制一段个人自己的语音信号，并画出该信号的时域波形和频谱图；再录制一段同样长时间的背景噪声叠加（加法叠加）到语音信号中，分析叠加前后信号频谱的变化；设计一个合适的滤波器，把改造生滤除；最后回放语音信号。(peech signal processing for a period of one's own, and draw the signal time-domain waveform and frequency spectrum; background noise superimposed and recorded an equally long time (addition addition) to the speech signal analysis, signal spectrum changes before and after stacking; design a suitable filter, the filter finally return voice transformation of students; signal.)