does the current way you experience sound not imply synesthesia?
if you're not looking at (or watching a recording of) someone playing an instrument, something making the sound, the sound you hear becomes acousmatic, as you don't see what's causing it. afaik the brain quickly tries to make up something on the spot.
of course, it's easier to make out what you're hearing if you ie. modify the playback speed of a tape recording.
the well known sound becomes it's warped, version scaled up or down. It
sounds bigger if you slow it down (bigger objects resonate with lower frequencies) and vice versa if you speed it up (smaller objects resonate with higher frequencies).
Obviously in case of dealing with more complex manipulations or purely synthesised, digitally processed sound the results are much harder to categorize by our brains, since how are you supposed to categorize something that sounds like a cat purring but it's very large and made of thick rubber? ever seen something like that?
I think it actually could push creative cgi forward quite a bit if we were to visualize sounds we're quite used to in music.
ie. if you just modeled it after the timbre and so on, which is a possibility, since
it's possible to do in reverse with human voice.
I think music visuals also do lack massively in that area.
Also, Ash Koosha is p cool when it comes to those audiovisual things, sound design wise, as above, objekt and mesh come to mind