There’s a gif currently going viral on Twitter that some people claim they can “hear”, despite it being totally silent.
OK, so first things first. Can you hear his gif?
Does anyone in visual perception know why you can hear this gif? pic.twitter.com/mcT22Lzfkp
— Lisa DeBruine ?️? (@lisadebruine) December 2, 2017
Some people seem to think that the sound may have something to do with our heartbeats and that this is what is actually being heard.
Lisa DeBruine, the scientist who posted the gif, doesn’t think so.
For the dozens of people who've suggested it's just your heartbeat:
Typical adult resting heartrate is 60-100 bmp. This gif is about 50bmp, so I wouldn't expect so many people to experience it if it required synchronisation with your heartbeat.
— Lisa DeBruine ?️? (@lisadebruine) December 4, 2017
She says her favourite explanation has to do with the “acoustic reflex” which is an involuntary muscle contraction that takes place in the middle ear.
My favourite explanation so far is that this triggers the acoustic reflex, which is usually triggered by speech or loud noises. https://t.co/OjHX84xs4C
— Lisa DeBruine ?️? (@lisadebruine) December 3, 2017
The Verge spoke to Christopher Fassnidge, a doctoral candidate in psychology who thinks that the illusion may be caused by synesthesia.
The word synesthesia comes from two Greek words, syn (together) and aisthesis (perception), which is an apt description of the condition.
People with synesthesia simultaneously perceive one sense with another. For example, they may look at a sunset and taste strawberries or hear a piano note and see the colour blue.
Since synesthesia is tricky to diagnose (and often goes undiagnosed entirely), we don’t have exact figures on how many people have the condition – but research suggests it’s between in 1 in 300 and 1 in 2000 people.
Throughout history, many famous artists and musicans have been self-described synesthetes. Writer Vladamir Nabokov heard certain letters as colours, musician Duke Ellington heard muscial notes as colours, as did painter Wassily Kandinksy.
“That’s the power of the mind,” Pharrell Williams told NPR .
“People with synesthesia, we don’t really notice until someone brings it up and then someone else says, ‘Well, no, I don’t see colours when I hear music,’ and that’s when you realise something’s different.”
Pharrell added that he sees his synesthesia as an asset when creating art and that many great artists have synesthesia.
100 ago, researchers said that synesthesia was a result of “crossed wires” in the brain; but today, neuroscientists take a more complex approach to understanding brain function.
It is now being posited by University of Cambridge professor Simon Baron-Cohen that synesthesia results from a genetically driven overabundance of neural connections in the brain.
Baron-Cohen and his colleagues believe that synesthetes’ brains have more connections between neurons.
He says we all have these extra connections as infants but they get naturally “pruned” as we grow. Synesthetes keep these connections longer than others.
In Baron-Cohen’s research, synesthesia is more common than other estimates: his work indicates that it occurs in roughly seven per cent of the population.
Fassnidge believes that the type of synesthesia taking place in the “noisy gif” may be even more common, affecting up to 20 per cent of people. He calls it a visually-evoked auditory response, or vEAR for short.
For more similar gifs, pop over to the r/noisygifs subreddit (yes, there is a subreddit for everything).