Sound-Powered Telephone System

With the firefighting though wouldn't the AI be in charge of that? I think what happens is we just assume the AI is going to take care of such measures since they fall along the lines of the ship's self-preservation parameters. Although if the system was down and it was left to be fought manually there could be special fire extinguisher units with a pressure charged chemical that would be used to fight the fire like modern day fire extinguishers. Maybe just make the units capable of carrying a lot more extinguishant then today's since they only have enough to maintain a constant spray for a few minutes. A serious fire would require a much more long lasting system. Also you got to take into consideration the hazard of the fumes, the material burning, the chemical required to extinguish the fire, etc. It all gets pretty scientific since you don't want to kill the person fighting the fire with the fire extinguisher itself.

Perhaps a hose system that is linked to the ship. Instead of the smaller portable units you could have hoses like those wall mounted ones in facilities that draw water from the water system. Except I guess these would draw something... else? Replicated extinguishing chemicals?

I'll be upgrading the SA ships to include fire protection. Since the AI requires power, we can't always rely on it in combat. Every Star Army soldier should know how to fight ship-board fires (much like how in the US Navy, every sailor does).