So what's stopping people from telling others what to say? I can't see this working.
if it's something absolutely requiring sound, and someone is clearly showing signs of not downloading
A) they'll always be with a disadvantage
B) they'll be oblivious to events that might require sound
C) in-game experience will be bad
D) they'll be kicked/banned by admins until they get the message if it's hindering a game
so really it's their loss if they can't type a simple message