An experimental study on the phase importance in digital processing of speech signal

Abstract

This paper presents the results of a late large-scale subjective study of phase importance of speech quality. Present study includes a collection of speech sentences distorted by limited transmission bandwidth and phase degradations. A detailed statistical analysis of the collected subjective judgments is presented. Among the used signal distortions, subjects preferred modification with signal phase preservation. Mean opinion scores of such modification are the closest to the original, undistorted sentences. This subjective study contributes to improving the algorithms of the speech processing, and in addition provide valuable data to develop objective or automatic methods of speech quality assessment, as well as to estimate their performance.