In the early stage of presbyacusis, patients often experience reduced speech perception in noisy environments despite normal audiometry, a condition known as ‘hidden hearing loss’. Diagnostic indicators like reduced amplitude of the ABR wave I, elevated hearing thresholds in the extended high-frequency range and decreased middle ear muscle reflex amplitudes aims to identify biomarkers for peripheral auditory pathology but remain inconsistent. Mismatch negativity (MMN) is a cortical auditory evoked potential generated when the brain detects sound changes. This study aimed to assess MMN as a diagnostic tool for hidden hearing loss in adults. Seventy-three subjects with normal hearing underwent an extended pure-tone audiogram examination ranging from 0.125 to 16 kHz and a subsequent MMN assessment with 2 different stimuli: two verbal (ba/da) and two non-verbal stimuli (1/2 kHz). The MMN’s amplitude and latency were measured and analyzed. A significant age-related effect on the MMN amplitude in the speech condition was found (χ² = 13.0, p = 0.002). Additionally, no further effects of age were observed on the cortical potentials examined. Also, no significant influence of EHT on the amplitude or latency of either the MMN or the P300 was detected in both the tone and speech paradigms. Thus, EHFT was used as an indirect biomarker to detect pathology, specifically cochlear synaptopathy, in the peripheral auditory system, but it is not suitable for detecting changes in the central auditory system. The amplitude of MMN, however, can be used to detect early pathological changes in the central auditory system.

Objectives: To investigate characteristics of health-related quality of life and evaluate the association between health-related quality of life (HRQoL) and hearing among different types of chronic middle ear diseases (CMED). Design: Prospective longitudinal cohort study. Setting: Tertiary referral centre. Participants: Adult patients undergoing surgical treatment for CMED. Main outcomes measures: Pure-tone audiometry, Zurich Chronic Middle Ear Inventory (ZCMEI-21). Results: A total of 108 patients (55 females, 53 males; mean age 51.0 years [SD 15.9]) were included. CMED included COM with cholesteatoma (epitympanic [n = 39]; pars tensa [n = 7]), persistent mastoid cavity (with recurrent cholesteatoma; n = 15; without recurrent cholesteatoma, n = 10), COM without cholesteatoma (n = 22), revision ossiculoplasty for hearing restoration (n = 14), and postinflammatory meatal fibrosis (n = 1). No significant differences between pre- and postoperative air conduction pure-tone average was observed in any type of CMED. Preoperatively, mean ZCMEI-21 score showed statistically significant differences among different types of CMED (p = 0.007) with persistent mastoid cavity without cholesteatoma exhibiting the highest mean ZCMEI-21 score (34.1, SD 7.7) indicating a poor HRQoL. At a mean follow-up period of 183 days, no statistically significant differences in ZCMEI-21 scores among different types of CMED were observed (p = 0.67). Conclusion: This study objectifies differences in HRQoL among different types of CMED. In types of CMED with indication for functional surgery only, such as persistent mastoid cavity without cholesteatoma or ossiculoplasty, the worst HRQoL was observed. Yet, in these types of CMED, HRQoL guides decision for treatment. Moreover, differences in HRQoL among different types of CMED are not closely associated with hearing, but largely depend on other symptoms, such as tinnitus, discharge or vertigo.