I don't know if such thing is possible (probably it will, but just not right there yet?).
Maybe there could be created a script that triggers a sound by using the cn (like as example "you are tied for the lead" when you and an opponent are having the same score and are first)
I was thinking (probably I shouldn't but oh well...) that a script continuesly checks the cn numbers and frags of each client. If any clients have the same score and both the highest score (wich maybe could be tricky that the script continuesly checks wich cn is has the highest score), sound "you are tied for the lead" get's played.
Good idea? bad idea :P?
Unfortunatly I won't be able to make such script, since I don't get cubescript :S...