Audio notification when someone enters waiting room?

Separate from notification when someone enters or leaves room, no. But that will do it.
There used to be an issue that once the audio notification was turned on, it would (usually) not turn off. I think that has been resolved.

I have been researching this for 2 full days now.  It absolutely must not exist.  So I have to STARE at my screen nonstop until everyone is in.  Seems like an easy thing to create...