You are presented with the quiz "When a doorbell rings, what part of the body vibrates?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "adoorbell converts electrical energy into sound" and "when the sound waves hit the eardrum in the middle ear, the eardrum starts to vibrate". 

So, what's the best answer to the question?


 

       eardrum    