You have to be pretty thick if you can hear anything, as you cannot embed sound into a gif!
Not sure if serious, but here goes...
You to be pretty thick to not read or understand the article... Your brain is expecting a sound on account of what you can see, so parts of your brain fill in the gaps as though there is a sound. You might as well call people thick for seeing optical illusions differently.
For my part, I "feel" the thud, but I don't "hear" anything.