I think it makes sense that the higher your room is, the less noise there would be. I imagine the lower floors has car engine, baggage and chatting noises. Of course, the lower your floor is, the nearer you are to the lobby and parking area which amounts to all these noises mentioned. You can also add the outside noises out of the hotel which are the cars and construction sites if there are any.
If you can choose a room that's away from all these noises. This way, you can be ensured that your vacation will be a relaxing and calming one. You wouldn't want to be stressed out by such elements on your vacation.