This article originally appeared on VICE UK

I was at primary school in the 90s when my friend first told me about the "brown note", a specific note with a frequency so low that it makes anyone who hears it violently shit themselves.

The mystery of the brown note – the sound that's launched a million shits – has been bubbling under the surface of popular culture for decades. You might have heard about it via the South Park episode that devoted its entire 22 minutes to Cartman's discovery of a frequency "92 octaves below the lowest E flat" that causes instant diarrhoea. Or maybe it was on the Brainiac episode that investigated the "brown note", with inconclusive results? Or perhaps the MythBusters dedicated to the audio laxative?

More recently, a news story circulated about a DJ in Cornwall who played the brown note to a packed-out club, unleashing hell with a drop no one expected. It clearly wasn't true, but that didn't stop plenty of people from sharing it as if it was.

But the question remains: is the brown note a real thing, or just a load of shit?

"There haven't been any proper scientific tests on brown noise," says Dr Geoff Leventhall, an academic turned noise vibrations consultant who is so invested in low frequency sounds that he's conducted several of his experiments on himself.

"Some kid with a subwoofer might play it up high, but that's just people messing around," he says. "There have been tests on the effect of low frequency noise on people, and I've also done some looking at the effect on task performance and productivity, but the effects aren't very great."

He adds: "Scientifically there's something called white noise. There's also a pink noise and some people talk about a red noise, too. Beyond that, there's nothing that's really been accepted."

So where do the myths about the brown noise come from? The internet has helped rumours spread faster than ever before, and satirical articles are regularly shared as fact on Facebook, but Leventhall believes the idea of the brown noise first originated from a spoof article in New Scientist from over 40 years ago.

"It's the earliest reference to a sound causing diarrhoea that I've come across," he says. "I remember when I first saw the article after it was published in 1974; I didn't quite cotton on that it was a spoof. It's very subtle and quite convincing."

The article refers to the opening ceremony of the Great Exhibition in Victorian England, where thousands of people gathered. It claims that during the national anthem a horn let off the supposed "brown note", causing the crowd to immediately start wetting themselves and uncontrollably shitting everywhere. Reading like a 19th century slapstick comedy, it's not hard to see how it captured so many imaginations.

Here's what we know about the "brown note": it's supposedly in the infrasound area, somewhere below 20 hertz – which is beyond the lower limit of what the average human can detect. Within this infrasound region, the frequency of 7 hertz has always been shrouded in mystery because of supposedly harmful effects.

One day, back in the 1970s, Dr Leventhall read a French scientific paper that suggested subjecting yourself to this frequency could cause instant death. "I was so mad about this that I sat in my sound chamber to listen to 7 hertz myself," he says. "It was turned up to 145 decibels, which was a very high level and clearly audible. Nothing happened to me and I was still alive at the end of it."

It's probably worth noting that he didn't soil himself either, so consider that one strike against the brown note being a real thing.

"The idea that there is a frequency that your body may respond a bit more and a bit less to might be true," explains Dr Matthew Wright, a Senior Lecturer in Acoustics at the University of Southampton. "But the idea that there's a magical frequency where astounding things happen is wishful thinking. There's no particular reason why the bowels would respond differently than any other part of your body. With something as messy, wet and floppy as a human, how could something be as precise as brown noise?"

Dr Wright tells me that, among the scientific community, brown noise is considered to be an elaborate myth, based off the power of sound in other situations. He gives the example of a frequency being able to shatter a wine glass if it causes enough vibrations. "As you get to low frequencies," he says, "the amount of air movement you need in vibration is basically just the mechanical damage of getting blown backwards and forwards. If you make it strong enough, then yes, you can knock anything over, I suppose."

What he's saying is that while sound can be an extremely powerful thing and produce real physical effects, the brown note is most likely a big steaming pile of bullshit.

However, despite science coming out against the mysterious frequency, I had to know for sure. Armed with some speakers in close proximity to a toilet, I wanted to try out the brown note on myself.

There are dozens of YouTube videos claiming to be the real brown note, mostly with comments saying they don't work – but occasionally the odd positive response turns up among the "South Park brought me here" messages. Commenters in these instances claim the noise cured their constipation, or that the brown note caught them by surprise and really worked, but were these historically trustful anonymous YouTube trolls telling the truth?

Cycling through the videos, I sat on my sofa with the volume on full to see if they had any profound effect on my bowels. The noise was unsettling, similar to what I imagine being drunk inside an industrial wind turbine must sound like. I could feel the deep note moving down my spine and imagined it resonating through my stomach and down into my bowels.