The human ear has three main parts - the outer, middle and inner
ear. The outer ear is like a funnel collecting sounds from the air. It leads to
a tube, the ear canal, which ends in a flexible, circular eardrum. Sounds make
the eardrum vibrate and this, in turn, makes three small bones in the middle
ear vibrate too. The bones pass the sound vibrations to the cochlea in the
inner ear, where they are changed into nerve signals that go to the brain. (World
of Science)