Background/Objectives: Frequency-to-place mismatch between cochlear implant (CI) electrodes and cochlear tonotopy has been suggested to affect postoperative speech perception. This study aimed to examine the associations between frequency-to-place mismatch and speech perception outcomes across multiple linguistic levels in patients with CI and to assess how these associations change over time using postoperative computed tomography. Methods: This retrospective cohort study included 44 postlingually deafened adults who underwent unilateral cochlear implantation with a Flex28 electrode by a single surgeon at a tertiary care hospital. Speech perception was assessed using CI-2004, a Japanese speech perception test consisting of monosyllables, consonants, words, and sentences, in quiet settings at 3, 6, and 12 months after CI activation. Partial correlation analyses between frequency-to-place mismatch and postoperative speech perception scores were performed in 35 of the 44 patients, controlling for age and mean preoperative pure-tone thresholds. Results: Negative associations were observed between frequency-to-place mismatch and CI-2004 scores, particularly for monosyllable and consonant perception in uncorrected analyses. After correction for multiple comparisons, only consonant perception at 3 months after CI activation remained significant (r = −0.52, p = 0.002). Similar patterns were observed for other speech measures and at later time points, although these did not remain significant after correction. Conclusions: Frequency-to-place mismatch was associated with postoperative speech perception outcomes, particularly those involving phoneme-level recognition. After correction for multiple comparisons, only consonant perception at 3 months after CI activation remained significant.

Objectives: The middle cranial fossa (MCF) approach is valued for preserving hearing while accessing the internal auditory canal (IAC), petrous apex, inner ear, and related structures. This study evaluated its clinical outcomes across otolaryngological diseases, focusing on postoperative complications, hearing preservation, and the effect of IAC manipulation on auditory function. Methods: We retrospectively analyzed 35 patients who underwent MCF otologic surgery at a single center over twelve years. We calculated the proportion of MCF cases among all otologic surgeries and assessed postoperative complications and hearing changes (bone conduction thresholds). Outcomes were compared between patients with and without IAC manipulation. Results: MCF procedures comprised 1.4% of all otologic surgeries. Petrous bone cholesteatoma was the leading indication (15 cases). Intracranial complications occurred in 4 patients (11.4%): seizures, epidural abscess, and cerebral infarction. Facial nerve paralysis occurred in 3 (10.7%) patients without any cerebrospinal fluid leaks. In patients without IAC manipulation, hearing functions were preserved (22.3 ± 7.8 dB HL pre- vs. 25.7 ± 9.5 dB HL postoperatively), whereas those with IAC manipulation showed significantly greater deterioration. Conclusions: The middle cranial fossa approach, though technically demanding and infrequently used, offers a safe and effective option across various otolaryngological diseases. This approach achieved favorable hearing preservation with a low complication rate, particularly when intradural manipulation of the IAC was not required.