Hearing outcomes following cochlear implantation with anatomic or default frequency mapping in postlingual deafness...

The aim of this study was to compare the outcomes of different mapping procedures based on anatomic or default frequency distribution in postlingual deafness adults who underwent cochlear implantation (CI).

Forty-eight adults with postlingual deafness who underwent CI (MED-EL) from January 2021 to May 2022 in our hospital were prospectively recruited. The participants were randomly assigned to two groups (the anatomic group and the default group). Postoperative computerized tomography (CT) scans were evaluated with Otoplan^® to determine the angular insertion depth (AID) and the specific locations of the intracochlear electrodes. Anatomic maps were imported into MAESTRO 9.0 software (MED-EL) for anatomy-based fitting for anatomic group, while default mapping program was set up for the default group. Hearing thresholds, Speech Recognition Scores (SRS), and subjects' auditory and musical abilities were evaluated 1 year after using the CI. Differences were determined in two groups using Stata statistical software, with significance defined as p < 0.05.

SRS under noisy conditions was significantly greater for anatomic group than the default group (p = 0.02). Under quiet conditions, however, mean hearing thresholds (0.5, 1, 2, and 4 kHz) and SRS did not differ significantly between the two groups (p = 0.07). Modified questionnaires showed that auditory (p = 0.02) and musical (p = 0.01) quality were significantly better following the anatomic mapping than the default procedure.

CI program based on the anatomic distribution may bring better SRS under noise conditions as well as better auditory and musical qualities than based on the default frequency distribution.