Science of screaming: acoustics that trigger our fear centre identified

Study on human screaming at New York University reveals how rapid rate of wide unperceived volume changes or 'roughness' elicits emotional response

Human screams have a unique acoustic property that triggers the brain's fear centre more effectively than almost any other sound, scientists have found.

After testing a variety of noises, including human speech and musical instruments, the only other sounds that appeared to activate the brain in a similar way were car alarms and police sirens, the study found - perhaps explaining why they are so unpleasant to listen to and almost impossible to ignore.