How ​Music Proves We Live In Three Dimensions
String theory has dimensions popping up all over the place. We are currently at over 10 dimensions. But how would living in that many dimensions affect us? The first thing to do would be to throw out all your albums, because they won't sound right anymore.
Three dimensions are convenient for sound waves. They begin and end at distinct times, they gradually get softer as they travel outwards, and we are able to hear where they are coming from, because the sound changes when moving the small distance between our two ears. That wouldn't be so in two dimensions. Sound waves wouldn't fade away as they move through two dimensional space. Instead of vibrations, a sharp sound would start a kind of moving hill that would spread out in space and time. We would hear sound, but we wouldn't be able to judge where it came from or when it started. In one dimension, there would be no fading of sound whatsoever. Every sound would keep traveling with almost no fade-out. You could be deafened by a loud noise that happened a mile away.
In four dimensions, sound fades as it does in this universe, but while it lasts, it's very different. Sound gets stretched and reverberated. There is no such thing as a clean sound, or a single sudden note in the fourth dimension. (Or, if there is, it doesn't come from the phenomenon we understand to be sound.) Listening to even simple tunes – like chopsticks – would be like listening to many people playing them, all starting at slightly different times and overlapping each other. On the other hand, it's possible that in the fourth dimension that you could sing a round with yourself. That would be an interesting challenge for a songwriter.