Yep...certain noises are a trigger for me too.

One of the best tips I got for this was here on this forum. I keep my ipod with me at all times and have headphones with it. I find that turning that on (I have a particular playlist set up for these moments) with the headphones in does wonders for me. I had tried listening to music before...through speakers...but it's the headphones that make the difference. Some situations where this helps a lot are when someone is running a vaccuum (that noise just KILLS me), when they were doing roadwork outside our house, when my boyfriend mows the lawn, when there's some sort of high pitched noise that I can't pinpoint or can't turn of...stuff like that. This doesn't help for those quick noises that will give me a jolt...but helps with the ones that go on for a while.