For years there have been urban legends about a "brown sound" or "brown note," a frequency so low that it'll literally cause you to shit yourself. Not only has this elusive weapon been sought by governments, but it also crops up in science fiction. Just think about what this insidious weapon could do in the hands of an evil villain! It turns out the legend was born after several real-life tests of the Republic XF-84H "Thunderscreech" airplane in 1956, which earned the honor of being the loudest airplane ever built. Find out more about the poop plane and the quest for the sound of brown inside.
The problem with the Thunderscreech was that the supersonic propeller blades would cause rapid-fire shockwaves, even when the plane was sitting on the ground. Test pilots refused to take it up, and officials would order it to be towed far from the test center before firing up the engines, and only one of the two prototypes ever flew, logging only 10 hours. Why? Because those shockwaves would case nausea, spasms, seizures, and loosening of the bowels. What a ride. You can hear the otherworldy banshee wail of one here.
So the word spread that the soundwaves generated by the engines were causing the pooping, and like a game of telephone, soon folks began believing there was a secret low frequency that could unlock the human sphincter. NASA performed tests of low frequencies because they were worried their astronauts might start crapping out upon launch. They mounted cockpit seats on vibration tables that were blasted with 160 decibels in the range of 0.5 hertz to 40 hertz, but no one sounded off into the brown. Even more recently companies have built extremely massive subwoofers that have failed to make anyone prairie dog it, despite the massive amounts of low frequencies being pumped out.
Although this hasn't stopped it from seeping into poopular culture, probably most famously in Transmetropolitan, where Spider Jerusalem carries a Bowel Disruptor that operates on the brown note principle. It even has settings from "diarrhea" to "prolapse." Ouch. Although it was probably ripped off from Steve Meretzky's (of Infocom fame)The Superhero League of Hoboken computer game from 1994, Spider put it to a lot better use. In fact, Ben Folds used the brown note with Improv Everywhere in a 1996 concert hoax involving diapers and chocolate syrup. Now that's entertainment. Mythbusters even tackled the legend on an episode, and they recorded no poop at all.
So, until science comes up with a new method for causing uncontrollable evacuation, bowel disruptors will sadly remain science fiction and not fact. Which is a real pity, because we sure could have used one during the upcoming presidential elections. We'll have to just stick to vomit guns.