A Northeastern Professor Reveals the Science of Scary Sounds

Professor Michael Epstein studies how horror films manufacture fear with audio.

Picture this: A girl walks alone down a long, creaky hallway. The lights are off, her pace is slow, and she’s inching towards the shadows. What sort of music is playing in the background?

Almost without a doubt, it’s the classic “slow build:” a steady increase in discordant sounds. In fact, this trope is present in just about every modern scare scene, says Michael Epstein, a professor of communication sciences and disorders at Northeastern University.

“There’s a very small library of sounds that every single major horror film draws from,” he says. “Very precise noises trigger human fear and discomfort, and we just use them over and over again.”

Epstein, who directs Northeastern’s Auditory Modeling and Processing Lab, has been researching human reactions to alarm sounds and film scores for nearly 17 years. A musician himself, he set out to understand how scary movies evoke extreme physiological responses—and found that it’s actually very simple.

“Common musical intervals, changed slightly to create dissonance, are immediately disconcerting,” Epstein explains. “The more a film uses them, the more uncomfortable we are.”

While it’s no surprise that mainstream, big-budget filmmakers manufacture their sound for guaranteed thrills, Epstein says he was surprised to learn just how little most films stray from the formula. “You could probably write software that lets you pick the level of tension for a certain scene, and it would score it for you,” he says. “In a purely functional way, I’m not even convinced humans could do it better.”

He found that these patterns saturate modern “jump” scenes, during which a steady increase in tempo, volume, and pitch leads to a pre-packaged fight-or-flight response. “It’s always build-up, build-up, pause, jump,” he says. “Just listening to the music, I could probably hit a marker exactly where the scare will happen.”

It’s precisely because fear has become so mass-manufactured that Epstein believes we may actually be positioned for a Hitchcockian revival, harkening back to the days of wind chimes and atonal floor creaks. “People are becoming desensitized to the formula,” he says. “When 90 percent of the film relies on loud, obtrusive swelling for a cheap effect, it’s hard to get people to react.”

Northeastern students corroborated Epstein’s claim when, on a survey he created, they pointed out specific chord structures meant to signify fear. The students collectively identified the most common combinations as “associated with scary films, but not actually scary.”

“We need new ways to create tension and discomfort,” Epstein says, calling for more subtle, contrasting music. “How are we going to keep pushing these dramatic elements to keep the genre fresh?”