Headset on/off notifications?

We are developing a multi-player game and want to have a player enter/leave the room when the headset is put on (awake) or taken off (sleep). Is there a hook/event for this? We are using the GearVR headset by Samsung.

Ok, I found the solution:

public void OnApplicationPause (bool paused)

Pause is called about 10 seconds after the headset is removed.
Resume (paused == false) is called immediately when headset is put back on.