Audiovisual tunnel effect

Recent researches demonstrate how auditory information can influence visual perception of events, for example how a simple sound affects visual event discriminations [Gerbino, 1997, in Human and Machine Perception Eds Cantoni et al (New York: Plenum Press) pp 147 ^ 154]. Here we present a case of a tunnel effect accompanied by a sound. We used the same values-length of trajectory for the moving object and length and width for the tunnel- as in Burke (1952 Quarterly Journal of Experimental Psychology 4 121^138) but we added a sound (220 Hz) accompanying the visual movement and a different speed - 25 mm s-1. The aim of our experiment was to demonstrate that a particular sound can influence the perceptual duration of the entrance^exit interval (EEI)-the duration for which the object is totally hidden by the screen. For this purpose we used five different between-subjects conditions: (i) a continuous sound (220 Hz) during the whole event; (ii) no sound under the tunnel; (iii) sound shifting up in frequency under the tunnel; (iv) sound shifting down in frequency under the tunnel; (v) no sound throughout. Results show the longest EEI for condition (iii), indicating that a particular kind of sound can influence the movement, although this is not a simple interference effect: EEI in (iv) is shorter than in (v). EEI is significantly shorter in condition (ii) than in conditions (i) and (v): this suggests that the absence of sound during EEI speeds up the amodal visual movement.