Enhancement of noisy speech using sliding discrete cosine transform

Abstract

Denoising of speech signals using a sliding discrete cosine transforms (DCT) is proposed. A minimum mean-square error (MMSE) estimator in the domain of a sliding DCT is derived. In order to provide speech processing in real time, a fast recursive algorithm for computing the sliding DCT is presented. The algorithm is based on a recursive relationship between three subsequent local DCT spectra. Extensive testing has shown that background noise in actual environment such as the helicopter cockpit can be made imperceptible by proper choice of suppression parameters. © Springer-Verlag Berlin Heidelberg 2003.