[The changes and analysis of the ability of sound localization for patients with unilateral sudden hearing loss during the early period of treatment].

Objective: To assess the sound localization ability of patients with unilateral sudden hearing loss during the early period of treatment, to explore its changing characteristics and to analyze influencing factors. Methods: A total of 22 patients with unilateral sudden sensorineural hearing loss, with onset within 3 days, who were hospitalized at Shandong Provincial ENT Hospital between January and April 2024, were collected in this study. The cohort included 13 males and 9 females, with a mean age of 36.5 years. Among them, 10 suffered in the right ear and 12 in the left ear. Additionally, 15 healthy individuals (8 males and 7 females, mean age 29.2 years) were selected as controls. Pure tone audiometry and sound localization tests were reviewed on the first day, third day, fifth day of admission; the third week after onset, and the pure tone average and the root-mean-square error(RMSE) were used as indicators, respectively. The improvement of the ability of sound localization and pure tone average were assessed by correlation analyses using SPSS, version 27.0, and multiple regression analysis was employed to explore effects that might influence sound localization ability. Results: The pure tone threshold and sound localization ability on the third week of onset were improved compared with those on the initial three instances(the first, third, and fifth days of admission). 9 of the 22 patients (40.91%, 9/22) presented normal sound localization ability whereas their hearing loss had not recurred yet. The Spearman correlation analysis revealed a significant positive correlation between the improvement of sound localization ability and hearing improvement (r=0.57, P<0.001). Meanwhile, multiple regression analysis showed that hearing threshold was a significant factor for sound localization when there was audible frequency. Vice versa, at this circumstance, ages and vertigo were significant factors. Conclusions: For most of the patients with unilateral sudden hearing loss, ability of sound localization improves with the decrease of hearing threshold. Notably, some patients can restore normal levels of sound localization for white noise, even in the presence of hearing loss at certain frequencies, by relying on binaural acoustic cues provided by residual hearing.