Why are screams terrifying?

You know a scream when you hear it. Whether a shriek, a howl, or a holler, when that familiar sound reaches your ears, you know something’s wrong. Screams can even be distinctive, so much so that films use particularly “good” screams over and over again. But what’s in a scream, really? Why do we find them so innately alarming?

According to new research from scientists at New York University, screams occupy a unique place in the audio spectrum when it comes to normal conversation and it has to do with a quality of sound called “roughness”.

That unique characteristic is why we freak out when someone yells “OH MY GOD” in pain, and not when loudly and sarcastically remarking about what the hell Joe is wearing today.

“In terms of vocal communication, it seems like screams are actually unique,” said Luc Arnal, one of the researchers who led the study, and who is now based at the University of Geneva. “You want alarm sounds to be unique and not share frequencies with other signals to trigger false alarms. If you have scream-like frequencies in speech, then people would be afraid all the time.”