A Wideband Speech Enhancement Method Based on Adaptive Noise Estimation

In order to improve the noise tracking ability and reduce the residual musical noise, an adaptive noise estimation method for wideband speech enhancement is proposed in this paper. The algorithm can be applied to wideband speech coder and improve encoding quality in noisy environment. The spectral entropy is adopted to classify the background noise into two categories, one for white noise, and the other for the colored noise. Then, appropriate noise estimation method is selected based on the noise characteristics. In white noise background, we choose a spectral smoothing method. In colored noise background, we utilize the minima-controlled recursive averaging algorithms. Finally, the proposed method is combined with the classical statistical model based speech enhancement, and the robustness to noise is improved evidently. The performance of the proposed method is evaluated under the standard of ITU-T G.160. The experimental results show that the algorithm is effective for improving the SNR in the different noise environments. Meanwhile, in low SNR conditions, musical noise is reduced effectively.