You've heard it before, probably a hundred times over already, from the mouths of noisicians (noise musicians): "I want to create sounds that will make people throw up, or shit their pants."
Sadly, unless they're talking about making a style of music that's so psychologically creepy that it causes sickness or insta-crapping, they don't know their science.
Sound is a simple set of vibrations, ranging in varying Hz (hertz = cycles per second) and dB (decibels = volume). Hertz can range from the negative field (say, -5 Hz) to as high as 1,000 MHz (megahertz, 106 Hz). Decibels range from 0 dB (absolute silence) to 1,000 dB (atomic explosions)—though decibels may go higher, only the explosion of Krakatoa (a volcano near Indonesia, where in 1883 it created the loudest known sound, which reverberated around our planet seven times and was detectable for five days) could surpass it.
The human ear can only pick up the sound field of 20 Hz through 20,000 Hz, whereas a dog's hearing range is 60 Hz to 45,000 Hz, and a cat's is 40 Hz to 85,000 Hz.
Any sound lower than 16 Hz is considered "infrasound," and is so low we tend to feel it, over hearing it. Sounds above the human limit of 20,000 Hz are considered "ultrasound," and are usually ineffective to us.
To get someone to poop their pants at one of your rockin' shows, you're gonna have to work with infrasound, but there's another catch: you're also gonna have to work with organic sound emitted by an item you use then and there, and not mechanical or pre-recorded sounds emitted by speakers, a PA, or any other sound system.
That's simple. All manufactured speakers are built with a range from 16 HZ to 16,000 Hz (the frame between infra- and ultrasound), so no matter how hard you try, your equipment just won't produce it.
Before I teach you how to actually decimate your audience's underwear, or destroy your fanbase, let me get into some more science.
Infrasound is naturally found all around you; from high winds, the ocean, and thunder, to natural disasters like earthquakes. Even a car traveling at 60 mph, with the windows slightly open, creates a frequency of 16 Hz at 112 dB—enough to make some drivers appear drunk.
The study of infrasound was put to practical use in the First World War, where infrasound detection equipment was used to locate where enemies were launching large artillery. It was later taken more seriously at Wright-Patterson Air Force Base in Dayton, Ohio throughout the early-'60s by Dr. Henning E. von Gierke (a Nazi scientist picked up by the U.S. in their Project Paperclip, and a member of the Acoustical Society of America), where he developed infrasound weaponry.
The previous WWI techniques—and later weapons—pretty much stayed a United States secret until 1965, when members of the French National Center for Scientific Research in Marseille began having headaches and feeling sick, only to find it was all caused by a large industrial fan that emitted an infrasonic sound, and began studying sounds and their effects on humans.
It was found that differing sound frequencies at differing volumes have detrimental effects on the human body, as well as the mind:
- 0 - 50 Hz above 140 dB can cause organs to rub against one another, internal bleeding, gag reflexes, respiratory trouble, mental breakdown, and fatigue.
- 50 - 100 Hz above 150 dB can cause headaches, choking, and visual blurring.
- 60 Hz at 150 dB causes coughing and substernal pressure.
- 70 Hz at 150 dB causes salivation, pain on swallowing, and lightheadedness.
- 100 Hz at 150 dB causes nausea, giddiness, and flushing of the skin.
The most dangerous of all infrasound (0 Hz - 16 Hz) is at 7 Hz, as low as 60 dB, which causes disassociation, impaired thinking, troubled breathing, and severe psychological trauma (including panic and psychosis). This sound range is dangerous simply because it is the range of our brain's alpha waves, so it can interrupt them.
At the same time, infrasound is medically beneficial, as doctors have used it to restore the sense of smell in patients, and helped stimulate ovulation in women. It also has a commercial use, as it's a feature in theaters' "Sensurround," which was first used in the 1971 disaster film Earthquake.
Okay, now I'll teach you noise-hounds how to fuck shit up, or shit fuck-ups.
Whistles can emit one of the most dangerous audible sounds, so the larger the worse. A regular whistle emits 1 watt of acoustic output (to compare, an everyday conversation emits 1 milliwatt). The Levavasseur whistle (Patent # US 2755767 A) is nothing more than a regular whistle attached to an acoustic cavity of 2' in diameter, along with a 1ft tube (looking much like a larger whistle), and, in tests, emitted 400 watts at a sound range of 2,600 Hz. One was created with a 4' diameter cavity and a 2' pipe, which emitted a hardly audible acoustic resonance of 1,000 watts at a range of only 37 Hz. Therefore, a whistle with a 16' cavity would emit the mind-numbing 7 Hz range.
Next is what is called the "Acoustic Gun," which is nothing more than an L-shaped tube of about 3' in length (on each angle) encased in 300 lbs of concrete. The way noise travels throughout the L shape, plus the encasing concrete making the sound vibrations bounce in the interior, causes a sound range of 190 Hz, and at 100 dB (very loud yelling in the mouthpiece) can cause painful internal vibrations in whomever it is pointed at.
Lastly is the "Acoustic Laser," which is nothing more than 49 tubes (all of equal length) attached in seven rows of seven tubes, with a spacing of 2" between each tube. At the mouthpiece, all the tubes are connected to one another in a single tube with flexible plastic tubing. This can be pointed at a group of people for a frequency of 0.6 Hz, causing organs to vibrate, and wild coughing.
Of course, you can test and try to invent your own, but I do caution against some of these experiments, as the creator of the Levavasseur whistle, Robert Levavasseur—according to documents from his colleague, Vladimir Gavreau (Science Journal Vol. 4, No. 1, 1968)—became an invalid upon the creation of one of the larger models.
Plus, being a fan of noise music, I could be out in the audience, and if you point that thing at me, I'll kick your nerdy ass—then rub all over your face what you made me do in my pants.