Exploding head syndrome (EHS) is a real sleep disorder says Washington State University research Brain Sharpless. The syndrome is recognized in the International Classification of Sleep Disorders, but it is largely mysterious. The term was first used in a Lancet article in 1988. It is more common in women than men. Sharpless, a WSU assistant professor and director of the university psychology clinic, says people with the syndrome perceive abrupt, loud noises as they are going to sleep or waking up. These noises may sound like door slams, fireworks or even gunshots.