Abstract Objectives: The degree of endolymphatic hydrops in Meniere’s disease may be related to hearing loss. However, the results of prior studies have been inconsistent. We aimed to investigate the relationship between endolymphatic hydrops and hearing loss characteristics in Meniere’s disease. Methods: This study included 54 patients (62 ears) with Meniere’s disease. Patients underwent three-dimensional real inversion recovery sequences for magnetic resonance imaging and puretone audiometry. Endolymphatic hydrops were assessed according to Gurkov’s criteria (2011). Correlations between different degrees of endolymphatic hydrops and pure-tone audiometry, as well as staging, were analysed. Results: Pure tone audiometry and staging were higher for vestibular endolymphatic hydrops complicated by cochlear ones than isolated cochlear or vestibular hydrops (both p<0.05). There was no significant correlation between vestibular endolymphatic hydrops and pure-tonal audiometry or staging (all p > 0.05). The degree of hydrops in the middle turn was correlated with the mid-frequency hearing threshold (p<0.05). The degree of cochlear hydrops was correlated with the audiometry, low-frequency hearing thresholds, mid-frequency hearing thresholds and staging (p<0.01). Conclusion: The types and sites of endolymphatic hydrops based on a 3D-real inversion recovery sequence can be used to indicate the degree of hearing loss in patients with Meniere's disease. Level of evidence: Level III.

Abstract Objectives To determine whether tinnitus negatively impacts the accuracy of sound source localization in participants with normal hearing. Methods Seventy-five participants with tinnitus and 74 without tinnitus were enrolled in this study. The accuracy of sound source discrimination on the horizontal plane was compared between the two participant groups. The test equipment consisted of 37 loudspeakers arranged in a 180° arc facing forward with 5° intervals between them. The stimuli were pure tones of 0.25, 0.5, 1, 2, 4, and 8 kHz at 50 dB SPL. The stimuli were divided into three groups: low frequency (LF: 0.25, 0.5, and 1 kHz), 2 kHz, and high frequency (HF: 4 and 8 kHz) stimuli. Results The Root Mean Square Error (RMSE) score of all the stimuli in the tinnitus group was significantly higher than that in the control group (13.45 ± 3.34 vs. 11.44 ± 2.56, p = 4.115, t < 0.001). The RMSE scores at LF, 2 kHz, and HF were significantly higher in the tinnitus group than those in the control group (LF: 11.66 ± 3.62 vs. 10.04 ± 3.13, t = 2.918, p = 0.004; 2 kHz: 16.63 ± 5.45 vs. 14.43 ± 4.52, t = 2.690, p = 0.008; HF: 13.42 ± 4.74 vs. 11.14 ± 3.68, t = 3.292, p = 0.001). Thus, the accuracy of sound source discrimination in participants with tinnitus was significantly worse than that in those without tinnitus, despite the stimuli frequency. There was no difference in the ability to localize the sound of the matched frequency and other frequencies (12.86 ± 6.29 vs. 13.87 ± 3.14, t = 1.204, p = 0.236). Additionally, there was no correlation observed between the loudness of tinnitus and RMSE scores (r = 0.096, p = 0.434), and the Tinnitus Handicap Inventory (THI) and RMSE scores (r = −0.056, p = 0.648). Conclusions Our present data suggest that tinnitus negatively impacted sound source localization accuracy, even when participants had normal hearing. The matched pitch and loudness and the impact of tinnitus on patients’ daily lives were not related to the sound source localization ability. Level of evidence 4.