying the audio signal based on the determined frequencies and an inputted amount of amplification. <P>COPYRIGHT: (C)2007,JPO&INPIT |
