The relationship between electrical auditory brainstem responses and perceptual thresholds in Digisonic^® SP cochlear implant users

Abstract

Determining the electrical stimulation levels is often a difficult and time-consuming task because they are normally determined behaviorally – a particular challenge when dealing with pediatric patients. The evoked stapedius reflex threshold and the evoked compound action potential have already been shown to provide reasonable estimates of the C- and T-levels, although these estimates tend to overestimate the C- and T-levels. The aim of this study was to investigate whether the evoked auditory brainstem response (eABR) can also be used to reliably estimate a patient's C- and T-levels. The correlation between eABR detection thresholds and behaviorally measured perceptual thresholds was statistically significant (r = 0.71; P < 0.001). In addition, eABR Wave-V amplitude increased with increasing stimulation level for the three loudness levels tested. These results show that the eABR detection threshold can be used to estimate a patient's T-levels. In addition, Wave-V amplitude could provide a method for estimating C-levels in the future. The eABR objective measure may provide a useful cochlear implant fitting method – particularly for pediatric patients.

Keywords:

• Cochlear implant
• eABR electrical perceptual threshold
• T-level
• Loudness growth