Steady state evoked potentials: an objective measure of residual hearing in young cochlear implant candidates [Abstract]

Abstract

Precise determination of hearing thresholds in prospective cochlear implant candidates is essential. As the minimum age of implantation for youl1g children has been reduced, the use of objective measures of hearing has become an important part of their pre-operative evaluation. Steady-state evoked potentials are scalp potentials elicited in response to sinusoidally amplitude and/or frequency modulated tones. A system has been developed at The University of Melbourne which allows the presence: of such a response to be detected automatically thus permitting an objective. frequency specific estimate of hearing to be made in sleeping or awake subjects. This paper investigates the use of SSEPs in determining hearing thresholds in young profoundly deaf children. Responses in such patients are compared with those: obtained in neonates, and a group of sleeping adult subjects with varying degrees of sensori-neural hearing loss. Results indicate that the SSE? procedure is well suited as a measure assessing residual hearing in profoundly deaf children suitable for a cochlear implant in that it can provide an accurate estimate of auditory thresholds using frequency specific stimuli presented at high levels.