Players of the old school remember using RadioMod on TFC or CS 1.6 in an “AdminOP-esque” server set up. It’s a lot more convenient in Sven Co-op, actually. All you have to do is install the Angelscript plugin. Download it here.
For those of you who are not familiar, what happens is that when you say a “linked” word in text, anything like “lol” or “hello”, a sound file associated with that word will play. It’s a pretty silly plug-in but people on fun and minigame servers seem to like it.