We propose in this paper a new strategy for non-stationary signals denoising based on designing a time-varying filter ada-pted to the signal short term spectral characteristics. The basic idea leading us to use a new parametric nonlinear weighting of the measured signal short term spectral amplitude (STSA) is exposed. The overall system consists in combining the estimated STSA and the complex exponential of the noisy phase. The proposed technique results in a significant reduction of the noise for a variety of non-stationary signals including speech signals.