程序利用小波分解将声音信号分解为高频与低频部分，而后利用软阈值方法确定高频与低频各自的小波重构系数，将高频与低频部分重构还原信号达到降噪的目的。-Program using wavelet decomposition sound signal into high and low parts, then use soft threshold method to determine the high and low frequency coefficients of each wavelet reconstruction, reconstruction of the high and low frequency part of the purpose of noise reduction signal reaches.