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Brown note

The brown note refers to a hypothetical infrasonic frequency, typically below 20 Hz, believed to induce involuntary defecation in humans by causing vibrations that resonate with the intestines.^[1] This concept originated as an urban legend, with anecdotal claims dating back to discussions of sonic weapons in military contexts during the mid-20th century, but it gained widespread popularity through a 2000 episode of the animated series South Park, which depicted the note as a tool for crowd control.^[2] Despite its cultural notoriety, scientific investigations have consistently debunked the idea, finding no evidence that any specific low-frequency sound triggers bowel movements.^[1] In a 2003 study conducted at a concert in London, researchers exposed over 700 attendees to 17 Hz infrasound at high volumes, resulting only in reports of unease and chills rather than any gastrointestinal effects.^[3] Similarly, the television program MythBusters tested frequencies as low as 5 Hz on participants in 2005, observing discomfort and nausea but no instances of defecation.^[4] Experts in acoustics, such as Dr. Geoff Leventhall, have emphasized that while infrasound can produce physiological responses like anxiety or disorientation at intense levels above 130 dB, the notion of a "magical frequency" for bowel control lacks empirical support and stems from misconceptions about bodily resonance.^[1] Overall, the brown note remains a persistent myth in popular culture, illustrating the interplay between sound science and folklore, with no verified applications in reality.

Origins and Definition

Historical Origins

The term "brown note" first appeared in a 1974 satirical article in New Scientist, which spoofed a Victorian-era instrument called the Giant Collophone allegedly producing a tone that caused mass discomfort and diarrhea during a performance.^[1] It emerged more widely in the 1990s as a metonym for the typical color of human feces, describing a purported infrasonic frequency that induces involuntary defecation through bodily resonance.^[5] This urban legend gained initial traction amid growing interest in low-frequency sound effects, blending folklore with early pseudoscientific claims about audio's physiological impacts, including rumors of its use in Aphex Twin's 1991 Glastonbury set.^[6]^[1] The myth's possible roots lie in military legends from the Cold War era, where unverified claims circulated about experiments with infrasound as a non-lethal sonic weapon for crowd control.^[7] During the 1960s and 1970s, popular press reports exaggerated the potential of infrasound to cause disorientation, nausea, and other incapacitating effects, fueling speculation that such technologies could target the human digestive system to disrupt bowel control.^[7] These anecdotes, often tied to declassified or rumored U.S. and Soviet research programs, provided a shadowy backdrop for the brown note's conceptual foundation, though no documented evidence links them directly to fecal incontinence.^[8] By the late 1990s, the brown note had evolved into an internet hoax, amplified by anonymous posts on early online forums and bulletin boards that popularized the idea of a specific 5-9 Hz frequency as the trigger for the effect.^[6] These discussions, predating mainstream media portrayals, often framed the note as a hidden acoustic secret with humorous or alarming implications, spreading rapidly through digital word-of-mouth.^[5] The timeline aligns with the broader rise of urban legends in cyberspace, where unverified sonic myths like this one thrived before gaining visibility in pop culture.^[1]

Description of the Myth

The brown note refers to a purported low-frequency infrasonic tone, typically in the range of 5 to 9 Hz, believed to resonate with the human digestive system and induce immediate, uncontrollable defecation in listeners.^[6]^[9] This acoustic phenomenon is described as creating vibrations that disrupt bowel control through resonance within the intestines, leading to spontaneous loss of fecal matter without warning. Variations of the legend portray the brown note differently across contexts; some accounts depict it as a weaponized sound deployed in non-lethal crowd control devices, such as acoustic cannons designed to incapacitate targets by forcing involuntary defecation or vomiting.^[10]^[11] Other iterations suggest it occurs as a natural phenomenon or emerges from extreme bass frequencies in music and audio equipment, with claims that loud rock concerts have inadvertently triggered the effect on audiences.^[12] The concept is classified as a myth due to its status as unsubstantiated urban folklore, persisting primarily through anecdotal tales and popular culture rather than verified accounts.^[13] A common misconception in the legend is that the brown note universally affects all individuals equally, irrespective of personal hearing capabilities, physical health, or exposure intensity, implying a one-size-fits-all physiological response to the tone.^[1]

Scientific Basis

Effects of Infrasound on the Human Body

Infrasound refers to acoustic vibrations with frequencies below 20 Hz, which are generally inaudible to the human ear but can propagate long distances through air and solid structures, inducing physical vibrations in the body.^[14] These low-frequency waves couple with the body's natural oscillatory modes because their wavelengths align with human dimensions, leading to mechanical interactions that bypass auditory perception and directly affect tissues and organs via mechanotransduction processes. Studies on industrial workers exposed to low-frequency noise, such as in aviation and manufacturing environments, have documented physiological effects from prolonged exposure.^[14] Known physiological effects of infrasound include vibration-induced sensations of nausea, disorientation, and anxiety, often reported at levels as low as 20 dB above the hearing threshold, where individuals experience ear pressure and unease without cardiovascular alterations in short exposures.^[15] Organ resonance plays a key role; for instance, the human eyeball resonates around 18 Hz, potentially causing visual distortions, while the chest and abdominal cavities exhibit principal resonances between 5 and 10 Hz, leading to discomfort from synchronized organ movement.^[16]^[17] Whole-body vibration in this range can also induce gastrointestinal discomfort through altered motility, though this stems from general vibroacoustic stress rather than targeted organ excitation.^[18] Human responses to infrasound vary significantly due to factors such as posture, where seated or bent positions shift the body's principal resonance from approximately 5 Hz to higher values like 8 Hz.^[19] Exposure duration further modulates effects, with acute exposures causing temporary unease and chronic ones leading to more severe physiological effects in susceptible populations.^[14] There is no single universal frequency that uniformly affects bowel control across individuals, as resonance depends on these personal and situational variables.^[14]

Evidence For and Against the Brown Note

No peer-reviewed scientific studies have confirmed the existence of a specific infrasonic frequency capable of inducing involuntary bowel movements in humans.^[9] Anecdotal reports of such effects are typically attributed to placebo responses, psychological suggestion, or coincidental gastrointestinal discomfort rather than a direct acoustic cause.^[5] Human bowel control is primarily regulated by the enteric nervous system, autonomic nervous inputs, and voluntary muscular sphincters, which coordinate defecation through complex neural signaling and do not respond directly to airborne sound waves.^[20] Infrasound-induced resonance in the body, even at frequencies around 5-9 Hz purportedly targeted by the brown note myth, lacks the intensity and precision required to override these neural and muscular mechanisms, as the human torso's acoustic coupling to low-frequency sound is too inefficient for such targeted disruption.^[21] Research on infrasound in military applications, such as Long Range Acoustic Devices (LRAD), demonstrates effects like auditory discomfort, nausea, and temporary disorientation at high intensities, but no evidence of defecation or gastrointestinal evacuation.^[22] Similarly, medical studies on infrasound exposure show alterations in gastric motility and myoelectrical activity, primarily in animal models, leading to symptoms such as reduced blood flow or contractility changes, yet without reports of involuntary bowel release in humans.^[23] The persistence of the brown note myth likely stems from misconceptions about vibroacoustic phenomena, where intense low-frequency sounds can produce visceral sensations or "rumble" in the abdomen, exaggerated in popular culture to imply control over bodily functions.^[13] This confusion is compounded by real but unrelated infrasound effects, such as unease or pressure, which do not extend to the specific defecation outcome claimed.^[24]

Experimental Investigations

MythBusters Experiment

The MythBusters television series examined the brown note in the episode "Brown Note," which aired on February 16, 2005, during season 3.^[4] To test the myth, the hosts constructed a specialized subwoofer array consisting of twelve Meyer Sound 700-HP cabinets, modified for enhanced low-frequency output and arranged in a three-high ring formation facing inward. This setup, powered by a SIM 3 audio analyzer, was capable of producing tones from 5 Hz to 20 Hz at sound pressure levels exceeding 120 dB in the center. The apparatus was deployed in an open parking lot to minimize environmental interference.^[25] Volunteers, including co-host Adam Savage, were positioned at the array's center within a portable chamber for isolation. The procedure employed a double-blind protocol, where participants endured randomized sequences of infrasonic exposure or silence, lasting up to several minutes per trial. Physiological monitoring included heart rate, blood pressure, and bowel activity via rectal sensors to detect any involuntary contractions or defecation. Multiple frequencies within the 5-20 Hz range were tested at varying intensities to cover potential "brown note" candidates.^[26] No participants experienced loss of bowel control across the trials, despite the extreme volumes causing sensations of vibration, nausea, and mild discomfort. The team concluded the myth was busted, attributing any anecdotal reports to placebo effects or unrelated physiological responses rather than specific infrasound-induced defecation.^[26]

Other Scientific Tests

In the 1990s and 2000s, U.S. military research explored infrasound as a potential non-lethal weapon, with studies indicating that low infrasonic frequencies could induce unease, nausea, and disorientation in exposed individuals, but no evidence of bowel control loss was observed as a reliable or targeted effect.^[22] For instance, reports on high-intensity infrasound exposure highlighted physiological responses such as vertigo and anxiety, yet these effects were deemed minimal and challenging to weaponize effectively due to the high energy required and lack of targeted incapacitation.^[27] Similar investigations by NASA focused on infrasound detection and propagation rather than direct human effects, contributing to broader understanding of low-frequency acoustics without confirming any resonant defecation mechanism.^[28] A notable experiment occurred in 2003 at the Purcell Room in London, organized by psychologists Richard Wiseman and Richard Lord. During a concert titled "Infrasonic," approximately 700 attendees were unknowingly exposed to 17 Hz infrasound at around 100 dB, embedded in the music. Post-concert surveys revealed that 22% of participants reported unusual feelings of anxiety, chills, or sorrow, with some attributing it to the venue's atmosphere, but no gastrointestinal effects such as defecation were noted. This study supported the idea that infrasound can evoke emotional and physiological unease without affecting bowel control.^[3] Academic studies in the late 1990s extended low-frequency research to psychological phenomena, such as Vic Tandy and Tony Lawrence's 1998 investigation, which identified a 19 Hz standing wave in a laboratory environment causing feelings of fear, visual distortions, and unease among occupants, attributed to resonance with the human eyeball.^[29] This work suggested that infrasound in the 18-19 Hz range could produce sensory anomalies and emotional distress, prompting further exploration of low frequencies' role in perceived hauntings, though no gastrointestinal impacts like those in the brown note myth were reported. Comprehensive reviews of low-frequency noise effects, including those up to the early 2000s, found no corroboration for bowel resonance leading to defecation in gastroenterology or related medical literature.^[30] Informal experiments by audio engineers in the 2010s, often using high-powered bass amplification rigs to generate sub-20 Hz tones, documented sensations of bodily vibration and mild discomfort among participants, but failed to replicate any specific involuntary defecation. These tests, typically conducted in controlled studio settings with frequencies below 10 Hz at intensities exceeding 120 dB, emphasized physical rumbling over targeted physiological disruption. Key limitations in these investigations include ethical restrictions on exposing human subjects to extreme infrasound intensities, which could risk permanent harm, and the prevalence of small sample sizes that limit generalizability. Most studies relied on short-duration exposures with fewer than 20 participants, hindering robust conclusions about rare or threshold-dependent effects like those hypothesized for the brown note.

Cultural Impact

In Popular Media

The brown note has been prominently featured in animated television as a comedic plot device, most notably in the South Park episode "World Wide Recorder Concert" (Season 3, Episode 17, aired January 12, 2000), where the character Eric Cartman discovers a specific recorder tone—dubbed the "brown noise"—that induces involuntary defecation in listeners.^[2] In the episode, Cartman weaponizes the sound during a global school concert organized by the fictional Pox Network, leading to widespread chaos as participants and viewers lose bowel control simultaneously.^[31] This portrayal exaggerates the myth for satirical effect, tying it to themes of childish rebellion and media sensationalism. While direct references in live-action film are scarce, the concept appears in niche works like the 2020 short film Brown Note, directed by Louie Gallagher, which follows three friends on a quest to locate and test the legendary frequency, blending humor with mock-documentary style to explore the urban legend's absurdity.^[32] The trope has also influenced broader sonic weapon narratives in sci-fi comedies, though often without explicit naming, contributing to indirect nods in films emphasizing low-frequency sounds as humorous or disruptive elements. In literature and comics, the brown note surfaces primarily through discussions of urban legends rather than narrative integration. It is referenced in anthologies compiling modern folklore, such as those examining acoustic myths and their psychological appeal, where it exemplifies sensory overload tales that blend pseudoscience with bodily humor.^[1] In graphic novels, a literal interpretation appears in Warren Ellis's Transmetropolitan series (1997–2002), featuring a "bowel disruptor" handgun with settings like "loose" and "prolapse" that mimics the note's effects as a non-lethal crowd-control tool in a dystopian future.^[33] These depictions, particularly in early-2000s animation and internet-shared clips, have perpetuated the myth's cultural staying power by leveraging humor to make the grotesque relatable, ensuring its endurance in online memes and discussions well into the post-2000s digital era.^[34]

In Music and Sound Design

In music production, particularly within electronic dance music (EDM), producers often incorporate sub-bass frequencies in the 20-40 Hz range to create a visceral physical impact, such as vibrations felt in the chest and body, enhancing the immersive experience without any relation to the brown note myth's alleged defecatory effects.^[35]^[36] Brown noise, characterized by its deep rumbling quality due to a 6 dB per octave power decrease, is sometimes used in electronic tracks for atmospheric backgrounds or to mask low-end rumble, providing a textural layer in genres like dubstep or ambient.^[37] In sound design for films and games, low-frequency sounds approximating infrasound are employed to build tension and unease, as seen in horror scores where subtle rumbles evoke primal fear responses. For instance, the Paranormal Activity series (2007 onward) is rumored to integrate infrasound-like elements in its soundtrack to heighten perceptions of the supernatural, though the exact frequencies remain below audible thresholds for full effect.^[38]^[39] Synthesizers and digital audio workstations facilitate this by generating simulated low frequencies through oscillators and low-frequency oscillators (LFOs), allowing designers to craft sub-20 Hz tones for atmospheric dread without requiring physical infrasound equipment.^[40] At live music events like festivals, powerful sub-bass systems deliver low frequencies that can amplify physical sensations, with reports noting increased bodily effects from prolonged exposure during bass-heavy sets; however, standard equipment limitations typically prevent reproduction of true infrasound below 20 Hz. Humorous references to the brown note persist in music circles, including the naming of audio production company Brown Note Productions after the legend, which specializes in high-powered sound systems for concerts and festivals.^[41] Additionally, niche bands like the Brown Note have adopted the term for their punk and experimental acts, turning the myth into a playful motif in underground scenes.^[42]

References

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