Watch the first clip. Do you hear any noise?

Then watch the second one. Do you hear anything?

(Explanation below second clip.)

 

Lots of people hear a thud in the second video. How is this possible when it's actually silent? IFLScience.com explains that "our perception of sound can be influenced by visual information..."  The BBC explains why most people have to see the ground shaking in order to hear the sound. The phenomenon is called vEAR, or visually evoked auditory response.