I am extremely sensitive to noise too. I work with someone in a VERY tiny office who loves to hear himself talk, while I sit there and try to figure out a polite way to say, SHUT UPPPPPPP!!!! Best thing I've found is headphones. In extreme cases, getting up and standing outside for a bit works.

It's also very noisy where I live right around when I'm trying to go to sleep most nights. (My immediate neighbor and one across the alley both work nights, and one drives a motorcycle and one has to load up lots of boxes!) In that case, I try to put on some relaxing music and grit my teeth, LOL -- because even if I manage to fall asleep before either of them zooms off, the noise of the one banging the garage door closed or the other revving his bike will require me to be peeled from the ceiling.

I don't know what else to suggest. Earplugs, maybe? You can get them cheap at most drugstores.