Question: how do we hear things

Ceri-Wyn Thomas answered on 24 Jun 2010:

What we hear as sound is in fact very fast vibrations of air molecules. It is your vocal chords that start these vibrations when you talk, and the vibrations travel out to other people’s ears. Inside your ear (down the tube you can feel) there is what is called an ‘eardrum’, a thin sheet of skin-like material that responds to the vibrations of the air. These vibrations are transferred from the eardrum to 3 small bones in the middle part of your ear, which in turn pass on the vibrations to the inner partof your ear, the cochlea. The cochlea is filled with liquid which flows as a result of the motions of the bones in the middle ear, and nerve endings pick up the motions of this liquid and pass these signals on to the brain, which turns these messages into the ‘sound’ you hear.

It’s a very sensitive system, and a friend of mine once burst an eardrum when a football hit him hard on
the side of the head. It took weeks for the eardrum to heal and he was deaf in that ear until it had. It was also very painful apparently. Eek!