Exploiting Conjugate Symmetry of the Short-Time Fourier Spectrum for Speech Enhancement
Kamil Wójcicki, Mitar Milacic, Anthony P. Stark, James Lyons, Kuldip K. Paliwal · IEEE Signal Processing Letters · 2008
Typical speech enhancement algorithms operate on the short-time magnitude spectrum, while keeping the short-time phase spectrum unchanged for synthesis. We propose a novel approach where the noisy magnitude spectrum is recombined with a changed phase spectrum to produce a modified complex spectrum. During synthesis, the low energy components of the modified complex spectrum cancel out more than the high energy components, thus reducing background noise. Using objective speech quality measures, informal subjective listening tests and spectrogram analysis, we show that the proposed method results in improved speech quality.