[Congenital hearing disorders in children. 1: Acquired hearing disorders]

The results of international investigations on connatally acquired hearing loss are compared with the data of the German Registry on Childhood Hearing Loss (4058 cases). The connatal hearing disorders have shown a notable change in the last years regarding to aetiology and prevalence. In contrast to countries of the third world in developed nations the prevalence of permanent childhood hearing loss has been reduced down to 1 in 1.000 births. The results let assume a prevalence of approximately 1:1.200 births in Germany. For instance the number of rubella embryopathia decreased effectively. In contrast CMV infections and alcohol fetopathia are playing an increasing role. In the patients of the German Registry on Childhood Hearing Loss the percentage of certainly progressive hearing loss is 10.3 within the 4058 children with permanent hearing impairment. Diagnostic procedures first of all for the early diagnosis of CMV but also of toxoplasmosis are considerable because these infections may result in treatable hearing loss. Also consequent hearing tests are demanded in children with alcohol fetopathia.