Emily Kwong is pretty sure she lacks an inner monologue, while the inner monologue of producer Rachel Carlson won’t stop chatting. But how well can a person know their inner self? And what does science have to say about it? We dig in in this encore episode of Short Wave.To learn more about Charles Fernyhough’s research on voice hearing, visit the project website.  If you liked this episode, check out our episode on when your brain is actually an "adult."Interested in more science inside your brain? Email us your question at shortwave@npr.org.Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.