title: [A clinical study of dip type hearing loss in children].
abstract: Between 1970 and 1994, 60 pediatric cases, with 81 ears found to have dip type sensory neural hearing loss based on the appearance of an audiogram, were reported to the Department of Otorhinolaryngology at Iwate Medical University. These findings were clinically evaluated and compared to adult findings. The following results were obtained; 1) The dip type hearing loss was commonly seen among boys. 2) Approximately 25% were due to acoustic trauma, while 75% were of unknown origin. 3) Out of the 81 ears, 74 (91.4%) had a 4 kHz dip. 4) An 8kHz drop indicated "abrupt type" hearing loss. 5) Many fathers of the children with dip type hearing loss were also found to have a hearing disorder. Among these fathers, many were found to have a dip type hearing loss similar to that of their children. 6) There were no differences in the clinical findings of dip type hearing loss between the adult and pediatric cases. Thus, the adult form is essentially equivalent to that in children. 7) Since dip type hearing losses were found mostly in the male group, it was assumed that a hereditary factor is involved.
authors.affiliation: Department of Otorhinolaryngology, Iwate Medical University School of Medicine, Morioka.
authors.forename: J
authors.initials: J
authors.lastname: Murakami
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001299:Audiometry; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006319:Hearing Loss, Sensorineural / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012737:Sex Factors