Does sound location influence audiovisual speech perception?
Poster Presentation

Kaisa Tiippana
Helsinki University of Technology

Riikka Möttönen

Hanna Puharinen

Mikko Sams

     Abstract ID Number: 50
     Full text: Not available
     Last modified: May 11, 2006
     Presentation date: 06/19/2006 4:00 PM in Hamilton Building, Foyer
     (View Schedule)

Abstract
Multisensory interactions are generally stronger when stimulation arises from a similar location in space. Surprisingly, for audiovisual speech this doesn’t seem to be the case. The McGurk effect, where conflicting visual speech alters the auditory speech percept, appears to be unaffected by spatial discrepancy between voice and face (e.g. Jones & Munhall, 1997). We hypothesized that allocation of spatial attention may be a factor, so that directing attention to a location would enhance audiovisual interactions there. Auditory attention was manipulated by varying the probability of auditory stimulus presentations from different locations (centre, i.e. face location, and 45/90 deg left/right). We replicated previous findings of independence of the McGurk effect of sound location in a condition where auditory stimuli were presented with equal probability from all locations. In another condition, attention was directed spatially by presenting the majority (90%) of auditory stimuli from one location. In Experiment 1, the major location was in the centre, which resulted in an enhanced McGurk effect there. In Experiment 2, the major location was 90 deg left, which resulted in a stronger McGurk effect on the left and centre relative to the right side. The results show that audiovisual speech perception can be influenced by sound location, and that this depends on the direction of spatial attention.