The extremely bizarre animated GIF is an audio illusion which shows a large electrical pylon jumping rope, yet even though the animation is completely silent, every time the pylon hits the ground in the animation, many people can almost swear they hear a ‘thud’.
University of Glasgow psychologist Dr Lisa DeBruine posted the animation on twitter and surveyed around 14000 people asking whether they could hear something, and over 75% of the participants to perceive some sort of sound.
The reason for this according to Dr Bruine is that the ear has an acoustic reflex, which is a defensive reaction that is designed to protect your hearing by anticipating when a very loud sound is about to occur.
