先产生三个不同的信号，一个为正常录音，一个为环境噪声，一个不同频段的matlab信号，信号叠加之后分别用IIR和FIR滤波器提取正常声音信号。-First produce three different signals, one for the normal recording, one for the ambient noise, a different frequency band of the matlab signal, respectively, after the signal wi