[Possibilities to diagnose hearing impairment in children].

Hearing impairment (HI) in children with a congenital or early onset is explained by genetic and environmental factors. Genetic factors are regarded as responsible for more than half of the cases of congenital HI and environmental factors are responsible for another 14-30%, but the etiology is still unknown in 20-40% [1]. Regarding the genetic causes, 30% are considered syndrome related, whereas 70% non-syndromic.