We propose a new approach to improve the performance of speech enhancement techniques based on wavelet thresholding. First, space-adaptation of the threshold is obtained by extending the principle of the level-dependent threshold to the Wavelet Packet Transform (WPT). Next, the time-adaptation is introduced using the Teager Energy Operator (TEO) of the wavelets coefficients. Finally, the time-space adapted threshold is proposed. Comparisons with the Ephraim and Malah Filter are reported.