The ferret sound discrimination idea is very interesting. Unlike R D,
however, I doubt very much that ferrets are communicating using
subsonic frequencies. This is just a guess but it is based on sound
(no pun intended... by that I mean real) physics.

The problem with low frequencies is that it usually takes large
physical structures to create them. Some whales, for example, generate
subsonics that can travel as much as 100 miles (in water). And that is
why the woofers in your speaker system tend to be larger than the
tweeters.

I'm not saying it's impossible that ferrets voice subsonics; only that
it is unlikely.

On the other hand, if ferrets create high-frequency sounds, it is
unlikely that they are outrageously high frequencies, for the same
reason that whales use those very low frequencies: higher frequencies
do not travel as far. The higher the frequency, the faster it fades
with distance. This is why bats use frequencies that are generally
just a little above human hearing. It is easy for their little bodies
to generate, but it is still low enough that it will carry a short
distance.

It should be pretty easy to find out if ferrets actually do this. If
anyone has access to recording equipment that is sensitive to high
frequencies, just record some ferrets for a while. Getting hold of the
recording equipment would probably be the hard part. Then upload the
recording(s) to a computer, and slow them down. That part is not hard
to do: Audacity is one of many programs that will do it, and it's free
software that you can download for Windows, OS X, or Linux.

Lonny Eachus

[Posted in FML 7669]