It occurs to me that there are people who weren’t on this website in 2012 and therefore never saw the magical gif that you can actually hear:

It’s been over five years and that still impresses the hell out of me.

wdym you can hear it?

Basically, it’s a form of synesthesia, movement-hearing. In this case, you expect to hear a thud, so you do. It’s estimated that 20% of people experience this type of synesthesia, as opposed to 2-4% for other kinds.

YO what the FUXK

The longer you watch it the more you get convinced that you can hear a  distant thud and the air displace.