!ring - Ring the room generally with a bell sound. The sound is quiet and is there to indicate activity.
!buzz player - Make a louder sound to grab the attention of a specific player. Max 2 per minute. Player can choose the sound or disable it in lobby options.
!checkdl - Check how long until everyone's downloads finish. No sound.
Different sounds for different purposes, so I don't have to look at text to check if someone specifically needs me or its just another map vote.
The default for the buzz sound should of course be a random Duke quote.