My first roguelike I've added sound to is Left Field Hotel. My older roguelikes did not have any sound, and honestly, audio is a big deal. You don't need to overload your game with sound effects, but even a small amount can add another dimension to the game, which is good.
In Left Field Hotel, the sounds mainly include opening things, clicking, banging, completing an objective and other miscellaneous things. Almost all of the time, there will be some background ambience, whether it be wind, or sound cues telling you there is an enemy near by. Many actions create no sound whatsoever, however. You sort of need to decide what is worth having a sound for, and what isn't.
I'm not saying that all games need to have sound, especially roguelikes. Heh, most roguelikes barely have any graphics.