Don't know if you still check this post, but I just read a article about sensory integration dysfunction. If your touchy child is extreamly sensitive you might want to ask your ped. about it.
I do know that my ds was the same and he seems to be growing out of it. I always "warn" him when I am about to turn on the blender or vacuum. I try to immitate the sound it is going to make. With the blender, I say "Julian zoooommm zoom zoommmm, and then do a silly booty shaking dance (while holding the top of the blender), which he thinks is pretty funny.
Once he figured out how to turn the vacuum off he was better with it. Good luck.
