Years ago I lost the ability to fall asleep in silence. I require consistent background noise in order to drift off. I’m not alone here; many people can’t get to sleep without some kind of ambient sound in the room. My son uses a fan for this purpose. An old girlfriend of mine (number three, for those keeping track) showed me her standby, the sleep timer button. “All hotel TV remotes have a sleep timer button,” she informed me one night. “How do you not know that?” She could get mouthy. I don’t use a fan or television to fall asleep. I use podcasts on my iPhone. And here are my five favorite podcasts for that purpose.