The relation between cochlear implant programming levels and speech perception performance in post-lingually deafened adults: a data-driven approach.

Purpose: Programming a cochlear implant (fitting) is an essential part of a user's post-implantation journey, defining how sound will be translated into electrical stimulation and aiming to provide optimal speech perception outcomes. Currently, there are no established, evidence-based guidelines for fitting cochlear implant users, leading to a high degree of variability in fitting practices, users' parameters, and probably outcomes. In this study a data-driven approach is used to retrospectively investigate the relation between cochlear implant fitting parameters and speech perception outcomes in post-lingually deafened adults.

Methods: 298 data points corresponding to fitting parameters and speech audiometry test results for the same number of adult, post-lingually deafened, experienced CI users were analyzed. Correlation analysis was performed, after which parameters from the top-scoring and bottom-scoring tertiles were compared via the Mann-Whitney-Wilcoxon u test.

Results: Weak correlations between dynamic range and speech audiometry outcomes were identified, having p values lower than (albeit close to) 0.05. A significant (p < 0.05) difference in electrical dynamic range (the difference between the minimum and maximum amount of current which may be delivered by each electrode) was found, with top-scoring subjects having on average a wider dynamic range.

Conclusion: The association between dynamic range and speech perception outcomes shown in this retrospective study highlights the need for deeper investigation into evidence-driven fitting. It might be a first step in the direction of evidence-based fitting, minimizing variability in outcomes for cochlear implant users and helping mitigate the issue of unexplained low performance.