Light Location Influences the Perceived Locations of Internal Sounds

Numerous studies have shown that visual stimuli can bias the perceived location of auditory stimuli. Here, we sought to determine if a visual stimulus can also bias the perceived location of multiple internal auditory stimuli. Fifty subjects were presented with a train of eight binaural click-pairs over headphones while a single flash of light was presented either to the left or to the right side of a central fixation point on an otherwise black CRT screen. A no-flash baseline was also implemented, as was a no-fixation control. The subjects used a rating scale to indicate the perceived location of each of the eight click-pairs within their heads. The results showed that the flash of light significantly influenced the perceived location of the click-pairs, biasing them in the same direction as the flash of light. This suggests that, even without perceptual correspondence, cross-modal interactions can occur.