Calley-ope (calliope) Syndrome is pronouncing a word wrong because you’ve only ever read it on the page
This is a phrase that goes around the Internet every once in a while, but there’s no definitive reference page for it.
Where does it come from?
Several sources on the Internet point to Judith Wynn Halsted’s book Some of My Best Friends Are Books: Guiding Gifted Readers. The Internet Archive has digitised the second edition from 2002, and the relevant passage is on page 207:
Books that contain pronunciation guides are helpful for gifted readers (though they are rare, and a pleasant surprise when found), since so many avid readers know words only from reading and therefore mispronounce them. One excellent teacher of gifted high school students calls this “The Calley-ope (calliope) Syndrome.”
An almost-identical passage appears in one of her earlier books, Guiding Gifted Readers, published in 1988. (The two books have a very similar structure, so I think this is a “first edition” of Some of My Best Friends – but of course, not described that way at time of publication.) It’s been digitised by the Internet Archive and the passage is on page 126:
Pronunciation guides are helpful for gifted readers (though they are rare, and a pleasant surprise when found), since so many of them know words only from reading and therefore mispronounce them. One excellent teacher of gifted high school students calls this “The Calley-ope (calliope) Syndrome.”
But this doesn’t tell me which teacher coined the phrase!