Got my attention with those questions. Not even wondering if you know the answers. They generated other questions - see below. And, I've stifled the desire to run to some possible ready answer tomes. Because of my musical nature, I'm going to approach this from the empirical side first.

I did a quick little test of my own. I can recognize a chord (Cmajor in this case, also tested minors and 9/6ths and augmented and diminished) if it is sounded for 100th sec. I have no apparatus to take it down to smaller degrees tonight.

I'm also wondering about bone conduction which allows one of my deaf friends to discern major and minor chords with incredible accuracy (he used to be able to hear, I admit, but he's totally deaf now). Haven't tested him for duration though.

I'll rev up my recording gear and try some samples at various rates for further empirical testing results tomorrow afternoon.

I need some baseline on my hearing, which I'm sure is quite different from a thirteen year old's. In other words, I can only respond for myself. I think only inferences can be made at that point, but individual tests can then be made and duplicated (or not) by anyone willing to follow my experiment even though the answer they arrive at is going to be different for each person and only a PHYSICAL answer at that.

As for the answer to the question, I suspect there's an eloquent outcome from this, and I state for the record (this isn't the answer yet folks):

Regardless of the duration of Nonrecognition, the resultant will be (assuming one or more than one instance as in a "piece" of music combined and "played back") in the realm of subauditory expression or at the most recognizable only in the sense of say, a twelve tone row a la Webern and his ilk, played at threshold level, one note (tone, wave form) at a time.

A music teacher would say it isn't a chord if I don't recognize it as such. And there are teachers out there that maintain a chord is simply an implied structure measured by the listeners ability to erect it. There are many "two note" (power) chordists out there in the pop field today. Webern would demand his works not even imply a chord - mighty hard to do if you are following any kind of music theory.

A physicist would say it isn't a chord if the wave forms are not present to maintain the (harmonic) structure and frequency order (right , Bruce? - If not tell me now and I'll complain to Dr. Mills promptly).

Sub to the above, could it be that failing the chord, the individual failed chords could be sounded together to make a "full" chord? Would a musician "build" a chord out of a non-chord row or individual non-chord? A non musician? A deaf person?

Notes: On the true auditory level: Will subjective responses to testing result in misconceptions? Is it possible to entirely rule out subjectivity? The pure physical laws may not apply - brain noise (imagined noise)?

I may be wrong, but it "feels" like that.

And for you others reading this, I did say Old Fashioned Way first. I'll see what pure physics holds later. I want to see about an assemblege of failed chords in practice. Gawd, SPL's, constant wave forms analysis, harmonic theory, atmospherics, EDL's - sheesh! (cackling)(ROTFLMAO)!

I contend that for practical purposes it doesn't matter to me as a musician unless it can be prepared and "played." If it indeed can be "played" it may have some interesting uses in regard to listener trends. The concept bears inspection anyway - what a neat thought you had Bruce. Removing myself far enough away from the question to be scientific about it ain't easy.

I'm very curious about the result. I'll try my best to use no handy references. As I stated, this is an OFW experiment. I feel that just looking at the problem will bring out the Heisenberg in ME. *BG*

For your question, you asked for subtle, so:

In the newly theorized mirror order universe, are you playing a CEG chord to your opposites A#AD? What does he hear it as? What would he hear your chord structure as? Are you louder or softer? (Whoops - more than one question - or is it?)

Last but not least, I think evolutionary ears is a distinct possibility. It would rankle me a bit to think Lucy had yours or mine (but I'd get over it).