How we hear
Hearing begins when sound is collected by the pinna and enters the outer ear. It travels through the ear canal. This wax producing passageway is lined with tiny hairs and small glands.
Next, the sound waves enter the middle ear, where the sound strikes the eardrum, which vibrates. Behind the eardrum are three tiny bones called the malleus, incus and stapes (also known as the hammer, anvil and stirrup). These bones transmit vibrations into the inner ear.
The main part of the inner ear is called the cochlea. The cochlea has about 25,000 to 30,0000 tiny nerve endings which convert sound waves into nerve impulses. The auditory nerve sends the impulses to the brain where they are interpreted as sound.