I am no doctor, but I wouldn't advise you take any medication to help you sleep that wasn't manufactured specifically for helping you to sleep. Summer of last year I went airboating on the Everglades and the instructors gave us these foam ear plugs that were supposed to block out a lot of the sound from the huge engine behind us. Guess what, it worked. Why don't you get yourself a pair of foam ear plugs. They are light and aren't noticeable after a while. That should solve your problem.
On the other hand, if you are into that kind of thing, then I would suggest not bothering with 'Gravol', but get yourself some Valium instead. Pop one of those and you will have a good sleep :p