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Sound can have a profound impact on human psychology. From survival instincts triggered by loud, alarming noises to the subtle but unnerving tones that raise anxiety levels, certain sounds have a chilling effect on our brains. In this article, we will explore the scariest sounds in the world, explaining why they provoke such intense reactions by delving into sound frequencies, psychology, and the brain’s instinctual responses.
However, let's first put all this horrifying noise into a psychological perspective.
Cinematic Approaches to Terrifying Sounds
In horror cinema, sound design is one of the most powerful tools for evoking fear and suspense. Filmmakers use a range of techniques to manipulate sound in order to intensify the emotional experience. Low-frequency noises like rumbles or deep drones are frequently employed to create a feeling of unease, even if the source of the sound is not immediately clear. These low-frequency tones are barely noticeable but evoke a physical sensation that amplifies fear and anxiety. Horror directors also frequently use silence, allowing quiet moments to build suspense before a sudden, loud noise (a jump scare) shocks the audience.
Additionally, non-linear sound—noises that don't follow predictable patterns, like distorted whispers or dissonant music—can disorient the viewer and trigger discomfort. In classics like The Shining and Psycho, screeching violins or eerie tonal shifts heighten the emotional intensity by creating auditory stress. Filmmakers also play with diegetic and non-diegetic sound. For example, a character might hear a creaking floorboard, which is diegetic (part of the film’s world), but this sound may be amplified or distorted for the audience’s experience, making it unnerving. Horror films rely on exploiting these auditory cues to turn otherwise mundane sounds into instruments of fear, immersing the viewer into the film’s atmosphere.
Why People Love Watching Horror Films
Despite the fear and anxiety horror films provoke, many people are drawn to them. Psychologically, watching horror allows individuals to experience fear in a controlled environment. This sense of control is critical because the brain knows the fear is simulated and can safely explore intense emotions without real danger. The amygdala—responsible for processing fear—becomes highly active during horror scenes, releasing adrenaline and endorphins, the same chemicals associated with the fight-or-flight response. This surge of adrenaline provides a thrill, which some people find exhilarating. The body also produces dopamine, giving the brain a rewarding sensation once the threat (in this case, the horror film) is over.
Moreover, horror films give viewers a chance to confront their anxieties indirectly. Some psychologists suggest that horror movies offer a form of emotional catharsis, allowing people to process deep-seated fears or societal issues in a metaphorical sense. For example, a zombie movie might reflect fears of pandemics or societal collapse. Others enjoy horror because it acts as a ‘safe scare,’ where individuals can bond over shared experiences of fear, reinforcing social connections. Paradoxically, watching something terrifying in a group setting can actually foster feelings of safety and community. The combination of emotional release, thrill-seeking, and social bonding explains why horror films have a devoted fan base, despite their often terrifying nature.
And if you dare to continue, let's proceed with the chart. Here are the top 15 most terrifying sounds.
1. Screams of Distress
Screams—whether from a human or animal—are universally terrifying. They trigger an instant fight-or-flight response, as the brain associates screams with danger or distress. The reason screams are so alarming lies in their specific frequency range (between 30 and 150 Hz) and the rough, unpredictable modulations that make them unsettling. Evolutionarily, we’re wired to react to these high-pitched, piercing sounds, as they may signal an immediate threat.
Effect on the brain: When we hear a scream, our amygdala—the brain’s fear-processing centre—lights up, triggering a surge of adrenaline and cortisol. This rapid response prepares the body to either escape the situation or confront the danger head-on.
2. Creaking Doors or Floors
The slow, deliberate creak of a door or floorboard is synonymous with suspense and dread in horror movies. These sounds are often eerie because they are low-frequency, unstructured noises, which our brains struggle to predict. The unpredictability of creaking sounds creates a sense of foreboding, as we associate these noises with something sneaky or threatening lurking nearby.
Effect on the brain: Low-frequency sounds activate the brain's fear circuits, particularly in the subcortical regions, making us feel uneasy. Our brain interprets creaking as a potential sign of something or someone moving stealthily, heightening our awareness of the environment.
3. Whispers in the Dark
Whispers, especially in dark or unfamiliar surroundings, can be deeply unsettling. Whispered sounds often convey secrecy or an unknown presence and are usually amplified in quiet environments. Due to their soft volume, whispers force us to focus harder on the sound, making us more aware of our vulnerability.
Effect on the brain: Whispering activates the auditory cortex and engages the brain's mirror neuron system, which makes us instinctively try to understand the message. The ambiguity of whispers, paired with their close proximity to our ears, creates a sense of intimacy that can feel threatening.
4. Infrasonic Frequencies
Infrasound—sound waves below 20 Hz—cannot be heard but can still be felt by the body. These low-frequency sounds are often associated with natural disasters, such as earthquakes or volcanic eruptions, and are linked to a sense of dread. Infrasound has been known to induce feelings of nausea, unease, and even hallucinations in some cases.
Effect on the brain: Infrasonic waves can resonate with parts of the human body, including the eyes and internal organs, which may explain why people report feelings of terror or paranormal experiences when exposed to them. The brain may interpret these sensations as a sign of danger, even though we can't consciously hear the sound.
5. Sudden Loud Bangs or Explosions
Sudden, loud sounds—like bangs or explosions—are designed to startle us. These noises trigger the brain's survival mechanisms, as sudden changes in sound levels are often associated with immediate threats. This is why horror films use jump scares effectively: they exploit our brain's tendency to react quickly to abrupt noises.
Effect on the brain: The loudness and unexpectedness of bangs activate the sympathetic nervous system, causing a surge of adrenaline. The body prepares for fight or flight within milliseconds, making these sounds both physically and mentally jarring.
6. The Hum of Electrical Appliances (Electromagnetic Noise)
Low, continuous humming, often from electrical devices or machinery, can make people feel unsettled over time. This sound is often monotonous and persistent, making it difficult for the brain to ignore. Some scientists believe this type of noise disrupts the brain's natural rhythms and can cause fatigue, anxiety, or even headaches.
Effect on the brain: Constant low-frequency sounds can overstimulate the brain’s auditory system, creating a form of sensory overload. The inability to escape from these frequencies can lead to discomfort and unease, contributing to a general sense of anxiety.
7. Animal Growls
The deep, guttural growl of a predator is one of the most primal sounds that can trigger fear in humans. Growls signal aggression or imminent danger, and our brain instinctively reacts to protect us from potential threats. The low frequencies of growls, coupled with their rough, vibrating textures, make them sound menacing.
Effect on the brain: Growls stimulate the amygdala and release stress hormones like cortisol and adrenaline. These sounds are linked to survival instincts, and our immediate response is to escape or prepare to defend ourselves.
8. Baby Crying
Though not typically associated with horror, the sound of a baby crying can evoke intense emotional responses. Crying triggers a caregiver instinct, but in certain situations—like when it’s persistent or in a quiet, dark space—it can create feelings of tension or helplessness.
Effect on the brain: Baby cries activate the brain’s limbic system, especially the anterior insula, which deals with empathy and emotional responses. Prolonged exposure to this sound can induce stress and anxiety, particularly if the cries can't be comforted.
9. High-Pitched Feedback or Screeching
Feedback or screeching sounds, such as those from a microphone, are disturbing due to their high pitch and irregularity. These sounds fall into a frequency range that is harsh on the ears and difficult for the brain to process, making them uncomfortable and even painful.
Effect on the brain: High-pitched noises are processed as distress signals by the auditory cortex, which is why they can cause physical discomfort and anxiety. The brain interprets these sounds as being sharp or harmful, prompting a protective response to distance ourselves from the source.
10. Rumbling Thunder
The low, distant rumble of thunder often evokes fear because it signals the approach of a storm, which could bring danger. The deep, rolling sound waves of thunder, especially when prolonged, can create a sense of impending doom, as they signal the presence of a force beyond human control.
Effect on the brain: The brain associates thunder with danger due to past experiences with storms. The deep sound waves resonate with the body's core, which can stir feelings of vulnerability and primal fear, even when we are safe indoors.
11. Footsteps in an Empty Hallway
Hearing slow, deliberate footsteps in an empty hallway can be one of the most unnerving experiences, especially when the source of the sound is unknown. The rhythmic but irregular pattern of footsteps can induce anxiety, as the brain tries to identify whether the sound is friend or foe.
Effect on the brain: Footsteps trigger heightened alertness and an immediate desire to locate the source. When the source of the sound is ambiguous, the brain's anxiety centres activate, creating a sense of dread.
12. Distorted Voices
Distorted voices, whether through technology or by unnatural means, have a particularly unsettling effect on people. This is because the brain is tuned to understand human speech patterns, and when those patterns are altered or disrupted, it becomes confusing and disturbing.
Effect on the brain: Distorted voices create a cognitive dissonance that makes it difficult for the brain to process the sound as human. This confusion triggers a feeling of unease, as the brain perceives the altered voice as unnatural or threatening.
13. Chains Clinking or Metallic Sounds
The sound of chains clinking or dragging metal is often associated with imprisonment or confinement, which invokes a deep sense of fear. These sounds are often slow, methodical, and heavy, reinforcing their association with struggle or danger.
Effect on the brain: Metal clinks or dragging sounds activate the brain's association networks, linking the sound with images of entrapment or danger. This is reinforced by cultural depictions of chains as symbols of imprisonment.
14. Static Noise (White Noise)
Though white noise can be calming in small doses, prolonged exposure to static or hissing sounds, like that from untuned radios or TVs, can evoke anxiety or discomfort. The randomness and lack of pattern make it unsettling to the brain.
Effect on the brain: Static noise lacks rhythm or predictability, which prevents the brain from relaxing. This sound can create mental fatigue as the brain attempts to make sense of the noise, causing anxiety over time.
15. Heartbeat Sounds
The sound of a heartbeat, especially if amplified or irregular, can become increasingly eerie when heard out of context. This sound mimics the body's internal rhythm but, when amplified or isolated, it can create an unsettling reminder of our vulnerability.
Effect on the brain: Hearing an irregular or amplified heartbeat can activate the brain's anxiety centres. We are subconsciously attuned to the regular rhythm of our own heart, so when that rhythm is altered or emphasised, it triggers feelings of panic or discomfort.
Additional Reading Resources:
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Braund, Martin, The Soundscape: Our Sonic Environment and the Tuning of the World, 1993.
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Levitin, Daniel J., This Is Your Brain on Music: The Science of a Human Obsession, Penguin Books, 2006.
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Kumar, S., The Neural Bases of Aversive Auditory Stimuli, Oxford University Press, 2021.
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Schafer, R. Murray, The Tuning of the World, University of Pennsylvania Press, 1977.