What Is The Worst Noise In The World?

Updated: Jul 31, 2018

From the sound of a knife on a bottle, via the frequency of fear and torture music, to the ancient Aztec death whistle - I go on a hunt for the very worst noise in the world.

Worst sound in the world
Photograph by Gabriel Matula

In 2012 a study by Wellcome Trust and Newcastle University found the most unpleasant sound for humans to listen to.

They reached their conclusion by using functional magnetic resonance imaging to watch 13 volunteer’s brains as they listened to 74 different sounds which could be encountered in daily life. The worst reaction - the sound of a knife of a bottle.

In fact, all of the top 5 worst noises were in the high frequency 2000Hz - 5000Hz range.

A range which seems to be particularly distressing for humans - maybe because it is the same frequency range as a human scream.

However I can’t help but feel a little disappointed that the most widely reported ‘worst sound’ in the world is something so simple, so benign, as a knife on a bottle. When it comes to our other senses, we are not let off so lightly. There are itches so intense they can drive you mad, tastes and smells so appalling that you will instantly vomit, and sights so horrifying they can never be forgotten. So it seems strange that when it comes to our hearing, there is little which apparently ranks above the irritating.

I just can’t believe that there isn’t a tune, a frequency, or a cacophony capable of more.

My quest for the worst noise in the world.

I am not the first person to try and discover the most horrible of sounds. In 2016, See Space Labs set up a "Worst Sound in the World" competition amongst their audience of sound engineers. The entries covered everything from sounds recorded around the house to discordant electronic tones - all were unpleasant, but as far as I am aware, none were truly horrific.

There have also been a number of other searches and studies. Results frequently cite the worst noise in the world as babies crying or someone vomiting. These two common contenders do more than just upset our ears, they tune into something much deeper and instinctual within us. We are evolutionarily preprogrammed to react to them physically. Yet when isolated as just a sound (and not actually accompanied by a distressed baby or person vomiting) their power is somewhat lost.

The frequencies of fear.

What does come out in much of the research and discussion on the topic, is that our reaction to sound is generally a deeply personal thing. What causes some to recoil, can be much more easily tolerated by others. In 2000 a new neurological condition was proposed called Misophonia. It sought to explain why certain people have highly negative feelings, thoughts and physical reactions to specific sounds. The condition is not widely understood, but it is thought that the brain of Misophonia sufferers misinterprets certain trigger sounds as dangerous. These trigger sounds are often repetitive, patterned-based sequences (a tapping pencil, repeated coughing) and incite all the usual stress reactions of fear.

Yet even without suffering Misophonia, there is a known sound which creates an involuntary sense of fear in everyone.

It is often called ‘The frequency of fear’ or ‘Ghost frequency’. Located at about 19Hz, this low hum sits just below the normal human hearing range and does something odd to the human body.

Those exposed to this super low frequency - also known as Infrasound - have been known to experience anxiety and sorrow, unexplained chills, and even apparitions. It was most clearly documented by Vic Tandy at Coventry University. His lab became the centre of a series of strange events most closely associated with a haunting. Those working there experienced a slowly increasing feeling of depression and unease with occasional sightings of ghost-like shapes at the edge of their vision. It continued for many days before, by coincidence, Vic brought his fencing sword to the lab for repair and noticed it vibrating in the clamp. While investigating the phenomenon he found a fan in the lab was vibrating at Infrasound. It was this frequency which was causing the widespread unease as well as vibrating the eyeballs at just the right rate to generate ghostly apparitions out of specks of dust. As soon as the fan was stopped, a sense of normality quickly returned.

Using sound as torture.

Yet when it comes to generating fear, the ‘ghost frequency’ is nothing compared to the way the US military have used sound as a form of prisoner torture. At Guantánamo Bay and other military detention centres, music has been routinely used to ‘break’ inmates. According to a torture playlist generated by Mother Jones popular torture tunes include heavy metal, pop, advertising jingles, and children’s theme tunes like Barney The Dinosaur and Sesame Street. These are played on repeat at extremely high volume between sessions of interrogation.

While the military have described this as “torture light”, it is anything but.

Clive Stafford Smith in the Guardian describes how relentless music torture mixed with sleep deprivation creates a mental state of futility and hopelessness.

He quotes prisoner Binyam Mohamed who has experienced both terrible physical torture (including razor blades sliced into his penis) and psychological torture through music.

“He could anticipate physical pain, he said, and know that it would eventually end. But the experience of slipping into madness as a result of torture by music was something quite different..."Imagine you are given a choice," he said. "Lose your sight or lose your mind." While having your eyes gouged out would be horrendous, there is little doubt which you would choose.”

We can all laugh at the idea of having to listen to the Meow Mix cat food jingle on repeat play. Now imagine it inescapable, at ear-splitting volume, for days on end, with absolutely no idea when it will stop. I have no doubt it would have the power to tear you from your sanity.

So what is my worst sound in the world?

So when you put all this research together what would constitute the worse sound in the world?

Well firstly, science suggests it would need to be at very high frequency (2000Hz - 5000Hz) or very low frequency (sub 20Hz). Secondly, it would need to be inescapably loud and repetitive. Thirdly, it would need to conjure up an inescapable feeling of futility. And finally, it would need to have a strong association with something instinctively fear-inducing.

The worst sound that I can find which fits this criteria - The Aztec Death Whistle.

This skull-shaped whistle was used by the ancient Aztecs - an ancient civilisation renowned for their bloody brutality. Just on its own, the high frequency scream emitted by the whistle is loud, continuous and innately terrifying. But now imagine hundreds of them playing together. That has to be one of the worst sounds imaginable.

And it’s still nothing compared to what this noise would have meant to someone during the time of the Aztecs. The whistles would be played on a war march to battle. The enemy would hear the continuous screams of the whistles coming ever closer, slowly becoming louder and louder and louder - the unavoidable sound of an impending horrifying death for yourself, and those around you.

Can you think of a contender for the worse noise in the world? Put your suggestions in the comments below.


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