Title

Central auditory function in children with permanent, bilateral, minimal-mild hearing loss

Date of Completion

January 2010

Keywords

Health Sciences, Audiology

Degree

Ph.D.

Abstract

Children with permanent, minimal-mild, bilateral hearing loss have been shown to exhibit a number of difficulties in language, academics, and social domains. Permanent hearing loss is a form of auditory deprivation, which can cause significant deviations of organization and function in the auditory areas of the brainstem and brain. A paucity of data exists documenting the effects of permanent mild levels of auditory deprivation on the central auditory nervous system (CANS). Temporary mild hearing loss in childhood has been shown to cause dysfunction in the processing of sound by the CANS. Given that temporary mild hearing loss can cause CANS dysfunction, auditory deprivation caused by bilateral mild permanent hearing loss in children may also lead to dysfunction of the CANS, resulting in disordered central processing of sound. This disordered sound processing, when coupled with reduced audibility due to the mild hearing loss, may be related to the academic, language, and social deficits experienced by this population. ^ This study utilized behavioral and electrophysiological measures to evaluate CANS function in ten children with previously diagnosed permanent, bilateral, minimal-mild hearing loss and ten age-matched, gender-matched normal hearing peers. A teacher questionnaire pertaining to school functioning was used to examine the relationship between central auditory function and school performance. ^ Results indicated that while no significant differences were present in mean scores between groups on behavioral and electrophysiological indices, significant differences did exist in the amount of children classified as 'disordered' using clinical criteria, normative data, and electrophysiological asymmetries. Additionally, children in the hearing loss group were rated significantly more poorly by their teachers in the areas of academics and communication, when compared to children in the normal hearing group. Teacher ratings of school function were strongly correlated to one measure of central auditory function, and this central auditory measure was also a significant predictor of teacher ratings in the areas of academics and communication. ^ Overall, children in this study with permanent, minimal-mild hearing loss did show signs of central auditory dysfunction on the tests utilized, and their central auditory abilities were related to how they performed and communicated in the classroom environment. ^