带通提取该频率信号，带阻是限制该频率信号。采样频率22050Hz，自己确定通带宽度，一般信号通带（或阻带）在200～300Hz，通带内衰减1db，过渡带在100～250Hz，阻带内衰减30db。-Bandpass frequency signal extracted with resistance is to limit the frequency of the signal. Sampling frequency 22050Hz, itself the passband width, gene