Exploding head syndrome
Exploding head syndrome (EHS), alternately termed episodic cranial sensory shock, is a benign condition in which a person experiences unreal noises that are loud and short, like a bomb exploding or a gunshot, when falling asleep or waking up. These noises are often jarring and frightening for the person. Neither the cause nor the mechanism is known. Though harmless in and of themselves, episodes have been known to create distress or impairment in the lives of individuals.