The ear is divided into three regions: the outer ear, middle ear and inner ear.
When sound waves enter the ear canal, they cause the eardrum to vibrate. The vibration moves the three bones in the middle ear, called the ossicles. The ossicles are also known as the hammer (malleus), anvil (incus), and stirrup (stapes). These tiny bones transfer and amplify sound waves to the oval window, which is located behind the stirrup.
When the oval window vibrates, it moves fluid across a membrane inside the cochlea. The fluid causes the membrane to move. Specialized hair cells translate this movement into nerve impulses, which are sent to the brain through the vestibulocochlear nerve. The brain interprets the impulses as sound.Unsupported extension