Related Experiment Video
Updated: Jun 1, 2025

Author Spotlight: Advancements in Impedance Monitoring for Cochlear Implant Surgery
Published on: August 4, 2023
Intraoperative impedance and ECAP results in cochlear implant recipients with inner ear malformations and normal
Merve İkiz Bozsoy1, Aysun Parlak Kocabay2, Betül Koska2,3
1Department of Speech and Language Therapy, Anadolu University, Eskisehir, Turkey.
Background:
The intraoperative measurements are essential steps in cochlear implant (CI) surgery for confirming correct electrode placement.
Objectives:
To examine the intraoperative impedance and electrically evoked action potential (ECAP) measurement results of cochlear implant (CI) users with normal cochlear anatomy (NCA) and to compare them with CI users with inner ear malformations (IEM).
Material And Methods:
This retrospective study included intraoperative data of 300 ears from 258 individuals using Medel® and Cochlear (Nucleus®) CI devices.
Results:
Impedance values differed through all regions, and that differences in ECAPs results mainly stemmed from the basal region in Cochlear users, when comparing the impedance values and ECAPs recording prevalence between the NCA and IEM groups, it was observed that there was no significant difference in the impedance values across the intracochlear regions of the groups (apical; p = .26, middle; p = .12, basal; p = .99). However, it was found that the prevalence of measurable ECAPs in all intracochlear regions of the NCA group was higher than the IEM group (p = .000).
Conclusion And Significance:
The robustness of cochlear structures is a crucial factor in the recording of ECAPs. Furthermore, findings in the IEM group demonstrated that proper placement of intracochlear electrodes did not guarantee effective auditory nerve stimulation.

