On speech quality estimation of phase-aware single-channel speech enhancement

Abstract

To approximate the speech quality of a given speech enhancement system, most of the existing instrumental metrics rely on the calculation of a distortion metric defined between the clean reference signal and the enhanced signal in the spectral amplitude domain. Several recent studies have demonstrated the effectiveness of employing a phase modification stage in single-channel speech enhancement showing positive impact brought by modifying both amplitude and phase in contrast to the conventional methods where the noisy spectral amplitude is only modified and noisy phase is used for signal reconstruction. In this work we present two contributions; First we study the reliability of the existing instrumental metrics for performance evaluation of phase-aware methods, and second we propose novel phase-aware instrumental metrics and evaluate their reliability in terms of predicting the perceived quality achieved by the phase-aware methods. Our objective and subjective evaluations demonstrate that PESQ and the proposed phase deviation metric perform as reliable speech quality estimators following the subjective results.