Do different types of cochlear implant electrode influence hearing preservation and speech perception?

Background: Hearing can be preserved in patients with considerable low-frequency hearing implanted with cochlear implants. However, the most favorable electrode type for hearing preservation and speech perception has been debated.

Objective: The aim was to evaluate hearing preservation and speech discrimination one year post-implantation for all types of cochlear implant electrode used for adult patients implanted between 2014 and 2022.

Methods: The HEARING group formula was used to calculate the degree of hearing preservation, which was defined as minimal (0-25%), partial (25-75%) or complete (≥ 75%). Speech perception was measured by monosyllabic words.

Results: Analysis of hearing preservation for the various electrode types revealed that FLEX 24 preserved hearing statistically significantly better (p < 0.05) than FLEX 28, FLEX soft, and contour advance. Also, FLEX 20 preserved hearing statistically significantly better (p < 0.05) than contour advance. No statistically significant difference was found for the monosyllabic word score for the different electrode types.

Discussion: There was a statistically significant difference between the electrode types in terms of hearing preservation but not for speech perception. The result of this study contributes important information about hearing preservation and speech perception that can be used for pre-surgery patient counselling.