Hearing investigations of school children in North Trøndelag County.
D000293:Adolescent; D001299:Audiometry / Q000266:history; D002648:Child; D002675:Child, Preschool; D004427:Ear Diseases / Q000209:etiology; D005260:Female; D005387:Finland; D006311:Hearing Disorders / Q000175:diagnosis* / Q000209:etiology; D006320:Hearing Tests; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D008297:Male; D012537:Scandinavian and Nordic Countries; D012572:School Health Services