抄録
A de-noising using a Wavelet Packet transform is described. An optimum threshold for de-noising was obtained. A new selecting method of a transform level and an order of the wavelet function is also proposed. For the threshold of an adaptive de-noising. the noise estimated from the speech signals was used. The estimated noise was proportional to the optimum threshold. The other two de-noising methods were compared. The proposed method has the most prominent property among the three methods.