(non-pilot speaking) Yesterday I has a most interesting example of the way in which human audio processing is inhibited during times of sudden crisis.
In the car approaching a complicated, but to me well known, traffic intersection. I was listening to a spoken word radio programme and was following the conversation. As I moved into the junction, a car on my left made an erratic movement and threatened to enter the road space that I was driving into. At the same moment, I saw a Police car parked on the far side with it's blue lights on and I had to assess what the problem was and how it would affect me, as well as avoiding being hit by the car on my left.
Fortunately, all went well and I exited from the junction without incident. This was not a crisis, just a momentary every day traffic problem but, as I drove away, I realised that I had 'lost' about 7 seconds of the radio programme as my brain focused on the problem.
Professional pilots are, of course, trained rigorously to be able to maintain sensory input but it was a fascinating example of how easily the hearing function is 'downgraded' by the brain. Which led me to think that enhanced audio prompting as suggested in this thread, "Retard Two, Retard Two" may not have the desired effect. Of course, that is no reason not to implement it as we cannot know how we are going to react when faced with 'the real thing'.