Having gone to Bruce's cube to talk to him on several occasions, I can confirm that his headphones cancel noises (such as people saying his name or knocking on his cube wall to get his attention) quite well.
Eh, maybe he just doesn't want to talk to you (or, not picking on you, but maybe he doesn't want to talk to anyone)? Try standing near him and talking smack about his latest creation, then see how much noise is really canceled...
