Can sound make you poop? You may have heard of the “brown noise” or “brown sound” – a particular low-frequency sound that is said to cause those who hear it to suddenly lose control of their bowels. There is no universally accepted definition of the brown noise. But there are plenty circulating on the Internet. Consider two definitions of the brown noise from the not-exactly-reliable UrbanDictionary.com:
“An oscillation of sound that causes the bowels to loosen. The brown noise is believed to be ninety-two cents below the lowest octave of E flat.” “The brown noise was discovered by the French, and tested as a weapon during WWII. It is a 12-14hz sound wave that, when played loud enough, relaxes your sphincter, causing loss of bowel control.”
The first is the definition used for a famous episode of South Park, entitled “Worldwide Recorder Concert,” where Cartman becomes fascinated with the brown noise and predictable mayhem ensues, occasioning many poop jokes. The second appears more scientific and even implicates the French (although usually it's the Nazis who get credit). A third definition comes from acoustics, and describes brown noise as sound made up of frequencies that move in a manner akin to Brownian motion. We're not going to worry about that third definition, but to truly understand the brown noise, we do need to delve into a tiny bit of acoustics.
The standard figure for human auditory perception is 20-20,000 cycles per second. This means that if an object vibrates between 20 and 20,000 times a second (Hz=cycles per second), your ears will perceive it as noise. After a few rock shows, airplane rides and close calls with jackhammers, most American adults can't hear much above 15,000hz.
On the lower end of our hearing, we almost never perceive a 20hz sound. Even before the vibration slows to 20 cycles a second (roughly an E-flat), we begin to feel the sound as vibration rather than just hearing it. Once the rate of vibration drops below 20hz, we can't hear it as sound at all; we only feel it as vibration. So when Cartman proudly announces that the brown noise is 92 cents below the lowest octave of E flat, he is saying that the brown noise is not a noise at all. It is subsonic vibration. In the second definition, the brown noise is somewhat lower, in the 12-14hz range, which would place the note somewhere between a G and an A, were an elephant or some other animal with better low-end perception than a human to inquire about the pitch.
The available brown noise stories can be found all over the apocrypha of military history. The most common story involves the Germans during World War II and it usually goes something like this: the Nazis experimented with pretty much every kind of imaginable weapon, and a brown noise generator was among a class of “sonic” weapons they devised. The plan was to use it in surprise attacks on both military and civilian targets. On the battlefield, you could momentarily overtake your opponent – and since the brown noise is very low-frequency vibration, it could hypothetically travel through tanks and other hard-to-reach places, thereby temporarily disabling the enemy. It could also be useful for civilian attacks to weaken enemy morale – as a form of what the Nazis called “worldview warfare” and what Americans now call psychological warfare.
Reports of research into the brown noise elsewhere generally fall under the much larger category of “acoustic weapons” and especially “infrasonic weapons,” or weapons that use particularly low-frequency sound. This body of writing usually lists defecation alongside a host of other “nonlethal” effects that include disorientation, vomiting, pain, hearing damage, and a host of other medical fallacies.
Much of this work is discussed in the military and civilian press in the context of crowd control. A 1969 book on crowd control mentions a “people repeller” that creates a 120-decibel shrieking sound. This hardly seems like a good way to control a crowd: people will more likely disperse if they are covering their ears in pain; similarly, it seems strange to argue that people will stand in place if they are fighting the urge to defecate. Of course, if they did defecate, perhaps they would then disperse more slowly. According to a 1997 Cornell University Peace Studies Program report, the U.S. Army Armament Research, Development, and Engineering Center (ARDEC) has experimented with infrasonic weapons as part of a “low-collateral damage” weapons program, but no brown noise research has been reported.
So for the Nazis and the Americans (and the British and the French, as it turns out), we have lots of research into infrasonic weapons, but no evidence of working brown noise generators, despite well-circulated rumors to the contrary. So we have to consider some reasons why no such machine has been built.
For one thing, it’s probably not physically possible. If you have a good home stereo with a lot of bass, you can try an experiment. Pick a song with a lot of low-end and crank the volume. At certain pitches, the wood objects in the room or the next room will vibrate in sympathy with certain low notes. That’s because every piece of wood has a resonant frequency. That exact frequency depends on both the grain of the wood and the size of the object. The same thing is true of our colons. Because there is some variance in the size and density of the human colon, there is no one, single resonant frequency for everybody’s colon.
Another reason that nobody has effectively created a brown noise that works for everybody has to do with motivations. Much of the talk about the brown noise has come around discussions of secret military operations, black helicopters, and alternative weapons systems. A brown noise could be used against civilians or soldiers, presumably. In fact, the hope usually extends beyond mere poop to uncontrolled vomiting and even shaking people’s internal organs apart. A Fortean Times article on infrasound (very low frequency) weapons quotes a 1978 Hungarian working paper that claimed that frequencies between 7 and 8hz caused flesh to resonate, and could conceivably shake people apart at high enough volumes. The article also mentions other attempts to conceive and build sonic weapons.
All this sounds scary until you consider two other properties of very low-frequency noises: they move in all directions at once, and they take a tremendous amount of energy to create. It takes most of my bass amp's 400 watts to create an audible sound at 40hz at a relatively low volume. It would be expensive and inefficient to trot an amplifier powerful enough to make a brown noise onto the battlefield. But the other problem is that even if it did work, the brown noise would radiate out in all directions at once. A brown noise weapon couldn't target the enemy. It would simply cause everyone within range to, well, you know.
The Fortean Times quotes acoustician Jurgen Altman, who argued in a 1999 presentation that acoustic weapons were basically impossible to construct: “I have found no hard evidence for vomiting or uncontrolled defecation, even at levels of 170 dB or more.” 170 decibels is extremely loud: a jet engine taking off is 150 decibels. If you don’t believe Altman, ask yourself the following questions: how many hipsters have shown up to rock or hip-hop shows wearing diapers? Does Best Buy include special seat covers for your car when they sell you the trunk-sized subwoofer? No? Then you have nothing to worry about. If the brown noise had been discovered, it would have been used at countless concerts and on countless recordings. By now, it would be a worn-out gimmick, just like the “hidden tracks” on your favorite CD. That’s right. If there was a brown sound, then music that causes us to defecate would have become as banal as the act of defecation itself. Luckily that hasn't happened.
What does the brown noise mean, and why does anyone care about it, even when the scientific evidence is so thin?
Here’s a story. One day in medical school, my friend Dan sits down with six other medical students for a short lecture on the human sphincter. In comes the professor, a small, serious man suitably dressed in blue jacket and bow tie. The professor speaks quickly, seriously and clinically and the students frantically take notes. He explains the sphincter in detail – how its three separate muscles work together, how it regulates the flow of waste out of the body, and the common medical problems associated with it. After going on for quite some time about how and why the sphincter works, the professor finishes with a simple insight “and so you see, this is why civilization is possible.”
Perhaps the brown noise is the fantasy of a culture or civilization folding in on itself. If you believe Dan’s bow tied medical school professor, a brown noise machine is a product of civilization that is designed to undermine the basis of civilization. It’s a twisted logic if you think about it: we use our elaborate science and knowledge of the human body to force other people to lose control of their bodies. And let’s face it, bowel control is right up there on the list of things you need in order to be a functioning person in modern life.
The brown noise could be an extension of an old story often told about sound media: a surprisingly large number of 19th century observers believed that spirits of the dead could travel through the telegraph, phonograph and radio. In the brown noise story, the “spirits” are no longer there, but it is now sound that takes people over on its own. Whether sounds carry the souls of the dead or merely physical force, they are said to inhabit us, to drive a wedge between our consciousness and our bodies.
Perhaps the brown noise captures the imagination in the ways other infrasound weapons have not because it leaves its victim intact, but with a little unwanted extra something. Sociologist Norbert Elias wrote that as everyday life became less dangerous, people’s thresholds of disgust, revulsion, fear and emotion expanded. Even though the brown noise isn’t actually heard, people imagine that it moves through their bodies against their will. The brown noise enters through the ear and exits through the rear.
Is it possible that a weapon that does not kill but merely causes discomfort and embarrassment is more intriguing and threatening than a device that actually kills people? Perhaps the most frightening line of thought is that it suggests a scenario where embarrassment is a fate worse than death – or at least worth comparing with death. Has war become so banal and so acceptable that its most fascinating and frightening dimensions are no longer the masses of dead, the “collateral damage,” but rather the bizarre side projects? Now there’s a scary thought.
We could also be more practical. A brown noise machine does present an interesting alternative to fiber supplements and laxatives. Perhaps it is best considered alongside the ultrasonic toothbrush – in the bathroom and not on the battlefield. To paraphrase Field of Dreams, “if you build it, they will go.” But that is a subject for another article.
