[Gerard]

I'm 47, and can just hear 15KHz. 14KHz is painful. I've always been overly sensitive to the higher frequencies, not in the sense of hearing way up high, but rather experiencing physical pain when I hear anything over about 10KHz. Must be part of why I gravitated towards working with bass instruments and play the cello myself.

On a note about listening to these tones on a computer; I found nothing was audible above 12KHz at first, but then remembered that my RealTek Audio setup was such that most volume above 10KHz was scrubbed. As I said, those frequencies and me do not get along. So I temporarily disabled the mixer and re-tested, and found that a) the range I could hear went a lot higher, and b) that the background hum/hiss in the test tones vanished and a clear tone was audible. If anyone's having trouble hearing these tones, and especially if you hear ANY background noise besides a clear sine signal, disable your EQ and try again.

I'd guess that speaker quality might play a large role in hearing some of the higher frequencies. I listened through the speakers of my Asus 901 netbook first, and found it somewhat more difficult to hear the upper levels of my range. Listening again with BeyerDynamic DT 880 headphones was a lot more focused in all frequencies.