A New Method of Objective Speech Quality Assessment in Communication System

Abstract

On the Quality of Experience (QoE) evaluation of communication system, the quality of speech is an important factor to evaluate the system. Perceptual evaluation of speech quality (PESQ) is a well known objective speech quality assessment method for the voice QoE evaluation. It is proposed by International Telecommunication Union (ITU) and is formed as the ITU-T P.862 Recommendations. PESQ applies Bark-scale frequency to evaluate the Mean Opinion Score (MOS) for speech quality of voice communication system. But through our research, we find that the PESQ algorithm has limitations for evaluating speech quality. In order to change these limitations, this paper proposes a new objective evaluation algorithm by using ERB-scale to take the place of Bark-scale frequency. The ERB-scale is more accurate than Bark-scale to describe the frequency selectivity of the human ear when frequency at lower domain. We call the new algorithm as NPESQ (New Perceptual Evaluation of Speech Quality) whose accuracy is tested in our experiment. Through experimental comparison against PESQ and NPESQ, the results demonstrate the improvement of the NPESQ. Therefore, it can be concluded that the new algorithm can improve the accuracy of the measurement.