An investigation of incidence, etiology and diagnostic delay was performed in Oslo born children referred to the audiological department of Ullevål Hospital in the period 1989-91; hearing loss in these children required amplification and audiopedagogical training. An increase in incidence compared with 1975-84 was found. No child had a hearing loss caused by rubella. The age at time of diagnosis is increased, with a median age of 28 months. Children with moderate hearing losses are diagnosed at later ages. A considerable delay in the diagnosis of hearing-impaired children is shown.