Timers for the individual showers? Someone mentioned that on here awhile ago. However, is there a need for white noise in that particular room or any room? If so, maybe getting one of those machines with sounds (like waterfalls, if that's what they were trying to recreate).
I thought we had that last week. It seemed like I heard water running for a very long time. Turns out all 4 occupants of the room wanted to shower one after the other, so the water WAS running, but it least it was being used. 2 hours is a long time, tho!.
If so, maybe getting one of those machines with sounds (like waterfalls, if that's what they were trying to recreate).
We just got a great white noise generator (after trying a few that we ended up not liking) for bwirt's room. The Sound Sleeper
is pretty inexpensive but has great sounds to it. waves, stream, rain, thunder storms, birds... And you can layer the sounds on top of each other so you can have waves with a thunderstorm. The one wierd sound is the buoy-gong, I mean it makes sense layering on top of the waves, but I can't imagine trying to sleep with that clanging every so often.