中文说明：
（1）选取windows系统自带的ding.wav信号作为分析对象，在Matlab软件平台下，利用函数wavread对音频信号进行采样，记住采样频率和采样点数，听一下原始声音sound(y, fs, bits)。
（2）音频信号的频谱分析，先画出音频信号的时域波形；然后对音频号进行快速傅里叶变换fft(y,N)，N取32768，画出信号的频谱特性，加深对频谱特性的理解。
（3）根据频谱，反演时域特性，画出时域波形。寻找幅值最大的两个频率，此频率除以fft点数在乘以采样频率就是信号的主频，即可合成信号的时域图形，听一下声音。
（4）对原音频信号进行1024点的分段付立业分析meshgrid
（5）根据主要频线合成音频，并画出时域图形，试听合成效果。
（6）采用线性插值（linspace）和傅立业反变换(fliplr, ifft)分别合成音频，并画出时域图形，试听效果。
English Description：
(1) select the ding system at Windows. Wav signal as the analysis object, the Matlab software platform, use wavread function of the audio signal sampling, remember the sampling frequency and sampling points, listen to the original voice sound (y, fs, bits).(2) audio signal spectrum analysis, draw the first audio signal of time domain waveform;Then the audio, fast Fourier transform FFT (y, N), N take 32768, draw the signal spectrum features, to deepen understanding of the frequency spectrum characteristics.(3) according to the frequency spectrum, inversion of time-domain characteristics, draw the time domain waveform.Looking for amplitude of the two biggest frequency, the frequency divided by FFT points in multiplied by the sampling frequency is the frequency of signal, can be synthesized signal time domain graph, listen to the voice.(4) of the original audio signal is 1024 points of segmented FuLiYe analysis meshgrid (5) the synthesis of audio frequency according to the main line, and draw the time-domain graphics, audition synthesis effect.(6) using a linear interpolation (linspace) and Fu Liye inverse transform (fliplr, ifft) synthetic audio respectively, and draw the time-domain graphics, audio-visual effect.