Unilateral Tinnitus Caused by Cerumen Impaction and Stochastic Resonance

Abstract

Objectives: The objectives of this study were: (i) To investigate hearing lost in patients with tinnitus caused by cerumen impaction before and after cerumen removal and its relationship to the tinnitus. (ii) To discuss possible role of synaptic noise by mechanism of stochastic resonance. Methods: Nine patients, who had unilateral tinnitus and cerumen impaction, were selected for the study. Standard audiometric evaluation was performed, including case history, and measures of hearing sensitivity at 0.25-8 kHz. The testing protocol had three response tasks: threshold testing, loudness matching, and pitch matching. The time after cerumen removal to the end of tinnitus was measured. Results: In all patients the tinnitus disappeared in 20 minutes after cerumen removal. Control audiometry five minutes after cerumen removal showed recovery of normal hearing. Conclusion: Fast dissipation of tinnitus after cerumen removal and recovery of normal hearing shows possible connection between mechanism of weak signal enhancement for example by mechanism of stochastic resonance and tinnitus. Such a mechanism may also explain presence of tinnitus in individuals with intact auditory perception. Study conducted at Otorhinolaryngology Outpatient Clinic, Rychnov nad Kneznou The work has been supported by the research grant of the Faculty of Chemical Engineering of the Institute of Chemical Technology, Prague No. MSM 6046137306.