Frequency Range of Hearing (question)

[A.J. Aranyosi]

Michael B. Tinsley (mbtins01 at starbase.spd.louisville.edu) wrote:
: The last tone that
: we generated was a 15.9kHz tone.  I didn't hear a thing and I thought
: that the program was not working.  However, my lab partners heard it as
: soon as I executed the program.
: My question is this....is this something that I should be concerned
: about?  I know that most people can hear from 20-20kHz.  My cutoff
: appears to be 16kHz.  I am still young and I haven't had any health
: problems.  So...what gives?

The 20-20kHz story is, frankly, a lie.  You would be very hard-pressed to
find someone who can actually hear a 20 kHz tone at any reasonable sound
level.  If you look at psychophysical measurements of hearing (check out
the ANSI standards sometime), you'll see that the average threshold of
hearing at 20 Hz is somewhere around 60 dB SPL, and the same is true for
frequencies near 20 kHz.  In other words, most people aren't going to hear 
tones at those frequencies at reasonable sound levels.  Since you didn't
tell us what the sound pressure levels you were using were, it's hard to
know whether your situation is normal or not.

Of course, the other lie has to do with the importance of hearing at these
frequencies.  Speech (which is, frankly, what we use our hearing for most
of the time) contains useful information up to about 4 kHz.  The highest
note on a piano is also about 4 kHz.  Admittedly you might want to hear
the harmonics of a piano, but even so, once you get to the 4th harmonic
at 16 kHz you're not likely to hear much.  So as long as your hearing is
normal below 4-8 kHz, you have nothing to worry about

-- 
A.J. Aranyosi                 Speech and Hearing Sciences Graduate Student
aja at mit.edu     Heard on the news:  "Two trains were involved in a head-on
collision in Virginia.  Investigators suspect one was on the wrong track."
         Home page:  http://www.mit.edu:8001/people/aja/home.html