Investigation of Maximum Monosyllabic Word Recognition as a Predictor of Speech Understanding with Cochlear Implant

Background: The cochlear implant (CI) is an established treatment option for patients with inadequate speech understanding and insufficient aided scores. Nevertheless, reliable predictive models and specific therapy goals regarding achievable speech understanding are still lacking. Method: In this retrospective study, 601 cases of CI fittings between 2005 and 2021 at the University Medical Center Freiburg were analyzed. We investigated the preoperative unaided maximum word recognition score (mWRS) as a minimum predictor for post-interventional scores at 65 dB SPL, WRS₆₅(CI). The WRS₆₅(CI) was compared with the preoperative-aided WRS, and a previously published prediction model for the WRS₆₅(CI) was reviewed. Furthermore, the effect of duration of hearing loss, duration of HA fitting, and etiology on WRS₆₅(CI) were investigated. Results: In 95.5% of the cases, a significant improvement in word recognition was observed after CI. WRS₆₅(CI) achieved or exceeded mWRS in 97% of cases. Etiology had a significant impact on WRS₆₅(CI). The predicted score was missed by more than 20 percentage points in 12.8% of cases. Discussion: Our results confirmed the minimum prediction via mWRS. A more precise prediction of the expected WRS₆₅(CI) is possible. The etiology of hearing loss should be considered in the indication and postoperative care to achieve optimal results.