Exploding head syndrome is a term used to describe a sleep disorder that causes a person to hear loud, sudden noises in their head as they fall asleep or wake up. Although there is no known cure for this condition, there are some synonyms that can be used to describe it. Some of these include "auditory hallucinations," "sleep-related auditory hallucinations," "hypnagogic auditory hallucinations," and "sleep start auditory hallucinations." While these terms may differ slightly in definition, they all refer to the same condition and can be used interchangeably to describe the experience of hearing loud, sudden noises in the head during sleep.