Hand signals are used to combat crowd noise but that's not in the game. Although I agree the crowd noise(aka stadium pulse) give the game a more real world appeal...
There has NEVER been a qb that could not look and see a receiver and throw the ball to them simply due to crowd noise!! The ? mark icon on receivers, the delay in the ability to throw the ball is just not what should be on the game.
Stadium Pulse has and continues to be overpowered in this game(even after recent updates).
The only people that like this feature tend to be Sim players or something who use a top Stadium Pulse team like LSU, Penn State etc.