The efficacy of tympanum injection and posterior auricular injection in diabetes with sudden hearing loss (SHL) was analyzed. A mobile terminal-based portable pure tone audiometry system and its processing method were established. Based on mobile terminals, a portable pure tone audiometry system including an Android system, pure sound signal generation, pure tone hearing threshold, and client module was established. A masking model and self-adaptive algorithm were used to detect and reduce noise. Besides, the performance of the portable pure tone audiometry system was detected. A total of 46 diabetes patients with SHL diagnosed at the otolaryngology department in BeiChen Hospital between August 2019 and November 2021 were selected as the research objects and randomly divided into the retroauricular group (posterior auricular injection) and the tympanic group (tympanum injection). Each group included 23 cases. All patients received pure tone audiometry (PTA) before and after the treatment. The changes in fasting blood glucose (FPG), 2h postprandial blood glucose (2hPG), and glycosylated hemoglobin (HbA1c) of the patients were monitored before and after the treatment. Besides, tinnitus loudness visual analog scale (VAS), pain VAS, efficacy, and the incidence of adverse reactions of the patients in two groups were compared. The results indicated that the hear threshold error detected by the medical audiometer and a portable pure tone audiometry system was within 2dB. Before the optimization, there was an error of about 10dB between the hear thresholds detected by the self-adaptive algorithm and a medical audiometer. After the treatment, the hear threshold and average PTA of the patients in the retroauricular and the tympanic groups under different frequencies were both reduced compared with those before the treatment ( P < 0.05 ). The tinnitus VAS score in the retroauricular group was decreased more notably than that in tympanic group ( P < 0.01 ), and the pain VAS score was much lower than that in the tympanic group ( P < 0.001 ). The comparison of FPG, 2hPG, HbA1c, the proportions of cured, significantly effective, effective, ineffective patients, and the total effective rate in the patients in the retroauricular and the tympanic groups before and after the treatment all showed no statistical differences ( P > 0.05 ). The incidence of adverse reactions in tympanic group after the treatment was dramatically higher than that in retroauricular group ( P < 0.001 ). The above results demonstrated that posterior auricular injection showed potential application values in the treatment of SHL with diabetes and established a portable pure tone audiometry system as well as its noise processing method.