Introduction

The electrically evoked compound action potential (ECAP) represents a synchronized response generated by a group of electrically activated auditory nerve fiber.

ECAP measures are advantageous because they can be measured using clinically available software, and can be used as an indirect estimate of spiral ganglion neuron (SGN) density in a subject, and then compared to speech recognition measures obtained within the same period of time during the life of the subject.

In general, ECAP recordings provide information about the integrity of the electrode-nerve interaction. Studies show that for a constant inter phase gab (IPG) the slopes of AGFs are correlated with the number of surviving auditory neuron, generally speaking, steeper slopes are positively correlated with higher neural survival. ECAP thresholds can be used as rough estimates for initial loudness differences between electrodes during the first fitting, and improvement of ECAP thresholds after surgery show better synchronization in the auditory nerve.

Aim of the work:

The aim of this study was to determine the extent to which the slope of electrically evoked compound action potential amplitude growth function is correlated with speech perception performance in cochlear implant user .The final aim was to investigate whether the slope of the amplitude growth function of the ECAP can be used as a prognostic factor for good performance with CI.