Hi Alison,
Please forgive my ignorance, but I've looked up hyperlexia and still really don't understand it.  Do misspelled words interfere with a hyperlexic's ability to process the words?  Or are they just a nuisance?  Or something else entirely?  I have to admit that years ago I couldn't finish the book "I know why the caged bird sings"  because there was so much "African-American Vernacular English" that I simply couldn't comprehend it.  Perhaps if I had read it out loud to hear the words  I would have understood it better? (Which is a strategy I just now thought of).  
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I had "mis-remembered" the book title as "I've heard the caged bird sing" which is funny because, as I just mentioned, had I heard it read aloud maybe I would have "heard" (understood) the book. Ya heard?   (http://www.urbandictionary.com/define.ph...ya%20heard)  
Thanks for indulging my word-play.
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Anyway...
Thanks in advanced for any insight you have on this,
Lydia