One piece of obvious advice for any British-born actor who books a voice over job in the U.S.: make sure you read the copy several times, particularly any key words that you think you can pronounce. I thought “medieval” was pronounced the English way, as it is written: medi-evil. Of course, the American pronunciation is a tad different:
and it’s delivered quicker.
I remember feeling a bit thrown when I heard the director say, “It’s not medi-evil; it’s mid-eval.”
It was tough at first to remember the American pronunciation. Thankfully, it passed!