[A double-blind randomized controlled trial on the efficacy of mixed pure tone sound therapy in chronic tinnitus patients with different hearing loss].

The effectiveness of two different sound therapies in chronic subjective tinnitus was compared. The effectiveness of different degrees of hearing loss patients on two different sound therapies were analyzed preliminarily and the possible mechanisms were discussed. This clinical trial was conducted in the Peking Union Medical College Hospital, China from January 2018 to April 2018. Patients were received sound therapy when they were diagnosed as subjective tinnitus. This was a double-blinded randomized controlled trial. In our clinical trial, we included 56 participants who were randomly divided into Groups A and B with different sound therapies by using a computer allocation sequence. Pure tone audiometry, tympanometry and tinnitus matching were performed. The patients were followed up for 2 weeks, 1 month, 2 months and 3 months. Tinnitus handicap inventory (THI) and visual analog scales (VAS) measuring were used to evaluate the handicap, loudness and anxiety of tinnitus. An analysis of variance (ANOVA) of 2×5 repeated-measures was conducted. With the prolongation of the treatment time, both groups showed significantly lower scores after 3 months training compared with baseline which were measured by THI scores. While there was no effect between the two groups. According to the degree of hearing loss, Group A and B were divided into normal to mild hearing loss group (26-40 dB HL, Group A1, Group B1), moderate to profound hearing loss group (41 dB HL group and above, Group A2, Group B2). In the patients with normal hearing and mild hearing loss, the THI (0.013), VAS loudness and annoyance scores (0.01) after 3 months in Group B1 was significantly lower than those at baseline and the sound therapy in Group B1 was effective. In patients with moderate to profound hearing loss, the THI, VAS loudness and annoyance scores (0.01) after 3 months in Group A2 was significantly lower than those at baseline and the sound therapy in Group A2 was effective. Sound therapy may be effective for some patients. Sound therapy for patients with different degrees of hearing loss are different. The tinnitus of most patients could not disappear completely, but reduce or eliminate. Doctors should use appropriate and individualized acoustic parameters for different characteristics of tinnitus. Doing so would provide effective and specific sound therapy for patients and reduce or eliminate tinnitus.