Tinnitus pitch does not always fall within the frequency range of hearing loss - a cross-sectional study on the mechanism of tinnitus production.

BACKGROUND: Clinically, we find that tinnitus patients often have hearing loss. According to the most accepted mechanism of tinnitus, that is, the spontaneous discharge and abnormal synchronization of neurons after afferent reduction, tinnitus frequency is closely related to the frequency of hearing loss.

OBJECTIVE: The purpose of this study was to investigate the correlation of tinnitus pitch with the frequency of hearing loss.

MATERIALS AND METHODS: A total of 500 patients with unilateral or bilateral chronic tinnitus were enrolled in this study. All patients underwent pure tone audiometry (PTA) and tinnitus acoustic examination. Hearing loss levels and frequencies were recorded. The relationship between tinnitus pitch and hearing loss level and frequency was statistically analyzed.

RESULTS: Our results showed that 96.6% of the 500 tinnitus patients had hearing loss. Statistical analysis showed that low frequency (LF) tinnitus was correlated with LF hearing loss, but moderate frequency & high frequency (MF&HF) tinnitus was not significantly associated with MF&HF hearing loss. The coincidence of tinnitus pitch with the highest hearing threshold correlated with the degree of hearing loss.

CONCLUSION AND SIGNIFICANCE: The vast majority of patients with chronic subjective tinnitus had hearing loss, and the frequency of tinnitus correlated with the degree and frequency of hearing loss but not exactly fall within the frequency range of hearing loss.