An exploding head. “That’s why you get these crazy-loud noises that you can’t explain, and they’re not actual noises in your environment,” Brian Sharpless, an author of the study, said in a statement.

Have you ever been drifting off to sleep when suddenly you hear what sounds like a gunshot, a door slamming, or an explosion inside your head? You jolt awake, heart pounding, sit upright in bed, but ...