For the past several months, I’ve fallen asleep listening to a woman named Teri—or someone like her—every night. I crawl into bed around midnight, open a certain proprietary wellness app on my phone, tap the “sleep hypnosis” section, and mindlessly select one of the hundreds of available tracks. Then I place my phone face-down on my pillow, just beside my head, and focus on the voice in my ear. I often drift off before the recording is over. I haven’t slept so well in years.