给出一段噪声音乐信号，用滑动平均滤波器进行处理，观察改变滑动窗口宽度对声音效果的影响。　
（1）读取一段噪声信号，画出未处理噪声信号的时域波形和信号频谱图；
（2）在Matlab中利用滑动平均滤波器对噪声信号进行处理，得出处理后的图像；
（3）改变滑动窗口的宽度，观察处理后噪声以及图像得出对效果的影响。(A piece of noise music signal is given. It is processed with a sliding average filter to observe the effect of changing the width of sliding window to the sound effect.
(1) a noise signal is read and the time domain waveform and signal spectrum map of the unprocessed noise signal are drawn.
(2) in Matlab, a sliding mean filter is used to process the noise signal, and the image after processing is obtained.
(3) to change the width of the sliding window, to observe the noise after processing and to the effect of the image.)