The Ventriloquist Illusion in Audiovisual Virtual Reality
The ventriloquism effect is a well-studied example demonstrating how vision can affect sound perception. Although this effect can be demonstrated by simple means in laboratory environments real world implementations of more complex scenarios may suffer from trial-to-trial variability and a lack of reproducibility. Using virtual reality technology these issues can be circumvented by decoupling auditory from visual stimulation allowing to introduce inconsistencies between both sensory modalities. However, the limitations of head mounted displays and spatial sound reproduction may affect audiovisual perception resulting in, for example, an overestimation of ventriloquism due to the spatial blur of spatial sound reproduction. Therefore, an experiment is carried out utilizing various (loudspeaker-based) spatial sound reproduction methods and a head-mounted display. Participants are presented with synchronous audiovisual stimuli exhibiting a range of azimuth offsets in the horizontal plane while fixating a visual marker. The location of the acoustic stimulus is reported without the constraint of fixation.