Headphone Usage

[grantsrc]

I thought that this might fit in the other post but thought I would start its own thread.

Last year we had a situation where the coach would come onto the field during a time out wearing his head phones. Federation Rules apply here. Now I know there are rules about players wearing headphones during the game as addressed in the other thread, but what about the coach? I don't have my rule books handy but, does it matter if the conference is held on field or by the sidelines? Or does it even matter? Can a coach wear the headphones during a charged timeout no matter where the meeting occurs? Should this even be addressed?

Thanks for your help.