Anticipation of turn-switching in auditory-visual dialogs

This paper presents an experiment in which we examined whether German and Australian English perceivers were able to predict imminent turn-switching in Australian English auditory-visual dialogs. Subjects were presented excerpts of one and four second duration either preceding a switch or taken from inside a turn and had to decide which condition they saw. Stimuli were either A/V, video-only or audio-only. Results on the one second excerpts were close to random. In general we found a preference for non-switching. Australian subjects outperformed the German subjects in the audio-only condition, but outcomes were almost equal on the A/V stimuli. Analysis regarding the syntactic and prosodic properties of the stimuli showed that phrase-final statement as well as question intonation facilitated recognition presumably due to these acting as markers of turn-switch preparation; whereas incomplete sentences and non-terminal intonation were indicative of turn-internal excerpts. As to visual cues signaling a following switch results were rather varied. An open mouth on the part of the listener more often preceded switches than not.