Well, I did the test that someone suggested on this list: I set up a little PD patch to
generate sine waves, and swept it up and down to determine the range of my hearing.
I was pleasantly (well sort of) surprised.
At very nearly age 44, the highest sound I can hear as an actual sound, when turned up
really loud, is 18100Hz. Up to about 19Khz, I can get a really freakin huge headache from
sounds, but won't be able to perceive them as sounds, just as
OH-MY-GOD-MY-HEAD-HURTS-MAKE-IT-STOP!
At normal listening levels, around 16kHz is the maximum I can hear.
Still a good deal better than I expected.
-ken