I don't know if this counts as hyperarousal, but I find myself jumping a mile at things like microwaves pinging and door buzzers going off, even if I'm expecting them... What helps for me, though, is to have some form of background noise so the sound isn't quite so sudden and doesn't stand out as much (if that makes sense). I have the TV on in the kitchen and music playing on my laptop when I'm in my room, which seems to work pretty well.

Good luck, anyway, hope you can find something that helps.