Doing the Greek course on Duolingo, I discovered that several of the pronunciations for Greek letters I learned in college are incorrect. In gross terms (I don'

Doing the Greek course on Duolingo, I discovered that several of the pronunciations for Greek letters I learned in college are incorrect. In gross terms (I don't really know how to use IPA to be more specific here): beta -> veta, delta -> thelta, for example.