Defining Clinically Meaningful Change in Speech Perception Following Cochlear Implantation: A Data-Driven Approach

While cochlear implantation (CI) studies have extensively characterized postoperative group-level speech perception outcomes, clinically-based speech perception criteria are required to assess individual changes in performance over time. This study aimed to characterize changes in speech perception following CI and to establish data‑driven benchmarks for clinically meaningful change (CMC) in speech perception. A retrospective analysis was conducted on 85 adult CI recipients (97 ears; mean age at implantation 51.5±18.1 years) implanted between 2012 and 2023. Most were female (65%), with unknown hearing loss (HL) etiology (59%) and post-lingual onset (64%). Aided speech perception was evaluated using speech reception thresholds (SRTs) and monosyllabic word and phoneme scores in quiet, with hearing aid pre-implantation and CI‑only post-implantation. Comparing pre- and post-implantation performance showed that, one-year post-implantation, SRT improved by 51dBHL, and monosyllabic word and phoneme scores by 40% and 46%, respectively. Poorer pre-implantation performance was associated with greater gains in word and phoneme scores. To define CMC, longitudinal speech perception scores were analyzed, and 95% confidence intervals for maximum change were calculated while accounting for the number of assessments. This analysis identified CMC thresholds of 19.1% for words and 14.1% for phonemes. Applying these thresholds indicated that in 8.6% of assessment intervals, both word and phoneme scores exhibited CMCs, with 62.5% showing improvement and 37.5% decline between two consecutive measurements. These data-driven benchmarks enhance the interpretation of longitudinal CI outcomes, support identification of meaningful individual change, and offer a practical framework for clinical decision-making and personalized rehabilitation interventions.