Electrically Evoked Auditory Late Responses as a Novel Method for Cochlear Implant Programming

Abstract

Hypothesis: Electrically evoked auditory late responses (eALR) are useful as an objective cochlear implant (CI) fitting method. Background: Different objective and behavioral methods are used for CI fitting. However, there is no objective method that indicates that the electrical signal reaches the auditory cortex. eALR is an indicator that electrical signals reach the auditory cortex, so our aim was to investigate the use of eALR as an objective method for CI programming. Methods: Two different programs were created for 21 unilateral Med-El CI users. In the first program, the most comfortable level (MCL) was adjusted with the electrical stapes reflex threshold (eSRT), and the threshold levels (THR) were behaviorally adjusted according to the user's feedback. In the second program, the MCL level was adjusted to a level where all the components of the eALR were clearly seen, and the user did not feel uncomfortable; the THR levels were adjusted to the lowest level where the eALR P1 wave could be seen. The results of the MCL and THR levels of the two programs and the free field tests conducted with both programs were compared. Results: While MCL levels did not differ significantly between the two programs, a significant difference was observed between THR levels. In addition, no significant difference was found between hearing and speech tests with CI in the free field. Conclusion: The results revealed no significant performance difference between the two programs and that eALR could be preferred as an objective method for MCL determination.