Study in air-conducted and bone-conducted auditory brainstem responses in children with congenital external auditory canal atresia

Abstract

Objective To study the clinical value of air- and bone-conduction auditory brainstem responses(ABRs) in children with congenital aural atresia. Methods Air- and bone-conduction click-evoked ABRs in 38 children with congenital external auditory canal atresia were compared to those in 34 normal-hearing children. Results ABR threshold were (65.0±8.7) dBnHL for air conduction and (10.6±7.0) dBnHL for bone conduction in children with congenital external auditory canal atresia; and (25.6±1.7) dBnHL and (9.7±6.7) dBnHL respectively in normal hearing children.There was statistically difference between the two groups in air-conduction ABR threshold(t'=21.59, P 0.05). While the air-bone ABR threshold gap was greater in children with external auditory canal atresia than in normal hearing children(t'=13.78, P 0.05). Conclusion Bone conduction ABR is valuable in assessing function of cochlea, auditory nerve and brainstem in individuals with congenital external auditory canal atresia.It has important clinical value in objective differential diagnosis of conductive deafness with combined application of air- and bone-conduction ABRs. Key words: Ear, external; Congenital abnormalities; Auditory brainstem response