Acquired deafness: The loss of hearing that occurs or develops some time during a person's life but was not present at birth.

Acquired deafness contrasts to congenital deafness which is present at birth.

The distinction between acquired and congenital deafness specifies only the time that the deafness appears. It does not specify whether the cause of the deafness is genetic (inherited).

Acquired deafness may or may not be genetic. For example, it may be a manifestation of a delayed-onset form of genetic deafness. Or acquired deafness may be due to damage to the ear from noise.

Congenital deafness similarly may or may not be genetic. For example, it may be associated with a white forelock and be caused by a genetic disease called Waardenburg syndrome. Or congenital deafness may be due to something such as the rubella virus to which the mother was exposed during pregnancy.