Uncertainty Evaluation of Objective Speech Quality Measurement in VoIP Systems

This paper deals with the measurement uncertainty of the speech quality (SQ) achievable by an actual voice-over-Internet-protocol (VoIP) telephony network. The accuracy of end-to-end speech data provided by the perceptual estimation of SQ (PESQ) algorithm suggested in the International Telecommunication Union (ITU) recommendation P.862 is discussed. Then, the uncertainty of the PESQ results under different measurement conditions and real-life VoIP equipment (media gateway) is analyzed. This problem, in fact, has received very little attention in the literature, although many results related to other kinds of PESQ applications are available. Meaningful experimental data are reported and discussed mainly by means of statistical tools.