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.
- Deafness, congenital
Loss of hearing present at birth. Congenital deafness contrasts to acquired deafness which occurs after birth. The distinction between congenital and acquired deafness specifies only the time that the deafness appears. It does not specify whether the cause of the deafness is genetic (inherited). Congenital deafness may or may not be genetic. For example, it […]
- Deafness-ichthyosis-keratitis syndrome
Deafness-ichthyosis-keratitis syndrome: See Keratitis-ichthyosis-deafness syndrome.
Death: 1. The end of life. The cessation of life. (These common definitions of death ultimately depend upon the definition of life, upon which there is no consensus.) 2. The permanent cessation of all vital bodily functions. (This definition depends upon the definition of “vital bodily functions.”) See: Vital bodily functions. 3. The common law […]
- Death rate
Death rate: The number of deaths in the population divided by the average population (or the population at midyear) is the crude death rate. In 1994, for example, the crude death rate per 1,000 population was 8.8 in the United States, 7.1 in Australia, etc. A death rate can also be tabulated according to age […]
- Death rate, infant
Death rate, infant: The number of children dying under a year of age divided by the number of live births that year. The infant death rate is also called the infant mortality rate. The infant mortality rate is an important measure of the well-being of infants, children, and pregnant women because it is associated with […]