This phenomenon occurs when audio from one sound is paired with the visuals of another sound and we hear a different result entirely.
In other words, what we see can change what we hear.
For example, in this BBC Horizon clip audio of a man saying 'baa' paired with a video of him saying 'faa' - this leads us to hear 'faa' instead.
However, the animation of the skipping pylons takes this phenomenon a step further; there is no sound in the gif, but the visual stimulus is still enough for people to hear a corresponding sound.
This effect is also seen in a study where 22 per cent of participants 'heard' faint sounds when shown a flash of light.
Surprisingly, all of this suggests that more people can 'hear movement' than the estimated 5 per cent of the population with synesthesia; a condition where one sense (for example, sound) is perceived as one or more other senses (for example, sight).