此文件实现了让语音信号通过低通，高通，带通滤波器使其变声，并且在GUI界面上绘出了个滤波器的频率响应和语音信号的频谱。-This file allows to achieve a voice signal through a low pass, high pass, band pass filter to make it change the sound, and plotted on a GUI interface and voice signal spectrum frequency response of a filter.