Hi Sandra! Good to reconnect with you too! Yeah, using your voice is one of the main secrets of the book. Birds actually enjoy our voices the way we enjoy theirs (high-pitched voices, like women's or children's, or a man talking falsetto). When we are outside having conversations, birds may perch around us listening to us. And, like your owl, they can answer us back if we answer their calls. Of course, sometimes they may ignore us, because calls like owl hoots are mainly a way for mates to locate each other and the owl may be thinking more about that. But sometimes they may stop and talk to us anyway. Flickers, same thing, here's a vid I caught of a flicker answering me back when I answered its call. This call is also used between mates or between parents and youngsters to locate each other, so flickers will often ignore me when I answer them because they have other things on their mind, but sometimes they reply, and even if they ignore me in the moment, over time the flickers get friendlier when I regularly answer their calls.
Love and Blue Light,
Gayle