Abstract: In VoIP system, the performance of network transmission makes a fundamental impact on quality of experience. However, the traditional research based QoS can not be directly reflected to be Quality of Experience. We combined ITU PESQ and E-model algorithm and made a comprehensive analysis of the impact on user experience which was caused by packet loss, end-to-end delay, fitter, voice coding, and so on. Our contributions are thus twofold: firstly, we offered a detailed analysis of the impact of these parameters and their interactions on the perceived conversational quality.Secondly,we adopt regression model for singlccnded(nonintrusive) method for objective speech quality estimation according to different conditions. The experimental results show that the objective assessments are correlated well with objective assessments ones,which indicates that the method proposed here is effective.

Key words: QoS,Quality of experience,Objective assessment of speech cauality,Regression model