Phase and reverberation aware DNN for distant-talking speech enhancement

Abstract

Enhancing reverberant speech with Deep Neural Networks (DNNs) is an interesting yet challenging topic. The performance of speech enhancement degrades significantly when test and training conditions are mismatched. In this paper we propose a Static Reverberation Aware Training (SRAT)-based dereverberation through which the reverberation estimate is obtained by averaging over broken down frame. This method significantly reduces the input dimensions of the and enables the DNN to learn the relations between clean and reverberant speech more efficiently. Most speech enhancement approaches ignore phase information due to its complicated structure. As phase correlates closely to speech signal we exploited this relationship to achieve better performance using DNN. Phase information was augmented with magnitude information and used as the input for DNN. We denote this method as phase aware DNN. Finally, both phase information and reverberation were added to reverberant speech to achieve better speech enhancement performance in a distant-talking condition. Features of the reverberant speech, phase and reverberation were used during the training and testing stages. This is because the DNN could use both reverberation and phase information to better generalize the speech signal. The proposed method was evaluated using the REVERB CHALLENGE 2014 database. Results are significantly improved results with respect to both reconstructed speech quality (PESQ: Perceptual Evaluation of Speech Quality) and influence of reverberation (SRMR: Speech to Reverberation Modulation Energy Ratio). As compared to the conventional DNN-based approach, this proposed one improved SRMR from 4.84 to 5.92 and PESQ from 2.34 to 2.70, indicating that our proposed method could efficiently enhance speech severely corrupted by reverberation.