I've had noise sensitivity too. Officially the diagnosis 'hyperacusis' (you can google it to see if it might be you as well), there are several different subtypes. One is misophonia. I forgot the rest. Different people may have different labels.
There can also be different causes for it. For me, what triggered it could be a combo of loud band practice I was at, contraception pills (I later found out they could have 'sensory' effects and could decrease amount of vitamins/minerals), nutritional deficiencies etc.

I've had it for a few years before being diagnosed with psyhosis/schizophrenia.
I linked it to poor myelin sheaths and nutritional deficiencies since it improved when I was taking magnesium/zinc tablets, though they had side effects, but I was just so happy that things improved. I then stopped eating supplements and started eating meat again (I was 75% vegetarian before) and things improved too.
Interestingly, schizophrenia has been linked to poor myelin sheaths too.

I still get annoyed by too loud noises (eg lawnmower or chainsaw) and have earmuffs and earplugs for that, in general it's best to use those as little as possible (the ears are more sensitive after the use of earplugs especially) and use your fingers when needed or leave to another room. I can sometimes tolerate the noises better (nutrition, weather, level of sleep etc) sometimes even the vacuum cleaner is okay, especially if I use it so that I control the noise, and not someone else.

It's been better since I've been on antipsychotics too (Zyprexa first, now Abilify). I've been taking fish oil too, this might be helping as well.