Halloween Hearing: What Makes Certain Sounds Scary?

Jack-o-lantern in window

What do the top rated horror movies all have in common?

They all have unforgettable soundtracks that bring about an instantaneous feeling of fear. As a matter of fact, if you watch the films without any sound, they become a lot less frightening.

But what is it regarding the music that makes it frightening? More specifically, if sounds are simply oscillations in the air, what is it about our biology that makes us respond with fear?

The Fear Response

With respect to evolutionary biology, there’s an evident survival advantage to the immediate detection of a hazardous scenario.

Thinking takes time, particularly when you’re staring a ravenous lion in the face. When every second counts, you don’t have the time to stop and process the information consciously.

Considering it takes a bit longer to process and contemplate visual information, the animal brain is wired to react to faster sound-processing mechanisms—a characteristic that offers survival advantage and has been selected for in the wild.

And that’s exactly what we see in nature: several vertebrates—humans included—produce and respond to harsh, nonlinear sounds and vocalizations when frightened. This yields a nearly instantaneous feeling of fear or anxiety.

But what is it about nonlinear sound that makes it alarming?

When an animal screams, it creates a scratchy, irregular sound that stretches the capacity of the vocal cords past their normal range.

Our brains have evolved to distinguish the properties of nonlinear sound as abnormal and indicative of life-threatening situations.

The fascinating thing is, we can artificially replicate a variety of these nonlinear sounds to get the same instantaneous fear response in humans.

So, what was once an effective biological adaptation in nature has now been co-opted by the movie industry to manufacture scarier movies.

Music and Fear

We all know the shower scene from the classic film Psycho, and it’s definitely one of the most frightening scenes in the history of cinema.

But if you watch the scene on mute, it loses most of its impact. It’s only once you incorporate back in the high-pitched screeching and bone-chilling staccato music that the fear response becomes fully engaged.

To demonstrate our natural aversion to this nonlinear sound, UCLA evolutionary biologist Daniel Blumstein carried out a study examining the emotional responses to two types of music.

Study participants listened to a collection of emotionally neutral scores and scores that incorporated nonlinear properties.

As expected, the music with nonlinear characteristics elicited the strongest emotional reactions and negative feelings. This response is simply an integral part of our anatomy and physiology.

Regardless of whether Hollywood comprehends this physiology or not, it knows intuitively that the use of nonlinear discordant sound is still the most effective way to get a rise out of the viewers.


Want to observe the fear response in action?

Listen to these 10 Essential Horror Movie Scores.

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