经过语音信号短时谱分析，掌握短时傅里叶变换的定义，熟悉窗口形状、窗长对短时傅里叶变换的影响。 -After short-term spectrum of speech signal analysis, to grasp the definition of the short time Fourier transform, the familiar shape of the window, the window length on the short time Fourier transfor