对上述数据取一帧(512点), 进行fft变换, 对其模值取对数log后在图上标示(x轴为其频率, 要标注单位)出频谱曲线.-The above data in a frame (512 points), FFT transform, the modulus value after taking logarithm log marked on the diagram (x axis as its frequency, to indicate the unit) spectrum curve.