The importance of phase in speech enhancement

Typical speech enhancement methods, based on the short-time Fourier analysis-modification-synthesis (AMS) framework, modify only the magnitude spectrum and keep the phase spectrum unchanged. In this paper our aim is to show that by modifying the phase spectrum in the enhancement process the quality of the resulting speech can be improved. For this we use analysis windows of 32 ms duration and investigate a number of approaches to phase spectrum computation. These include the use of matched or mismatched analysis windows for magnitude and phase spectra estimation during AMS processing, as well as the phase spectrum compensation (PSC) method. We consider four cases and conduct a series of objective and subjective experiments that examine the importance of the phase spectrum for speech quality in a systematic manner. In the first (oracle) case, our goal is to determine maximum speech quality improvements achievable when accurate phase spectrum estimates are available, but when no enhan...

• Type: Journal
• Year: 2011
• Where: SPEECH
• Authors: Kuldip K. Paliwal, Kamil K. Wójcicki, Benjamin J. Shannon
• Keywords: Analysis Window, Magnitude Spectrum, Phase Spectrum, Security Privacy, SPEECH 2011