1st I don't know.
2nd depends (hugely) how old the person is, mainly, but a reasonable range for a 8 year old child (-6db points) is 20Hz-20kHz, for an old boy it might be 30Hz-12kHz with a bunch of dips in between depending how hard he was clubbing in his mis-spent youth. 20,000hr ATPs are usually deaf as wooden posts, perhaps 30Hz-6kHz and most won't pass the JAA initial audiogram
