Well, it does work in that it stops the radio messages from appearing on screen, if you issue an order to a team member to, for example, board a vehicle, the order you issue is still heard, but any reply from the team member, for example "Roger" will not be heard.
However it is less than perfect as some messages still get through, like when a team member has moved to a location he was sent to, you will hear him say "Ready".
Planck