Congenital hearing loss: diagnostic and management in otological aspects.

What is the prevalence of congenital hearing loss? The prevalence of congenital bilateral permanent hearing loss is approximately 1 to 3 (2 to 4) in 1,000 live births per annum. The prevalence increases if the congenital unilateral permanent hearing loss is included. Developing countries have a tendency for higher prevalence. The prevalence is 10 to 20 times greater in neonates at risk than in the general neonatal population. However, about 50% of all congenital hearing impaired children have no risk. Congenital hearing loss is also more prevalent than metabolic disorders such as congenital hypothyroidism (1 in 4,000), or phenylketonuria (PKU) (1 in 15,000) which are usually checked for in newborn screening programs in many countries.