only thing i gathered from searching so far is:
"The general rules for the use of the devices, which are now used by one player on defense as well, are:
They are shut off, by game-day personnel, with 15 seconds left on the play clock. So with a full 40-second play clock, the coach gets 25 seconds to communicate.
Only one coach can communicate to the quarterback, and that coach has to be on the field, in the bench area. If the offensive coordinator is the team's play-caller and is in the press box, then he relays a play to a designated assistant coach on the field and that assistant coach relays it to the quarterback.
Up to three quarterbacks can have a receiver and speaker in their helmets. There are no microphones.
The same rules apply to the designated defensive player with the device in his helmet, with up to two defensive players allowed to have a device in their helmets. Only one defensive player can wear the device on the field, however; the second device with the second player is used in case of injury."
So they're still screwed imo
http://www.nfl.com/news/story/09000...alls-new-coachtodefense-communications-system
http://usatoday30.usatoday.com/sports/football/nfl/2008-08-27-helmet-radios_N.htm