Explicit estimation of magnitude and phase spectra in parallel for high-quality speech enhancement.

Journal: Neural networks : the official journal of the International Neural Network Society
Published Date:

Abstract

Phase information has a significant impact on speech perceptual quality and intelligibility. However, existing speech enhancement methods encounter limitations in explicit phase estimation due to the non-structural nature and wrapping characteristics of the phase, leading to a bottleneck in enhanced speech quality. To overcome the above issue, in this paper, we proposed MP-SENet, a novel Speech Enhancement Network that explicitly enhances Magnitude and Phase spectra in parallel. The proposed MP-SENet comprises a Transformer-embedded encoder-decoder architecture. The encoder aims to encode the input distorted magnitude and phase spectra into time-frequency representations, which are further fed into time-frequency Transformers for alternatively capturing time and frequency dependencies. The decoder comprises a magnitude mask decoder and a phase decoder, directly enhancing magnitude and wrapped phase spectra by incorporating a magnitude masking architecture and a phase parallel estimation architecture, respectively. Multi-level loss functions explicitly defined on the magnitude spectra, wrapped phase spectra, and short-time complex spectra are adopted to jointly train the MP-SENet model. A metric discriminator is further employed to compensate for the incomplete correlation between these losses and human auditory perception. Experimental results demonstrate that our proposed MP-SENet achieves state-of-the-art performance across multiple speech enhancement tasks, including speech denoising, dereverberation, and bandwidth extension. Compared to existing phase-aware speech enhancement methods, it further mitigates the compensation effect between the magnitude and phase by explicit phase estimation, elevating the perceptual quality of enhanced speech. Remarkably, for the speech denoising task, the proposed MP-SENet yields a PESQ of 3.60 on the VoiceBank+DEMAND dataset and 3.62 on the DNS challenge dataset.

Authors

  • Ye-Xin Lu
    National Engineering Research Center of Speech and Language Information Processing, University of Science and Technology of China, Hefei, China. Electronic address: yxlu0102@mail.ustc.edu.cn.
  • Yang Ai
    National Engineering Research Center of Speech and Language Information Processing, University of Science and Technology of China, Hefei, China. Electronic address: yangai@ustc.edu.cn.
  • Zhen-Hua Ling
    National Engineering Laboratory for Speech and Language Information Processing, University of Science and Technology of China, 443 Huangshan Road, Hefei 230027, China.