Over the past twenty years hearing impairment has become widely recognized as one of the most important problems in the children with Down's syndrome. We have continued longitudinal observations of the hearing and speech development of children with Down's syndrome during the 10-year period from 1982 to 1991. One hundred ten children with Down's syndrome were examined and followed in the Department of Otolaryngology, Teikyo University Hospital. The examinations included otomicroscopy, behavioral audiometry, auditory brain stem response audiometry and tympanometry. Questionnaires were also administered to obtain information on the speech and hearing development of the children.
In the present paper, we discuss assessment of hearing evaluation and the characteristics (degree, incidence, and types) of hearing impairment in Down's children. We divided the children into the following groups according to hearing acuities: 35 children with a normal hearing level (0-39dB), 54 children with a moderately impaired hearing level (40-79dB) and 21 children with a hearing level above 80dB, and in 12 of these 21 children the finding was unilateral, and the 9 remaining children was bilateral.
Thus the incidence of hearing impairment with a threshold higher than 40dB was 68%. We detected otitis media with effusion (OME) in 34 (63%) of the 54 children with moderate hearing loss. Active treatment with medication or minor surgery, such as myringotomy or insertion of a ventilation tube, resulted in remarkable improvement in hearing in 26 children with OME. We used hearing aids for patients with prolonged otitis media and those with a hearing loss greater than 50dB in both ears. When their hearing acuity improved in response to appropriate medical care and the use of hearing aids, human-relations improved and speech development accelerated.
We emphasize that appropriate medical care and management of hearing impairment, including the use of hearing aids, were required for both patients' emotional and linguistic development.
