:Hearing mechanism:

The process of hearing is a series of transformations of energy. Acoustic energy, that is air pressure variation, enters the outer ear canal (1. in the diagram below). This causes vibration of the eardrum (2). This mechanical energy is transmitted by the bones of the middle ear (4,5,6) to the oval window in the cochlea (8). Inside the cochlea the vibrations are converted to nerve impulses, which are transmitted to the brain via the auditory nerve.

  1. Outer ear canal (meatus)
  2. Eardrum (tympanum)
  3. Middle ear
  4. Hammer (malleus)
  5. Anvil (incus)
  6. Stirrup (stapes)
  7. Eustachian tube
  8. Cochlea