That's the thing. I don't think we were saying the incantations out loud. It's done left and right in the films, but in the books, only very talented witches and wizards can do silent magic. Of course, Voldemort and Dumbledore would be two of those. What was so unsettling was that Dumbledore was after me! We were exchanging spells left and right from fairly close range.
hahaha that's pretty funny. I wish I could have Harry potter duels in my dreams, if only I could remember the spells.