We have this option enabled:
"Enable live chat notification sounds - Checking this box will enable SmarterTrack to play a sound when a chat message is received. By default, this option is enabled."
However agents are not notified with a sound when the customer has written a new message in the live chat.
We're currently on SmarterTrack 10.5 and will be doing the minor upgrade shortly but I don't believe this is something that is listed in the bug fixes so assuming it will still be an issue after upgrading as well.
There are other issues which I'll post separately about (agents not even enabled for live chat in a specific group still hearing queue and idle warnings)