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You bring up an interesting point. The pitches probably couldn't match between adults since men's voices would be lower. But, oh, suppose they matched on the octaves! Now that would be something to consider! But I doubt it.
All I know--and it is very little--is when I tried to duplicate the inflected tones of individual words in Vietnamese, I had my students in stitches. The inflection is by far more restricted that just an inflection to show a question with our voices, although it would be related in a very general sense, of troy. The inflected tones were so small in terms of audible range, that I could not hear them correctly and then reproduce them correctly to my students often. Sometimes--strictly by chance and a fairly good western ear--I would nail the sucker. And my students would applaud. But I learned that it would be a cold day in hell before I'd try in earnest to learn Vietnamese. I had trouble enough with trying to speak French to a French man once--I thoroughly annoyed him.
If we had a tape available--a sound file--so that the AWADers could hear these Vietnamese inflections and how very slight differences in inflection change word meaning, that would be helpful, particularly for a general sound differently inflected that would mean about four or five different words.
My question is: Do highly trained speakers with very musical voices use the right brain at all? I would guess they must. And if they do, then the rest of us might a little, if not to the degree of highly inflected languages, such as Mandarin, from what the opening post suggests.