Evaluation of differential sensitivity for frequency, intensity, and duration around the tinnitus frequency in adults with tonal tinnitus

Abstract

OBJECTIVES: The perceptual characteristics of tinnitus are usually assessed by a matching procedure, where loudness and pitch of an external sound are matched to those of the tinnitus percept. The duration discrimination test (DDT), differential limen for intensity (DLI) and differential limen for frequency (DLF) are relatively simple psychoacoustic methods of measuring differential sensitivity. MATERIALS and METHODS: 15 participants with normal or minimal hearing loss with tinnitus in the age range of 18 to 40 years were enrolled in the present study. Pure tone audiometry (PTA), immittance audiometry and otoacoustic emissions were done to diagnose the degree of hearing loss. Duration discrimination test (DDT), differential limen for intensity (DLI) and differential limen for frequency (DLF) was administered on all the participants using MATLAB software (MLP toolbox) at the matched tinnitus frequency, half an octave below & above the frequency. RESULTS: The results show that there was a significant increase in DDT, DLI and DLF thresholds at the tinnitus frequency compared to half an octave above and below the matched frequency. The result suggests that differential sensitivity abilities regarding frequency, intensity, and duration are affected at the tinnitus frequency in individuals with tinnitus. CONCLUSION: The results of the study suggest that the differential sensitivity ability is affected in individuals with tinnitus especially at the frequency of tinnitus.