JPS647710A - Channel filter - Google Patents

Abstract

PURPOSE:To reduce an arithmetic quantity by setting freely the window time of a DFT and executing an arithmetic mean of a BPF group output in the channel filter of a BPF group to execute the discrete Fourier transformation (DFT) of a band divided sound signal and obtain a spectrum component. CONSTITUTION:A window time setting part 3 is provided at a channel filter, a window time in a DFT arithmetic part 2 of a sound input signal temporarily stored in a register 1 is changed in accordance with the band width and the spectrum component of the BPF output of the band divided sound signal is calculated and outputted. When the band width is wide, the output of plural BPF groups is processed and outputted by an arithmetic mean arithmetic part 5. Thus, by the constitution in which a secondary single peak digital filter to need rectification is not necessary, and an arithmetic quantity is simple and small, the channel filter of the characteristic equal to the secondary single peak digital filter is obtained.