(DAILYMAIL) — If you've ever heard a 'boom' in the night that you can't explain, you might have 'exploding head syndrome', psychologists warn.
It's estimated between 10 and 20 per cent of people have experienced this bizarre condition, in which a person is woken up by an abrupt loud noise they soon realise is imaginary, a study found.
The phenomenon strikes as a person is dropping off to sleep.
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And the type of noise can vary from explosions and fireworks to slammed doors, the sound of a gun firing, an enormous roar, shouting, thunder or a crack of lightning.