Strange... so strange to be seeing this question asked. As I sat outside on my deck smoking a cigarette I could hear the crickets SCREAMING! I wonder if that's what you mean? For me, it's not an hallucination because they REALLY are out there BUT they were definitely louder to ME than to anybody else, that I am sure of! When I am manic, I have super intense hearing. There is a name for it but I can't tell you now what it's called.

My dryer is on and it is SOOO loud. My washer is on and I can hear it through 2 walls. I hear my ceiling fan. I can hear (and I know how weird this sounds!) the lightbulb in the light above my head. It's like super-sonic hearing and it drives me nuts!

...and this we call the fine line between genius and insanity!