Timing or Tuning: Outcomes After Anatomy-based Cochlear Implant Fitting

Introduction: Anatomy-based fitting (ABF) using Otoplan aims to reduce frequency place mismatch in cochlear implants (CI), but how timing and CI programming map deviations affect speech perception and quality of life remains unclear.

Methods: Med-El patients implanted between 8/1/2023 – 8/30/25 who underwent ABF had CI speech perception (CNC phoneme [CNCP], CNC words[CNCW], AzBio) (SPO), CI-Quality of Life (CIQOL), and map programming information collected retrospectively. Data was analyzed across timepoints of pre-CI, post-CI pre-ABF (ppABF), and post-ABF (pABF).

Results: Thirty-five CI patients (mean age: 64.3±13.8 years; 59% male) underwent ABF a median of 2.6 months post implantation. In paired ppABF versus pABF analyses, changes in SPO from baseline showed improvement (CNCP +3.8±22.3; CNCW+9.5±28.2; AzBio +12.7±16.7; paired n=6, p>0.05). Given significant difference in follow-up SPO time between groups (ppABF: 5.6 ± 3.7 months vs. pABF: 9.9 ± 6.0 months, p=0.03), time-adjusted analyses showed similar rates of improvement (CNCP 5.9 v 4.3 points/month; CNCW 3 v 3.1 points/month; AzBio 8.1 v 5.4 points/month).

Analyzing time from CI in 1–3, 3–6, 6–12, and >12 month intervals, pABF scores were numerically higher than ppABF across most speech measures (all p>0.10). CIQOL increased across timepoints (pre-CI 37.9±10.2; ppABF 41.6±7.9; pABF 47.8±13.4; intergroup comparisons p>0.05).

Examining central frequency alignment with Otoplan targets to pABF showed mean deviation decreasing from 1,279 Hz pp-ABF to 552 Hz pABF (57% improvement; p< 0.01; n=28), greatest in mid array electrodes (E3–E6). Stratifying by percentage change toward Otoplan (≥51.8% vs < 51.8%) showed no significant differences in pABF SPO (all p≥0.13); correlations between change and SPO trended negative but were non-significant (e.g., CNC r=−0.49, p=0.091; AzBio r=−0.45, p=0.125).

Conclusions: ABF was associated with greater SPO and CIQOL scores across time points, and improved frequency–place alignment, but greater alignment toward Otoplan did not correspond to superior outcomes, suggesting time and adaptation may influence functional benefit.