If the even subtle ping produced by playing the vinyl-undercoated, metal-alloy Surge cymbals is still too loud for you, the new Alesis DM10 Studio Kit is what you're looking for. The Studio Kit's fully rubberized triggers and muffled real-feel drum heads are just about the stealthiest on any electronic drum kit.
We shot the DM10 Studio in action at Winter NAMM 2010, and it's a good thing we took a direct feed from the DM10 module -- otherwise you wouldn't hear the thing at all. Speaking of which. . . if we took a direct signal, what is Jason Donnelly dancing to?