Cheers!

• http://www.dogstar.dantimax.dk/acoustic/index.htm

I think I've read that before because I remember the concept of psycho-acoustic summming and virtual FMD or some such thing. Seems like a frequency was perceived like a beat frequency in some cases, even if there was no non-linearity present to acount for it. Very low frequency perception could be generated where no LF content was present, and FMD gargling was perceived when none was present in the source. Thanks for the link, I'll look through it.

Wayne