Mind & Body

Why Can You "Hear" This Silent Animated GIF?

Even though it's silent, a majority of people "hear" something in this gif. Do you?

Crossing Wires

According to a Twitter poll posted by University of Glasgow researcher Lisa DeBruine, around 70 percent of people hear a "thudding" sound every time the small pylon lands. This isn't the first time this image has made people hear things — ever since Twitter user HappyToast created it in 2008, people have periodically marveled at the weird auditory illusion. So what exactly is going on?

In short, your senses are working as they should. In the same way you understand what certain words mean in the context of a sentence, your individual senses understand the world in the context of your other senses. The phenomenon where one sense influences what another sense perceives is called cross-modal perception, and it pops up everywhere: scientists can adjust the sound of a chip's crunch to make it taste fresher, advertisers can lower the pitch of a commercial to make the product appear larger, and when an editing trick layers the sound of a man saying "fa" with footage of him saying "ba," you hear "ba" every time. Try this online exercise to see what a difference a sound can make in what you see.

Something Out of Nothing

Of course, this is tweaking sensory input that's already there. You're actually tasting the chip and actually seeing the man speak, but this gif is completely silent. Surely it's not possible for your eyes to make you hear something that isn't there at all! In fact, it is. A March 2017 study found that 22 percent of people heard faint sounds that weren't there when researchers flashed light in their eyes, creating what the researchers called visually evoked auditory response, or V-EAR.

People talk a lot about synesthesia, the condition where information received by one sense is perceived by another (seeing sounds or hearing flavors, for instance). But this gif shows that you don't have to have a rare gift for your senses to cross paths. Evolution made your senses great at predicting the world around you. It's just that sometimes, those predictions aren't quite right.

The McGurk Effect

Written by Ashley Hamer December 5, 2017