How would this work then.
If he is breaking the sound barrier and was going 'aaaaaaaaaaarrrrrggghhhhhh' all the way down (thats what i would be doing anyway) would he not hear himself until he landed then???
:-) Good luck Steve.
p.s. How is the sponsorship going Sam for your run, i sponsored you here
Sam Still - World Champion 2005 (Static Apnea)