The ear consists of the outer, middle, and inner ear. It
plays a role in hearing, balance, and spatial orientation.
The outer ear collects sound. It includes the auricle, the
auditory canal, and the external surface of the eardrum, which is a membrane
separating the outer and middle ear.
The middle ear is the cavity behind the eardrum. In response
to sound waves, the eardrum vibrates. The vibration is passed on to small bones
(hammer, anvil, and stirrup) that amplify and transmit the vibrations to the
inner ear.
The inner ear includes the vestibule and the cochlea. The
vestibule is the organ that contributes to balance and spatial
orientation. The cochlea is the hearing organ. It contains
specialised sensory cells called hair
cells. When the “hairs” are moved as a result of sound vibrations, these cells
translate this mechanical stimulation into an electrical signal that is carried
to the brain by the auditory nerve.
Source: GreenFacts, based on the National Institute for Health
Glossary
