I've had a mood disorder since a teen and I've had periods where I am super-sensitive to all noises and it makes me extremely agitated. I don't think it necessarily means that you have a mental disorder. I've also played the guitar since a teen and I can pick up subtle differences and nuances in tone, timbre and other audio that others can't. But the super-sensitivity to noise can really drive you crazy. I heard an interview with a rock drummer and he said that he unconsciously picks up rhythms in all sorts of things like raindrops.