For years at UNH, we've put a card and a golf pencil at each graduate's seat, they are instructed to write the phonetic pronunciation of their name on the card before the go up, and they hand it to the name reader on the stage. It's worked at least well enough that we've never had anyone get booed. We also keep the name reader at a mic right where the people come up on the stage so that if they aren't sure what the card says, they can ask the student quietly off mic.
That said, I totally agree with Mic's recommendation of using a professional voiceover artist - we've used Bill Rogers for a bunch of stuff, including some with very difficult chinese names. We were on a phone call with him while he recorded, so we could have a native speaker give him the correct pronunciations and he did great with them. (If you end up talking to him -
bi...@billrogers.la - tell him that Andy from UNH sent you - he's a great guy, and has very reasonable rates.)