The outer ear is the gateway to the ear canal and middle ear. The hole in the middle of your ear is called the pinna,or auricle. The pinna is shaped like a funnel to collect sound waves and sends them down to the ear canal. As the sound travels down the ear canal,it reaches the eardrum. The eardrum is a circle of tightly stretched skin which makes the sound into vibrations and vibrates the sound into the ossicles. Ossicles are the 3 tiny bones behind the eardrum. The ossicles are called the hammer (malleus), the anvil (incus), and the stirrup (stapes).
The ossicles send the sound vibrations to the cochlea,which is a snail shaped spiral. The cochlea has micro hairs that send the vibrations to other little hairs and out as electrical signals to the auditory nerve, which then sends the signals to the brain so it can be recognised. There are also some canals on the top of the cochlea,which are called semicircular canals,because of their shape. These canals sense when you're about to fall,and send signals to the brain so the brain can tell your other parts to stop. Basically it helps you balance.
I think the ear is the most amazing system in the body. After all,we wouldn't be able to hear without our ears!