Speech enhancement based on Laplacian-Gaussian model and simplified phase discrimination in Discrete Cosine Transform domain

The relationship among the gain,a priori SNR and a posteriori SNR of noisy speech signal is analyzed in Discrete Cosine Transform domain.The statistical properties of the gains' range are obtained from the true data at several SNRs.The formulae of gain and a priori SNR dependent on the phase are derived employing the Laplacian model for speech and Gaussian model for noise.The simplification of the phase discrimination is obtained by analyzing the reasonability of the gain and a priori SNR.The experiment results indicate that the simplified phase discrimination achieves much improvement on the performance of speech enhancement at low SNR in white Gaussian noise and F16 jet noise.