Lance,
Back to your original question and to expand on what Rick said, Correy got a bunch of recordings of different machinery running that were specific to a room or area. We don't play alarms or announcements unless it's for a specific reason, like announcing that a tour is on its way or its part of a live-action skit... which we probably won't be doing much of anymore.
For instance, we have very loud engine noises playing in the FWD engine room, but we are going to remove the equipment in the aft engine room. Tour guides can guide the folks through the noise to give them a feel for what it would have been like and then he'll stop the tour in the aft eng room to explain what is going on and what everything means. The one set of speakers uses a sub-woofer, which actually vibrates the deck plates - pretty cool.
In other rooms, we have random motor and pump noises that add some ambiance to the room, but aren't annoying. We don't play active sonar pings or depth charge noises. The torpedo rooms play recordings of the gyro, speed, and depth changing equipment whirring and clicking and then once in a while there's a loud "whooooosh" for a torpedo launch.
Over the 1MC sometimes we'll play some period music with some added static in the background, but it's not loud enough to drive you crazy after a few hours. Our main goal is to provide some life to the boat, but we don't want to detract from the tour and the actors in each compartment.
