When sound waves enter the subways of the ear they follow what appears to be a long and arduous path. However, each of the “sub-stations” along this pathway (from #1 to #7) has a precise function:
- Sound waves are picked up the by the outer ear, consisting of the pinna and the ear canal.
- Sound is channeled along the ear canal all the way to the eardrum, which vibrates when the sound waves touch it.
- The vibrations of the ear drum are picked up by the three tiny bones (known as the hammer, anvil and stirrup) located in the middle ear creating a bridge from the eardrum to the inner ear.
- These vibrations move further on the pathway to the cochlea in the inner ear where they become sound waves. (The cochlea is a spiral-shapped capsule which houses a system of liquid filled tubes).
- When the sound waves reach the liquid filled tubes of the cochlea it begins to move in waves setting thousands of tiny nerve endings in motion.
- The vacillations of the hair cells are changed into electric impulses that travel along the auditory nerve, (the 8th nerve) with its final destination being the brain itself.
- The brain decodes the electronic impulses, transforming a stream of speech sounds (or sound vibrations) into separate, recognizable words.