[Re: Time to kill the 20KHz myth.]

[Karl Helmer Torvmark]

On 29 May 1999, Harry Bissell wrote:

> Tony:
> Depending on whether that was a newer or older unit, you might be surprised
> how that 40 KHz was produced. An old RCA "Space Command" sending unit had
> spring loaded "hammers" which struck resonant steel bars. Hold THAT to your
> ear and you WILL hear it. If the 40KHz is loud enough, non-linear ear response
> could allow you to feel the pressure.

Yes, I've heard that story too. It seems that you can hear up to 40kHz
when the sound travels by bone conduction in your skull.
 
> I don't agree about the 18-19K. As a child, I told my father (working on a
> phono preamp) that I could hear the sine wave oscillator. He said (lovingly)
> "BULLSHIT KID... Nobody can hear that high." Mamma said "If my kid says he can
> hear it, he can hear it..." Papa said "OK, Turn around, kid..." and started to
> sweep down from 30KHz. I could tell him when he got to 22KHz every time,
> without looking.
> 
> Alas, a couple of years ago (at 40) I repeated the test. Try as I might, I can
> only hear up to 18KHz now, and only if I try really hard.
> 
> Youth is wasted on the young....  :-) Harry

The funny thing is that the most fanatic audiophiles I've come across are
middle aged. They might have heard 20kHz in their youth, but....

I'm 23, and I think my limit is around 19kHz.

One of the interesting things about hearing is that it differs so much
from individual to individual. The shape of the external ear varies, the
length of the ear canal varies from person to person.

---------
Karl H.