Abstract
Examination was made of the records of school-aged children with a bilateral sensorineural hearing loss who were seen for audiological assessment in the period 1984 to 1986. These records formed the basis of an investigation, reported in this paper, into the prevalence of progressive sensorineural hearing loss, the causes of hearing impairment in these children, the ages at which deterioriation occurs and the patterns of progression in terms of audiogram shape and symmetry. A figure of 9% was found for prevalence, but arguments are put forward to show that this is probably a minimum figure and that most studies are likely to under-estimate the number of children with progressive sensorineural hearing loss. There is a tendency for the deterioration to be greater in the better ear. The implications of this when assessing the role of hearing aids in causing deterioration is discussed.