It can be hard enough to answer the question, "what kind of music do you like?" But how about "why do you like it?" That's one of the many questions about the human brain and sound that neuroscientist Nina Kraus set out to answer in her book Of Sound Mind. In this interview with NPR's Ari Shapiro, she breaks down the science behind what our brains do when they process sound, and how it differs for each of us.