audible resultant from two supersonic frequencies?

[Richard Moody]

----- Original Message -----
From: Clyde Hollinger <cedel@supernet.com>
To: Pianotech <pianotech@ptg.org>
Sent: Monday, December 02, 2002 6:06 AM
Subject: Re: audible resultant from two supersonic frequencies?


> Ric,
>
> I am confused by your question.  First, do you really mean
>supersonic,  defined as greater than the speed of sound waves?  I
>think you may mean ultrasound, defined as sound with a frequency
>greater than 20,000 Hz, which is approximately the upper limit of
>human hearing.

Clyde,
    You had me doubting for a second, thanks for the point out.
    I am using the definition as given by Webster's 3rd New
International. "Supersonic 1: having a frequency above the
audibility range of the human ear or greaterh than about 20,000
cycles per second --- used of waves and vibrations; compare
infrasonic, sonic. "
    Yes "supersonic flight" is definition number two.  And yes
then I mean "ultrasound" since I see it is defined as. ":a wave
phenomenon of the same physical nature as sound but with
frequencies above the range of human hearing--- also called
supersound".    There is also "ultrasonics" ":the science of
ultrasonic phenomena : supersonic "


>What
> would be the point of experimenting with sounds we can't hear?

The question is,  are there AUDIBLE resultants, which is a sound
we CAN HEAR, that is produced from two frequencies we can't hear
such as 20,440 - 20,000 hz which gives on paper 440 hz  or A440
which certainly we can hear.   An experiment has to be conducted
to determine if this is true.   I am wondering if this has ever
been done, and if not how might it be done?   I need two audio
frequency generators?   Can the computer give hz over 20,000?
How bout tune lab? Would I need two?     ---rm   (the "r" stands
for 'ric' and the "m" stands for "M")