Medical Term Definition

Eardrum

The eardrum, also called the tympanic membrane, is a thin, flexible membrane that separates the external auditory canal from the middle ear. It plays an essential role in hearing by vibrating in response to sound waves that reach it.

When sound enters the ear canal, the resulting changes in air pressure cause the eardrum to vibrate. These vibrations are transmitted to the three tiny bones, called ossicles, in the middle ear. The ossicles then transfer the vibrations toward the inner ear, where they contribute to the process of hearing.

The eardrum also acts as a protective barrier between the external auditory canal and the middle ear. However, it can be damaged by infections, injuries, sudden pressure changes, or the insertion of objects into the ear.

QUICK FACT

  • A hole or tear in the eardrum is called a perforated eardrum.
  • A perforation may cause pain, discharge, or hearing loss, although some small perforations heal naturally.
  • The eardrum is important for normal air conduction because it transfers sound vibrations to the middle-ear ossicles.

COMMONLY CONFUSED WITH

  • Ossicles: Three small bones in the middle ear that receive vibrations from the eardrum and transmit them toward the inner ear.
  • External auditory canal: The passage through which sound travels from the outside environment to the eardrum.
  • Middle ear: The air-filled space behind the eardrum that contains the ossicles.

SEE ALSO