Short- Versus Long-Term Hearing Preservation and Speech Recognition Outcomes in Precurved and Straight Electrode Arrays.

Abstract

Objective: Compare audiologic outcomes between precurved and straight electrode arrays in cochlear implant (CI) recipients while controlling for age and preoperative hearing in a large cohort.

Study design: Retrospective chart review.

Setting: Tertiary referral center.

Methods: Adult CI recipients who underwent surgery from 2018 to 2025 with Cochlear Americas slim modiolar CI532/632 (precurved) or slim straight CI522/622 (straight) electrode arrays were included. Preimplantation and postimplantation low-frequency pure tone average (LFPTA) in the short- (1- and 6-months) and long-term (≥12 months) and speech recognition testing (CNC, AzBio in quiet) at 1-, 3-, 6-, and 12-months postactivation were recorded. Hearing preservation (LFPTA shift) and speech recognition scores were evaluated using multivariate linear regression analysis.

Results: One hundred seventy-two patients (190 ears) were included. 124 (65.3%) and 66 (34.7%) ears were implanted with a precurved or straight electrode, respectively. 47 (24.7%) ears had residual hearing (LFPTA ≤ 80) preoperatively. Precurved electrode recipients had significantly better hearing preservation compared to straight electrode recipients in the short-term (F = 4.016, P = .039), though this advantage diminished in long-term follow-up after controlling for age, sex, and preoperative LFPTA. CNC and AzBio scores were not significantly different between electrode arrays at any timepoint postimplantation.

Conclusion: Precurved electrodes were associated with small but statistically significant greater hearing preservation in the short-term compared to straight electrodes, but this difference did not persist in the long-term. Speech recognition outcomes were similar for precurved and straight electrodes at all timepoints. These findings should be considered during preoperative decision-making for potential CI recipients.