Quote:
Originally Posted by
bigshot 
There have been studies where they rolled off upper frequencies in music and polled listeners to find out 1) if they could tell the frequencies were missing, and 2) if it made a difference to the music. The results were that although listeners could tell if everything above 10kHz was rolled off, but they said it didn't affect sound quality. Above 14kHz, they couldn't tell at all.
The frequency range is not an even scale. It doubles with each octave. So the difference between 20Hz and 40Hz is exactly the same as the difference between 10,000 Hz and 20,000 Hz. When you are talking about the difference between 20kHz and 21.5 kHz, you are talking about a single note's difference on a piano. 15kHz to 20kHz is four notes.
If you are "feeling" a high frequency note by turning up the volume, you aren't necessarily *hearing* that note. Everyone can feel sound pressure from inaudible frequencies if they're loud enough.
The middle of the frequency range is what matters. Don't worry about the stuff only bats can hear.
Seems like what people say if they can't hear to 20 kHz and beyond. Sour grapes. 
Nah, I'm pretty sure part of my top-octave hearing has been absent since I was a kid, since I remember having to go to an audiologist after the test at the pediatrician's office came up unusual. I don't really remember, and it's not like they told me the details. Now I can't hear much past 12 kHz clearly, but I'm not sure if the range is less or the same as it used to be.
Maybe to compensate, I have decent absolute ("perfect") pitch in the range remaining, though...