Beetlesmod has this functionality built in by default. About 2/3 of the way down the defaults.cfg file there's a massive block of commented out settings for Quake or UT sounds, whichever you decide to use you can plug into the system.
If you're going to use the sounds, please do us all a favor and don't use the centersay message system with it. Clients can refuse sounds, but they can't disable the giant white text in the middle of the screen that announces things every five seconds. Just a word of advice from a fellow server host.