Hearing and audiometric estimates in a blind population in North-Western, Nigeria

Abstract

Background: In our environment there is lack of awareness about the specific effects that hearing loss has on a blind person. The early identification of deafness and its early treatment have clearly been shown to lead to significant improvements in a child's social and educational achievement. There is also evidence that comprehensive examination of students in boarding schools usually leads to rapid identification of conditions predisposing or associated with preventable ear diseases. Objective: This study aims to estimate prevalence of hearing impairment and other otological problems among blind students in Kaduna State special education school. Subjects and Methods: All consenting, consecutive students were recruited and assessed using the WHO Ear and Hearing disorders survey protocol. Otoscopy and audiometric air conduction thresholds were established separately for the left and right ear of each subject respectively, using frequencies of 500, 1000, 2000, and 4000Hz to estimate mean hearing thresholds. Results: A total of 58 students were recruited for this study with a prevalence of hearing impairment of 17.2%. The age of the students ranged from 10 to 25years with a mean age of 15.53years (SD: 3.3years). There were 22 (37.9%) females. Pure Tone Audiometry for the right ear revealed a minimum hearing threshold of 15dBHL and maximum of 83.75dBHL, with a mean hearing threshold of 22.03dBHL (SD: 1.20). Similarly, the left ear had a minimum threshold of 12.50dB and a maximum of 28.75dBHL, with a mean of 20.50dBHL (SD: 0.40). Five students (8.6%) had unilateral hearing impairment of variable severity. Cerumen auris (wax) was the commonest 18 (31%) otologic disorder. Conclusion: Efforts are needed toward strengthening hearing screening with provision of hearing aids for the institutionalized blind or persons with dual disabilities.