Truly new sensory experiences are rare. Perhaps for that reason, a whole genre of YouTube videos is dedicated to them. The videos of babies tasting lemons are merely heartwarming. Others—the ones showing deaf people activating their cochlear implants, for example, or blind people, after surgery, seeing for the first time—have a power that’s hard to overstate. (A video of Sarah Churman, a young woman from Texas, hearing her own voice has been viewed more than twenty-five million times.) That power flows from a number of sources. The videos are often filmed by family members who are themselves deeply moved. They involve us in a private, intimate, and life-changing moment. They are unusually frank documents of emotion: one doesn’t often see such extremes of surprise, fear, and joy flow so undisguised across an adult face. And, at the same time, they tell part of a larger, communal story about science and its possibilities. (Perhaps this is why patients and their families are so willing to share these otherwise private moments with the rest of us.)
