(fwd) Re: "ghost flute" article

I am forwarding this interesting article from sci.physics, Ray.
dgoncz@aol.com (DGoncz) wrote:

>My physics teacher told me about an article in a physics journal from back in
>the 60's or 70's about a pehnomenon called the "ghost flute".

Probably Scientific American. I don't think a physics journal would
publish a paper on perception of a beat note.

Let's say we have a flute at A440. And another at (perfect) E1320. The
beat will be at A880, which does happen to be in the range. A beat can
be either in or out of the range of the instruments creating it. In the
range, it sounds corporeal. Outside the range, it sounds ethereal. I am
stretching, but I think this is clear.

That beat would be hidden by the second harmonic of the lower flute.
(Even though flutes tend not to have second harmonics, the ear can fill
it in.) A more striking demonstration might be the A 440 and the perfect
D 1010. The beat would be 570, anharmonic to A, within range, and might
sound pretty out of place. I am guessing it's about a minor third.

Yours, Doug Goncz
Replikon Research, PO Box 4094, Seven Corners, VA 22044-0094
http://users.aol.com/DGoncz