Speech enhancement of color noise using empirical mode decomposition

This paper introduces a new speech enhancement algorithm, which is efficient for color noises such as pink and babble noises. The algorithm applies the minimum variance estimator (MVE) into each intrinsic mode function (IMF) obtained by the empirical mode decomposition (EMD). Typical signal subspace approaches to speech enhancement assume the corrupting noise is white, thereby making a pre-whitening step mandatory when faced with various color noises. The algorithm presented in this paper is applicable into color noises, such as pink and babble noises, without the need to apply the whitening process. This is a result of the noises' variances in each IMF signal showing smaller fluctuations than without the application of the EMD. Experimental data demonstrates the effectiveness of the algorithm to combat color noises.