How did the Betazoid language develop, have they always been telepathic and if so how would have effected their communication. Why speak aloud at all? What gets written down? Does communication telepathically and verbally differ, is their a grammar and syntax, etc...?
For that matter how does telepathy work if we all think in our native languages?
Do they even have a written language, I ask because if I remember correctly the Efrosians use sound to record their history and knowledge, what with having poor eyesight.