Why Certain Sounds Terrify Us (And How Indie Filmmakers Can Use Them)

When it comes to horror, it’s rarely the visuals that hit hardest, it’s the sound. That deep rumble, that sudden high screech, the pregnant silence before a scream; these auditory cues bypass conscious thought and go straight for your nervous system.

In this post, we’ll dig into the psychology and biology behind why certain sounds trigger fear, then turn that theory into practical techniques you can use in your own indie film sound design work.

The Psychology Behind Sound in Film & Fear

Infrasound, Low Frequencies & the Unseen Tremble

• Infrasound refers to frequencies below ~20 Hz; technically under human hearing’s normal range. But even when we can’t consciously hear them, these frequencies can register as vibrations or pressure and stir unease.

• One experiment inserted a subtle 17 Hz tone into classical music without telling the audience. About 22% of listeners reported feeling “uneasy,” chills, sorrow, or revulsion, even though they didn’t consciously detect the tone.

• Low-frequency sounds (often in the 10–200 Hz band) have long been associated with danger signals: think growls, distant thunder, earthquakes. Our mammalian brains seem wired to register these frequencies as a primal “something’s off” cue.

• In human studies, exposure to moderate levels of low-frequency noise has been linked to reduced concentration, impaired attention, and mental fatigue.

• It’s not universal, some people are more sensitive to low frequencies and experience headaches, perceived pressure, or discomfort more acutely.

Takeaway for sound designers: Even if a low-frequency tone is inaudible, it can be felt, so use it with intent. Subtle rumbles or droning can pull the audience into tension before they even register it consciously.

High Frequencies, Dissonance & Acute Alarm

While low frequencies tug at your base anxiety, high frequencies (shrill strings, glass shattering, screeching brakes) hit faster and sharper. They often trigger fight-or-flight responses more immediately.

In horror films, high-pitched sounds are used to spike tension. Think of Bernard Herrmann’s stabbing violins in Psycho (the famous shower scene) where the rapid, dissonant strings feel like stabbing blades.

The contrast between quiet (or rumble) and sudden high tones is where the fear lives. The listener doesn’t hear the attack coming, but when it arrives, it jolts.

Frisson, Looming, and Spatial Movement

• Frisson is that chill-down-the-spine feeling you get from certain musical or sound cues, often when a sound seems to loom or approach you. One study found that binaural (3D positional) sounds moving around the head can intensify frisson compared to static audio.

• Our brains are sensitive to interaural level differences (volume differences between ears) and movement in space. When a sound seems to shift or get closer, our bodies react even if our conscious mind isn’t sure why.

Use this in horror: Drag a sound from quiet to loud, left to right, or back-to-front. Let the audience track something coming. Don’t just land the scare, make them anticipate it.

Techniques from Horror Sound Designers You Can Steal

To turn these psychological insights into real design moves, here are techniques discussed by sound pros, which you can hear more about in the full podcast episode:

• Pitch bending / automation: Slowly bend sounds upward or downward to create tension or disorientation.

• Layering. Combine a low rumble + mid-range texture + high screech for “hybrid fear.” Don’t rely on one sound trick; build a full "sandwich".

• Deliberate mismatches. Pair an ominous visual with a “wrong” sound (e.g. playful music, reverse FX) to create unease.

• Dynamic editing (J-cuts / L-cuts). Let audio carry over scenes or preempt visual cuts, so sound leads mood shifts.

• Silence. Let the listener’s own hearing leap into the gap. The tension in the quiet is as powerful as the noise.

• Alternate field recordings. Take real-world low-end vibrations (wind, hum, machinery) and pitch-shift or stretch them.

• Delayed reveals. Build a quiet drone, then gradually introduce small anomalies (a twig snap, distant echo), then surge.

StudioBinder, for example, suggests simple layers like a heartbeat or whispering wind to build dread in quiet scenes.

How to Use This in Your Own Indie Film Sound Design

Here’s a step-by-step mini-process (plus tips) to turn these concepts into practice:

Step	What to Do	Pro Tip
1. Build a low rumble foundation	Layer a sub-bass drone or muted synth around 20–60 Hz	Keep it subtle, too loud and it becomes felt rather than heard
2. Seed micro-anomalies	Add quiet hisses, distant creaks, shifting wind, or water drips	Let these evolve slowly (bonus points if visual cues or cutaways align!)
3. Introduce motion / directionality	Pan or shift elements in space, or move volume over time	Use automation so the movement feels natural
4. Apply contrast	Insert silence or near-silence before surging into a high-frequency spike	The quieter the lead-in, the sharper the impact
5. Edit with intention	Use J-cuts and L-cuts so audio leads or lags visuals	Let the sound "lie" if it misleads; it’s part of the scare
6. Listen in mono / check your low end	Many viewers (mobile, headphones) collapse stereo	If your low frequencies disappear in mono, re-balance

Also: Experiment in short form! Try creating a 5–10 second “audio sketch” first by building just the sound before layering picture. This can reveal weak spots you wouldn’t notice once visuals enter.

Final Thoughts & Takeaways

• Use low-frequency horror sparingly. Overuse dulls the effect.

• Be cautious of listener comfort; extremely powerful infrasound or too much sub-bass can cause nausea or headaches. Some low-frequency exposure studies (see above) report discomfort in sensitive subjects.

• Always test your mix on small speakers, headphones, and mono; fear should translate through all playback systems.

• Imperfections are your friends. Slight noise, hiss, or texture gives life. Over-cleaned tracks often fall flat.

  • This isn't an excuse to leave glaring mistakes in your audio, just a reminder to avoid making your location audio sound like it came from a studio.