How We Hear

Ear & Hearing

Your ear has three parts, each with a different purpose. The outer ear collects sound and funnels it to the middle ear. There the sound is amplified (made louder) and sent to the inner ear, where it is converted into nerve impulses (signals) that go to the brain. The brain compares the loudness of incoming signals from each ear to determine the direction of the sound.
  • External Ear - collects and concentrates sound energy.
  • Ear Canal - carries sound to the eardrum, a membrane separating the canal and the middle ear.
  • Eardrum - vibrates in response to changes in sound energy, setting into motion three tiny bones.
  • Middle Ear Bones - three tiny bones vibrate against the fluid-filled cochlea, transmitting the sound energy into the fluid.
  • Cochlea - inside the cochlea, special nerve cells pick up the sound waves in the fluid and generate nerve impulses.
  • Auditory (hearing) Nerve - carries nerve impulses from the cochlea to the brain, where they are received and heard as sound.