Escapee.

I was coming home on the train lastnight and was standing in the aisle listening to my music. Out of nowhere I felt a sudden ripple in my arsehole as some elusive gas escaped from my hole. Shit, did I make a noise? I had my headphones in and a guy's head was at my arse level. I pretended like nothing happened in the hope I hadn't made a huge noise. No one I was facing seemed to notice anything, but I was too afraid to turn around. What was the point...

Which brings me to my next quandry. How does a deaf person know their fart isn't going to make a noise? It's why no one's ever heard a deaf person fart. Think about it, it's true...