Ah! That's the point. Knowing how the ear is
seen relative to other parts of the
head is not the same thing as pointing one's finger to
what I hear with on one's own
head! As far as that goes, both the reconstruction of what made the ear drum vibrate as speech, as rustles in the grass, as Mozart (or your
choice), and that which the retina gathers and sends via the optic never "are" speech/music or images/form but require developed neuronal networks in the brain to become visual or aural means of communication and thought. And the development of all these neuronal networks (and others, of course) is post partem and indeed takes quite a lot of further brain growth, too. There are
good, plain reasons why your 12-year-old students are, 99% of them, not ready for serious algebra and, it has been pointed out, they don't have the kind of judgment needed for driving on freeways or making adequately considered decisions about their own lives. It isn't exactly
poor judgment but their having
brains as immature as their bones and muscles. And, of course, you mustn't let them play football the way that the NFL play it (I won't discuss the latter, but you can imagine from my reverence for the human brain what I think of great risk of injuring it).
Those are horribly long sentences, and I apologize. PS: just think of the CCD in your digital camera, and that's simple compared with your brain.
Pat