ObjectiveThis study aimed to investigate the impact of middle ear effusion on the inner ear function in patients with otitis media with effusion (OME).MethodsClinical data from 39 patients with unilateral OME accompanied by elevated bone conduction thresholds (case group) and 50 OME patients without bone conduction changes (control group), who were admitted to Wuhu Hospital affiliated to East China Normal University between January 2022 and January 2024, were analyzed. Comparisons were made of hearing changes among the affected ears, healthy-side ears, and post-treatment affected ears (without tympanic effusion) in the case group, as well as the influence of relevant variables on bone conduction hearing before and after treatment in the affected ears.ResultsThe incidence of dizziness/vertigo was significantly higher in the case group than in the control group (P=0.002), and the time to first intervention was significantly delayed in the case group compared to the control group (P=0.008). High-frequency bone conduction hearing impairment was prominent in the case group. The bone conduction thresholds at 2 kHz and 4 kHz in the affected ears (34.1±13.27 dB, 29.49±15.04 dB) were significantly higher than those in the healthy-side ears (20.26±11 dB, 19.87±12.59 dB, P<0.001). After effusion resolution, the differences in bone conduction thresholds at 2 kHz and 4 kHz between the treated affected ears and the healthy-side ears remained statistically significant (P=0.003). Multiple linear regression analysis showed that mucoid effusion had a negative impact on hearing recovery at 2 kHz (β=0.39, P=0.009), while early intervention (β=-0.402, P=0.024) and absence of vertigo symptoms (β=-0.413, P=0.007) were protective factors for hearing recovery at 4 kHz.ConclusionMiddle ear effusion may adversely affect inner ear function, manifesting as dizziness/vertigo symptoms and irreversible high-frequency bone conduction hearing loss in some patients. Early intervention and identification of effusion type are of significant clinical importance for prognosis.