通过计算分析输出信号的自相关函数利用基于自相关函数的方法来估计衰减系数和延迟，并利用快速傅里叶变换将回波信号滤除回声，得到原声音信号，同时根据延迟估计反射物的距离。-Analysis by calculating the autocorrelation function of the output signal utilizing the autocorrelation function based method to estimate the attenuation coefficient and a delay, and the use of fast Fourier transform to filter out the echo echo signals to obtain the original audio signal, while the delay of the estimated reflector distance.