You’ve probably never heard of Robin Miles, but you may well have heard her—possibly at some length. Miles is an actor who’s cultivated a particular specialty in recording audiobooks, a booming segment of the publishing industry. She has lent her voice to more than 400 titles in all sorts of genres—from the classic “Charlotte’s Web” to Isabel Wilkerson’s “Caste,” a deep analysis of race in America. “Telling a story, fully, all of it—from all the aspects of it—and creating the kind of intimacy between you and your listener is so satisfying,” she tells the New Yorker editor Daniel Gross. “Being in a great play means you have to have the money and the other actors and a script and a director. This is just me and my book, and I love that.”