GIFs don't have sound, but a massive amount of people claim they hear something when they watch a certain GIF. 

It's a clip of two high-voltage wire towers using their power lines as jump ropes while another wire tower hops over the cables. 

It's a cute, silent GIF, but what is crazy is the sound that's seemingly made when the jumping tower hits the ground:

Did you hear it? If so, you aren't alone. In one study, 70 percent of participants admitted to hearing a thudding sound as the tower hit the ground. 

So what causes it? One possible explanation is the McGurk Effect, when what we see affects what we hear. Check this out:

Another cause might be synesthesia, where one sense is perceived by another, so we "hear" the sight of the tower hitting the ground.

Whatever it is, it just shows how strange the human brain can be. 

Photo Credit: Getty