Digeridoos, Monks, Multiphonics, Chaos Theory

[Ken Balys]

I get the same effect by whistling at an anatomically neutral pitch
like say middle C natural and on top of that humming as low a
note as possible in my throat. If someone cannot hear the low
humming you are making, it sounds like you are ring modulating
your own whistle. If they can hear your low frequency throat hum
then they may think that you are utterly insane.

Uh and don't do this if you are on a date and are trying to
impress...

Cheers,
Kenny B.
(Am I analogue?)