------ Dennis wrote:
>> I need to do some reasearch on if there is
> a portion of the human population. i.e.
> .002 percent which can hear frequencies
> above and below normal hearing.
>> Unfortunately I have no suitable equipment
> to use. Any suggestions?
>>w6089 at cloudnet.com
Are you assuming there is something magic about 20 Hz and 20000 Hz such
that no one would hear 19.9 Hz or 20,001 Hz? I know I have heard a tone
at 19.75 Hz. I expect many can hear a strong enough sound a little
below 20 Hz, and many young people especially probably hear some sound
above 20,000 Hz if it is loud enough. You really have to consider
actual frequency and strength of the signal as well as the human