The well-tempered conversation: interactivity, delay and perceptual VoIP quality

Abstract

The factors causing perceptual quality impairment on voice-over-IP (VoIP) connections include traditional network quality-of-service (QoS) parameters like packet loss rate, delay or jitter as well as parameters characterizing the conversation itself. Among the latter ones, we focus on the impact of "conversational interactivity" on the perceptual quality of a phone conversation. We introduce "parametric conversation analysis" as a formal framework for the instrumental investigation of conversational parameters at different transmission delay conditions, we further present the notion of "conversational temperature" as an intuitive scalar metric for the interactivity of conversations, and we demonstrate the application of our methods to a set of conversation recordings performed under various delay conditions, also with respect to results of subjective quality ratings.