In many
cases, but not all; if you have the chat minimized, when it is maximized (manually or by auto focus), the little ding you hear when people talk or join is played as many times as their are lines of text in the chat.
So as you can imagine, it can be quite the drum solo if you have been chatting for a while. We have noticed this on the client and admin side of the support chat on more than one computer.