Tehran University of Medical Sciences Auditory and Vestibular Research 2423-480X 28 3 2019 06 17 190 197 Athareh Farahani Department of Audiology, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran Saeid Farahani Department of Audiology, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran Nematollah Rouhbakhsh Department of Audiology, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran Farzaneh Zamiri Abdollahi Department of Audiology, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran Masoud Bolandi Department of Audiology, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran 2019 02 07 2019 04 15 Background and Aim: Temporal processing is affected in people exposed to occupational noise. The primary goal of this study was to evaluate the temporal processing of people exposed to occupational noise of more than 85 dB A but have not experienced clinically significant changes at hearing thresholds at conventional frequencies. Methods: A comparison between groups were designed using individuals exposed to occupational noise (n = 15 as the case group) and non-exposed individuals (n = 16 as the control gro­up). Two groups were age-matched (p < 0.05). The extended high-frequency audiometric thre­sholds and temporal processing system were evaluated through a duration pattern sequence test. Finally, the correlation between the extended high-frequency hearing thresholds and the duration pattern test scores was investigated. Results: The case group had significantly higher hearing thresholds than the control group at 14, 15, and 16 kHz (p < 0.05). Although in other frequencies, the mean hearing thresholds in the case group was higher than the control group, the difference was not significant. Also, the case group had significantly lower duration pattern sequence scores than the control group in the right (p = 0.02) and the left ears (p = 0.03). There was no correlation between extended high-frequency hearing thresholds and duration pattern sequence test scores. Conclusion: In people exposed to occupational noise, both extended high-frequency thresholds and temporal processing in lower frequency ran­ges (with normal hearing thresholds) are interrupted. https://avr.tums.ac.ir/index.php/avr/article/view/795 https://avr.tums.ac.ir/index.php/avr/article/download/795/333