"Our consciousness lags 80 milliseconds behind actual events...The 80-millisecond rule plays all sorts of perceptual tricks on us. As long as a hand-clapper is less than 30 meters away, you hear and see the clap happen together. But beyond this distance, the sound arrives more than 80 milliseconds later than the light, and the brain no longer matches sight and sound. What is weird is that the transition is abrupt: by taking a single step away from you, the hand-clapper goes from in sync to out of sync." source
This made me curious - say we have the following experiment based on the above:
- A subject (listening subject) wears headphones synchronized with the hand-clapper
- the hand-clapper starts from 5 meters away and slowly moves to 60 meters away
- during this time, the listening subject would hear a clapping sound as they would naturally hear the sound based on the distance of the hand-clapper
If, once the hand-clapper reaches 60 meters, the audio is tweaked such that the listening subject would hear the hand-clapping sound as if the hand-clapper were only 5 meters away:
Would your typical listening subject visually perceive the hand-clapper as having suddenly moved closer (similar to the concept of how we perceive the moon as being "larger" when it's closer to the horizon)?
In other words -- under what circumstances, if any, can sound influence our visual perception of depth/proximity?