Why is it everyone always tiptoes around these annoying pricks?! Just go up to him and tell him he's bothering EVERYONE ELSE and that he needs to either turn it down or face consequences. Jeez.
If you really wanted to be vindictive you simply add a new admin account, don't give him the password to it, and then downgrade his user account to restricted user. Then you can limit which apps he can use, including iTunes, Windows Media Player -- anything that can play sounds, news, music, fart noises...whatever.
Though Felonious is on the right track here.
