An auditory illusions, the human brain thinks that it can hear something that is either not “there” or exists in a very different form to how it is perceived.
Here's some of the cool illusions.
What do you hear? Brainstorm or Green Needle
Can you understand the garbled audio?
Another cool illusion.
This one is super cool, the illusion is overwhelming at first and I know you're gonna swear that you hear singing but you really don't hear anything.