Genetic Aspects of Hearing Impairments in Children

Abstract

An analysis of the results of hearing measurements on a year class of 14-year-olds at Stockholm schools comprising 10,778 children has been made. The hearing tests were performed as screening audiometry at a hearing level of 20 dB (ISO) in the frequency range 250–8000 Hz. 317 of the pupils (2.9%) who did not pass the screening tests were referred to a thorough hearing examination. The majority of the hearing impairments belonged to the sensory-neural type. The boys were affected twice as often as the girls. In the subgroup comprising the impairments in the high frequency range the boys showed a 3 times greater incidence than the girls. These defects have hereto been considered to be of exogenous origin. The authors instead are of the ophion that they are of endogenous nature and discuss this hypothesis in detail.