 I've seen it in elderly people. I've seen it in relatives, where they'll be quite quiet, and all of a sudden they're very, very loud. And then they're very, very quiet. I've also seen the anger. Like, where did that come from? Where you might be in a restaurant, and suddenly they're angry at the waiter. Like, Uncle Bill, what's going on? Well, that's an effect of Parkinson's.