Abstract: Objective To investigate the relationship between the pitch of tinnitus and high frequency hearing threshold(HFHT). Method A total of 156 patients with tinnitus and normal hearing thresholds between 125 and 8 000 Hz were included. Psychoacoustic characteristics of tinnitus and HFHT were recorded. The HFHTs of subjects with normal hearing thresholds but without tinnitus were measured as a control group. The patients were then divided into four groups according to age(25-35 years old, 36-45 years old, 46-55 years old, and ≥55 years old). The patients were divided into nine groups based on their tinnitus pitch: low-frequency group(125 Hz, 250 Hz, and 500 Hz), middle-frequency group(1.5 kHz and 3 kHz), and high-frequency group(4 kHz, 6 kHz, 8 kHz, and ≥9 kHz). The data available from the nine groups and the control group were analyzed. Results No correlation was found between the groups with and without tinnitus. Age, presence of tinnitus, and interaction had significant influence on HFHT. There was no difference between the low-frequency and control groups. In the middle-frequency group, there was significant hearing loss related to frequency, including at 9 kHz in the 1.5 kHz group and at 11.2 kHz in the 3 kHz group. In the high-frequency group, there was significant hearing loss related to frequency, including at 10 kHz in the 4 kHz group, at 10 kHz and 11.2 kHz in the 6 kHz group, at 10 kHz in the 8 kHz group, and at 10 kHz and 12.5 kHz in ≥9 kHz group. The hearing levels at 11.2 kHz in the 8 kHz and ≥9 kHz groups were statistically significantly lower than those in the control group(P<0.01). Conclusion HFHT correlated with age and presence of tinnitus. The decrease of hearing thresholds at 10 kHz and 11.2 kHz in the middle-frequency and high-frequency groups may be a sensitive indicator for alterations in the basal cochlea, which could lead to clinical therapy for high-frequency tinnitus.

Key words: High frequency hearing threshold, Psychoacoustic characteristics, Tinnitus