The tympanic membrane is a vital feature of the human ear, and is more commonly known as the eardrum. It is a thin, circular layer of tissue that marks the point between the middle ear and the external part of the ear. It is approximately 0.1mm thick, around a third of an inch in diameter, and has a mass of around 14mg. Despite this diminutive size and mass, the tympanic membrane is extremely tough and flexible, and difficult to damage beyond repair. The tympanic membrane is comprised of three layers of tissue: the outer cutaneous layer, the fibrous middle layer, and a layer of mucous membrane on the innermost surface. The membrane is held in place by a thick ring of cartilage. The tympanic membrane's function is to assist in human hearing. When sound waves enter the ear, they strike the tympanic membrane. The membrane vibrates with the force of the sound wave strike and transmits the vibrations further into bones of the inner ear. Patients with ruptured or missing tympanic membranes have extreme difficulty in hearing.
Written and medically reviewed by the Healthline Editorial Team
In Depth: Tympanic membrane