Have to agree with John Citizen-sitting in the cruise far less chance of missing a radio call if reading rather than talking. Training flights a classic example of this as -in our company at least- there are far more radio calls missed during training flights than normal line ops. Try doing nothing for a 10 hr BoC 2 pilot sector, primarily over the non-English speaking world-and then tell me what that does to your SA in an already fatigued state. Same school of thought that says at night the cockpit lights should be dim-despite all fatigue research recommending brightness reduces fatigue. 30 mins required for dark adaptation-which is not really necessary when flying to an airport equipped with Approach Lights, and we don't normally worry about the night fighters homing in on the glow from the cockpit these days....