Loads of people can hear this gif even though it's silent
If you're ever looking to waste some time on the internet (which, let's be real, you almost certainly are), then venturing into the world of optical illusions is a great way to pass a few minutes. Or hours, actually, depending on how obsessed you become.
There's just something so fascinating about being able to trick your own brain into perceiving something that isn't there, and then confusing it even further when you find out exactly how the illusion is created. It really makes you realize the separation between the bits of your brain that are you, and the bits that are just there to process information.
In the same way, then, auditory hallucinations are equally fascinating. Much like optical illusions, they feed contradictory information to your brain, which then makes an attempt to process it - usually incorrectly.
Recently, one Twitter user decided to test out how many people were affected by a particular auditory illusion by posting a silent gif and asking how many people could actually hear a noise when watching it. Surprisingly, 70 per cent of respondents said that they did experience a sound, and only 18 per cent claimed to not hear anything.
The gif in question was made by Twitter user @IamHappyToast, who specializes in making funny and interesting clips. It was then posted by another user, who wanted to see how many others could hear a sound when watching it. Take a look for yourself, and try to work out what you hear (if anything) as you watch it:
The gif is actually nine years old, and has made its rounds on the internet before. However, with this new revelation that the majority of people actually perceive it as an auditory illusion, it raises questions about how the brain processes sound.
Dr. Lisa DeBruin, who shared the gif and posted the poll, said that her favorite theory about why the gif has this effect is because it "triggers the acoustic reflex, which is usually triggered by speech or loud noises." She's also keen on finding out which elements of the gif are most important in producing the illusion.
However, it turns out that there is a fairly simple explanation for why a thudding sound will be experienced by some people who watch the gif. It's called the McGurk effect, and it happens when a certain sound is paired with mismatching visuals. Through this effect, rather than perceiving a mismatched sound as incorrect, the brain changes what it hears to match the image in front of it.
Of course, this is taken one step further with the gif, as there is no accompanying sound. It seems that the brain, confused by a lack of sound, will implement one that it believes to be appropriate.
Happy Toast himself stepped in to explain that the thumping noise people hear is almost entirely created by the shake, and proved this by cropping out the majority of the image.
If you are one of the special ones who can hear it, congratulations - you just tricked your brain with a simple gif! And if you can't, don't worry - there's tons of other illusions out there for you to try.