Cortical Auditory Evoked Potentials in Assessing Benefit from Cochlear Implants, Hearing Aids and Bimodal Stimulation

Abstract

Context: Aided Cortical Auditory Evoked Potentials (CAEPs) can be one of the objective methods to assess benefit from hearing devices in difficult-to-test population. There is a dearth of studies using CAEPs to evaluate the benefit obtained with bimodal stimulation. Aim: The aim of the present investigation was to investigate if CAEPs can be used as an objective measure to assess benefit from bimodal stimulation. Participants and Methods: CAEPs using /t/ stimmulus was recorded from 6 children in 3 conditions (using only hearing aid, with only cochlear implant [CI] and using bimodal condition). Behavioral tests carried out included aided sound field thresholds and Early Speech Perception Test (ESP) in auditory mode. Results: CI assisted thresholds for all the six children were within speech spectrum whereas hearing aid assisted thresholds were within speech spectrum for three children and outside speech spectrum for three. The results of ESP complimented the aided thresholds. Amplitude of CAEPs appeared to show an association with behavioural measures. The amplitude of CAEPs were lesser when the benefit from hearing device was lesser. Conclusion: The results of the present study indicate that CAEPs can be used to evaluate benefit/advantage from bimodal stimulation in difficult-to-test population. This case report series provides empirical evidence for use of CAEPs in clinics. Studies on larger population are needed to confirm the results of the present study.