Sometimes things like (the) hiccups can really bug people on a subconscious level.  I personally cannot stand when I hear people with breathing problems because it makes it hard for ME to breathe for some reason.  Once my nephew stayed over in my one bedroom apartment and slept on the couch.  From my bedroom I could hear him breathing, and his allergies caused his breathing to be laboured and uneven.  Sometimes he would even stop breathing for 5 or 10 seconds then start again with a bit of a snort.  This DROVE ME FREAKING CRAZY.  I felt like I was suffocating and could not sleep a wink.

In another case, my ex-girlfriend was showing me how to speak Slovak, and in that language there is a n' sound (which sounds sort of like 'nyeh')... well, whenever I said a word with that sound, I literally felt like I was drowning... it causes a muscle in my sinuses to contract that never does in my normal speech, and I think it is the same muscle that contracts when you are thrashing about in the water and getting a bunch up your nose... So after I say the sound in her language, I have to take a few deep breaths to convince myself that I am, indeed, not drowning and am on dry land...

Sorry, this reply was longer than expected and I don't even know if it satisfies my original intention, but it was so much typing I'm not about to delete any now...