Aggression

Mimic the acoustics of a threatening sound source


“Holy crap that growling guitar is like a punch in the face. Makes the hair on my arms stand up.”   –Listener comment

An Aggression pattern is when you mimic the acoustics produced by dangerous natural disasters, or the vocalizations people and animals produce when they want to sound hostile. These threatening sounds have consistent, distinct auditory cues: non-linearities (distortion) resulting from vocal strain, high amplitude modulation rates (acoustic roughness), descending pitch contours, infrasound, and low fundamental frequencies. The more abruptly you introduce aggression cues into your music, and the more you intensify the acoustic properties that distinguish them, the more likely audiences are to experience chills.

An Aggression pattern can trigger a frisson-inducing fear response by matching a danger schema, or auditory stereotype, in our memory that helps us efficiently respond to sounds indicating hostility.

When we hear aggression cues, our brain puts them on a fast track relative to other sensory information. The amygdala quickly prompts the release of chemicals in our brain (transmitters like dopamine, serotonin, and norepinephrine) and body (hormones like adrenalin and cortisol) that signal something important is happening. This prompts us to search our environment for the cause of our sudden, heightened arousal. Our brain determines the meaning of this heightened arousal by attempting to match it with a schema in our memory. Schemas help us more efficiently respond to stimuli we have previously associated with important sensations like danger. Recent research confirms that humans can reliably distinguish aggression cues from similar auditory cues denoting fear or other forms of heightened arousal.

A common feature across aggression cues is low, rough pitch, often involving the vocal fry register in human vocalizations. Given that body size is generally associated with the lowest possible frequency an individual can produce, humans and animals lower the pitch of their voice when they want to appear threatening or intimidating (think the over-the-top Batman voice from the Dark Knight trilogy). In mammals, lower pitched notes also tend to become noisy due to the vibrations of the vocal fold membrane surrounding the glottis.

Our data indicates than when you create low-pitched sounds (generally <100Hz) with unusual frequency features called non-linearities – chaotic broadband energy, sidebands, and warbles that all appear between or outside the normal harmonics of a voice or instrument – this can often induce frisson in listeners. This method is effective because non-linearities are difficult to fake. It takes significant energy to strain the lower range of a sound system and produce non-linearities. For this reason, our brain generally trusts them as honest signals of hostile intent.

In chills-inducing passages, the most reliable techniques we see composers and performers using to achieve this method include:

  • Extended vocal techniques like fry screams and death growls 
  • Noisy busts including electric guitar entrances with heavy distortion, recorded animal roars, and car engines revs
  • Yelling, shouting, and grunting in lead vocals

Don’t interpret this to mean that any low-pitched growling will work. Our data suggests that when using this technique, it helps to:

  • Placement: Introduce these sounds at moments when listeners are distracted by the melodic movement (e.g. end of a cadence) 
  • Set-up: Precede these sounds with repetitive, lower-energy sections that enhance the contrast with the aggressive entrance
  • Follow-up: Leave a beat or two of rest after the entrance to allow space for a positive listener appraisal response

Our data indicates that when you create low-pitched sounds (generally <100Hz) with an unusual frequency feature called acoustic roughness – very rapid loudness fluctuation that we perceive as beating or rattling – this can often induce frisson in listeners. These guttural, gritty sounds are commonly referred to as growling. Growl-like sounds are effective for frisson because they are unusual. Given how rarely we encounter low-pitched acoustic roughness in nature, it is a reliable and attention-grabbing indicator of hostility.

In chills-inducing passages, some of the most reliable techniques we see composers and performers using to achieve this method include:

  • Growl-like instrumental sounds, especially low brass (e.g. trombones, baritone sax) and string instruments (e.g., distorted guitar, cellos) 
  • Recordings of growling animals
  • Varying the pace and width of amplitude modulation, especially in sustained vocal notes

Don’t interpret this to mean that any growl-like sound will give listeners chills. Our data suggests that when using this technique, it helps to:

  • Placement: Use leaps at the beginning of song or new section to make them especially conspicuous
  • Set-up: Pair leaps with reduced orchestration (often solo vocals), monophonic texture, and slower tempos to focus listeners on the melodic movement and prevent non-melodic distractions
  • Follow-up: Sustain growl-like sounds to create space for a positive listener appraisal response

Our data indicates that when you create non-linear glissandos that descend from low to very low pitch, this can often induce frisson in listeners. Researchers have confirmed that low pitch and falling pitch contours are consistent features of aggression vocalizations. Descending glissandos take advantage of this association, but further subvert our expectations by making us think – as the pitch descends – that we are hearing an even larger, and therefore more dangerous, sound source than we thought when we heard the start of the glissando.

In chills-inducing passages, some of the most reliable techniques we see composers and performers using to achieve this method include:

  • Long, slow glides over several seconds or short, accelerating glides that last less than a second
  • Synths, electric guitars, and double basses 
  • Subtly accelerate or crescendo during the glissando given that our ears are less perceptive of pitch changes at low frequencies

Don’t interpret this to mean that any low-pitch glissando will give listeners chills. Our data suggests that when using this technique, it helps to:

  • Placement: Use longer glides during exposed moments (i.e. when backing instrumental drop out or melody vamps) and shorter glides during transitions between sections or phrases
  • Set-up: Immediately precede these glissandos with a few seconds of flat melodic material (e.g., ambient background, vamp, held chord) to make them as jarring as possible
  • Follow-up: Follow descending glissandos with an immediate re-start of the melodic flow if a pop or rock song, or repeat the glissandos and follow them each time with flat melodic material if a soundtrack cue, to create space for a positive listener appraisal response

Our data indicates that when you create infrasound – vibrations below the range of human hearing (16-19Hz) that we experience as a subtle, disorienting rumbling sensation – this can often induce frisson in listeners. You typically “feel” these sounds more than you hear them.  Predators including tigers, lions, and elephants, as well as natural disasters including earthquakes, avalanches, and tsunamis, all produce sound in the infrasonic or lower sub-bass range. Our encounters with these threats makes us associate infrasound with danger. 

In chills-inducing passages, some of the most reliable techniques we see composers and performers using to achieve this method include:

  • Sounds in the lower sub-bass range frequently manipulated to irregularly wobble and vary in volume and “height”
  • Sub-harmonic singing entrances featuring extended techniques like basso profundo and Tuvaan kargyraa singing)
  • Nature samples like recordings of lion roars or thunder claps

Don’t interpret this to mean that any very low pitch will give listeners chills. Our data suggests that when using this technique, it helps to:

  • Placement: Feature infrasound at the very beginning of a piece, a prominent climax, or a prominent transition point, to make the infrasound as conspicuous as possible
  • Set-up: Precede a passage where you use infrasound with a distraction (e.g. unexpected harmonic move, new timbre entrance, or silent, pregnant pause) to make it as jarring as possible
  • Follow-up: Prolong the infrasound and fade in a melodic or rhythmic line over the top to re-assure listeners it is intentional and create space for a positive listener appraisal response

Our data indicates that when you feature abrupt, large downward shifts in pitch with fast-attack, concentrated acoustic energy, this can often induce frisson in listeners. This method is effective for two reasons. First, it takes advantage of our the fact that we associate low fundamental frequencies with large, potentially dangerous sound sources. Second, these drops tend to concentrate energy in the key frequency range that mirrors the resonant cavity of our ear (1-4kHz and especially 3-4kHz), making them especially piercing.

In chills-inducing passages, some of the most reliable techniques we see composers and performers using to achieve this method include:

  • Bass drops in EDM music featuring electronic instruments and samples
  • Sub-harmonic singing entrances featuring extended techniques like basso profundo and Tuvaan kargyraa singing)
  • Certain orchestral instrument entrances in low register, such as pipe organ, double bass, tuba, contrabassoon, and bass clarinet 

Don’t interpret this to mean that any loud bass drop will give listeners chills. Our data suggests that when using this technique, it helps to:

  • Placement: Immediately precede drops with a distraction – either a divergent riff, rise in frequency, or pause – that throws listeners off balance and makes the drop as jarring as possible
  • Pre-moment: Concentrate acoustic energy at the start the drop note and change the rhythm, tempo, and texture on the drop, to make it as conspicuous as possible
  • Post-moment: Quickly re-start the lead line after the drop to re-assure listeners the frequency shift was intentional and create space for a positive listener appraisal respons

Listen to thousands more example clips in our Frisson Database

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Frisson moment flagged by listeners

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Song Title – Artist Name