When you get your first sound locomotive its cool, Crank the sound up to maximum and away you go. Once loco number 2 arrives, it does get rather noisy. I have the maximum sound on my locomotives set at between 25-30%, loud enough to hear but not be annoying in your layout room.
Move on to the exhibition circuit and you don't need sound in HO layouts, you cant hear it even at 100% maximum sound. But move into Gauge one and it is cool. You can hear it and surprisingly it is not over powering. A true great atmosphere.
John