This paper presents a two-stage soft thresholding algorithm based on discrete cosine transform (DCT) and empirical mode\ndecomposition (EMD). In the first stage, noisy speech is decomposed into eight frequency bands and a specific noise variance\nis calculated for each one. Based on this variance, each band is denoised using soft thresholding in DCT domain. The remaining\nnoise is eliminated in the second stage through a time domain soft thresholding strategy adapted to the intrinsic mode functions\n(IMFs) derived by applying EMD on the signal obtained from the first stage processing. Significantly better SNR improvement and\nperceptual speech quality results for different noise types prove the superiority of the proposed algorithm over recently reported\ntechniques.
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