Although this idea is respectable I think that we should leave that to the mind of the player and not the programming. It is far more interesting to see how 'real' psychology works in DayZ as opposed to artificial meters.

Scared the shit out of me when my friend was axing a zombie and he had hit the wooden fence next to him and it not only made a gunshot sound but, looked as if it had made a bullet hole in the fence as well.