Why are screams so frightening? Because sounds with frequency modulations in 30-150 Hz range have a particular "roughness" to them that activates the fear circuit in the amygdala, according to research published in Current Biology, titled "Human Screams Occupy a Privileged Niche in the Communication Soundscape."
That's not a vey satisfying answer, but the interesting thing is how consumer electronics companies, law enforcement, and collection agencies can use synthesized screams to encourage people to do things they'd rather not do.
Motherboard reports:
The more rough a sound was, the more freaked out the patients reported themselves as feeling. According to Arnal, this information could be used to make alarms more, well, alarming.
"If you take a basic pure tone and modulate it in the roughness range, it's going to sound alarming," Arnal said. "That's a way to improve alarm sounds. These are the kinds of applications we're looking toward."
