Sorry about the title, it’s the best I could come up with… 
Anyways, someone in my class recently told of an experiment many years ago where they isolated a child from any speech or sounds and he eventually began speaking a known language (that is from somewhere near the Amazon or a language that a tribe speaks)… It seems outlandish to me, but he swears it to be true. Has anyone here heard of anything like that?
I seriously hope that no modern person (pretender to science or otherwise foolish) has actually done anything so cruel.
I suspect that most such stories are re-hashed versions of this tale from earlier times. Herodotus reported that the Egyptian Pharoah Psammetichus, ca. 650 B.C.E., ordered two children to be isolated and their first word recorded. That word was bekos which happened to be the Phrygian word for bread. Phrygian was a little-spoken language from a location remote from Egypt (and has since died out as a language), so it seems to support the notion of “a primitive language from far away” that such stories tend to embrace.
There are two other stories:
HRE emperor Frederick II is supposed to have tried it, but the children died. (This story sounds plausible given that children treated to cold silence would quite possibly fail to thrive.)
James IV of Scotland is supposed to have tried it, with the improbable result that the children broke into fluent Hebrew.
According to a book I read the two children were cared for by a shepard that was instructed to feed them but never talk to them. Some have speculated that when the child said bekos he was actually just saying Bahhh becuase he had overheard the sheep outside that the shepard also cared for.