Tehran University of Medical Sciences Auditory and Vestibular Research 2423-480X 0 0 2026 05 17 1536 1536 Sadegh Jafarzadeh Department of Audiology, School of Paramedical and rehabilitation Sciences, Mashhad University of Medical Sciences, Mashhad, Iran Arash Ziaee Sinus and Surgical Endoscopic Research Center, Mashhad University of Medical Sciences, Mashhad, Iran 2026 01 10 2026 04 29 Abstract Background and Aim: Tinnitus is common but varies in severity. Evidence suggests central mechanisms drive handicap. This study estimates adult tinnitus prevalence and Tinnitus severity in Mashhad and examines links between Tinnitus Handicap Inventory (THI), hearing handicap, pure-tone averages (PTA), WHO impairment grades, and age-corrected NIHL-like patterns. Methods: This is a population-based cross-sectional study (May 2024–March 2025) included a stratified cluster random sample of 2,186 adults aged 20–85, who completed Persian THI, and hearing handicap inventories. They underwent PTA and speech discrimination testing. Hearing graded per WHO. NIHL patterns screened using Coles–Lutman–Buffin criteria applied to uncorrected and ISO 7029 age-corrected thresholds. Analyses used non-parametric tests; robust and median quantile regression for continuous outcomes; beta-binomial GLM for speech discrimination; proportional-odds logistic regression for WHO grades; and logistic regression for NIHL; models adjusted for age and sex. Results: Tinnitus prevalence was 19.9%; 67.8% had slight/mild handicap, and ~3% had THI ≥38. THI correlated moderately with hearing handicap (ρ=0.361) and weakly with PTA (ρ=0.122). Each THI point increased the odds of worse WHO grades by 1.4% and predicted poorer speech discrimination (~14% lower odds per 10-point increase; OR≈0.86). THI did not predict age-corrected NIHL classification (OR=0.998; non-significant). THI, more than thresholds, predicted perceived hearing handicap. Conclusions: In Mashhad, tinnitus is common yet low-impact, with only 1 in 30 adults experiencing clinically significant handicap. This supports a neurocognitive framework emphasizing limbic/attentional factors over audiometric patterns, suggesting that routine speech testing should accompany tinnitus assessments. https://avr.tums.ac.ir/index.php/avr/article/view/1536 https://avr.tums.ac.ir/index.php/avr/article/download/1536/682