[Preliminary analysis of the factors affecting sound localization in patients with unilateral sudden sensorineural...

Objective: To investigate the factors influencing sound localization in patients with unilateral sudden sensorineural hearing loss, so as to provide the reference for hearing rehabilitation of patients with unilateral sudden hearing loss. Methods: This study was a cross-sectional study that retrospectively analyzed the clinical data and audiological examination results of 228 patients with unilateral sudden sensorineural hearing loss(103 males and 125 females; aged from 18 to 80 years, with an average age of 46.2 years; 107 cases in the left ear and 121 cases in the right ear; 8 cases of low-frequency decline type, 42 cases of high-frequency decline type, 92 cases of flat decline type, and 86 cases of total deafness type)at the Eye and ENT Hospital of Fudan University from June 2023 to April 2024. The minimum audible angle (MAA) was calculated by the angle discrimination test of 1000 Hz and 4000 Hz warble tones, which were recorded as MAA_{1 000} and MAA_{4 000} according to the frequency of the given sound stimulus. The root mean square error (RMSE) was calculated by the angle recognition test with daily natural sounds as the stimulus sound. Using SPSS 27.0 statistical software, correlation and multiple regression analysis were used to research the clinical factors affecting the ability of sound localization in patients with unilateral sudden sensorineural hearing loss. Results: The mean MAA_{1 000}, MAA_{4 000}, RMSE of patients with unilateral sudden deafness were (53.97±29.14)°, (46.34±28.87)° and (30.06±13.64)°, respectively. Univariate analysis of variance revealed that there were significant differences between different classifications of sudden sensorineural hearing loss for sound localization tests (MAA_{1 000}:F=6.338,P<0.001,MAA_{4 000}:F=14.334,P<0.001,RMSE:F=49.918,P<0.001), post-hoc analysis observed that all significant contrasts were included the type of total deafness and low-frequency deafness. Correlation analysis showed the age of subjects in this study was weak positively correlated to the MAA_{1 000} (r=0.165,P=0.013), the duration of sudden sensorineural hearing loss was weak negatively related to RMSE (r=-0.144,P=0.030), there were significant positive relationships between the threshold of PTA, PTA_1kHz, PTA_4kHz for the affected side, as well as the binaural PTA difference and sound localization test (MAA_{1 000},MAA_{4 000},RMSE) (all P<0.001). The multiple regression analysis showed the age and the binaural PTA difference for the affected side were the significant factors for the MAA_{1 000} and MAA_{4 000}, the binaural PTA difference was the significant factors for the RMSE. The R² of multivariable linear regression model for MAA_{1 000}, MAA_{4 000} and RMSE results in unilateral sudden deafness patients were 0.149, 0.207 and 0.553, respectively. Conclusion: Age, the hearing of the affected side, and binaural PTA difference are the significant factors for sound localization ability in patients with unilateral sudden sensorineural hearing loss, hearing compensation of the affected ear for these patients is hopeful to enhance the sound localization ability.