I think you're referring to this: http://en.wikipedia.org/wiki/Missing_fundamental http://en.wikipedia.org/wiki/Missing_fundamental Which, since it's a psychoa

I think you're referring to this: http://en.wikipedia.org/wiki/Missing_fundamental http://en.wikipedia.org/wiki/Missing_fundamental Which, since it's a psychoacoustic phenomenon, wouldn't hold true when the partials involved are above the audible spectrum.