For out-of-universe English speakers, what would be the correct pronunciation of "Accio"?
Has J.K. Rowling ever been heard to say it or commented on the correct phonetic pronunciation?
The question arises because at least three, possibly authoritative sources indicate three different pronunciations.
1) Stephen Fry — Narrator UK (audio book): ax-see-o
2) Jim Dale — Narrator US (audio book): ass-see-o
3) Films — (example: Harry in Goblet of Fire): ack-e-o