Tehran University of Medical Sciences Auditory and Vestibular Research 2423-480X 0 0 2026 07 20 1545 1545 Zahra Nazmi - Hamid Jalilvand - Mohammad Ebrahim Mahdavi - Alireza Akbarzadeh Baghban - 2026 02 14 2026 07 18 Background and Aim: Age-Related Hearing Loss (ARHL) impairs speech understanding in noise. Acceptable Noise Level (ANL) reflects noise tolerance and predicts hearing-aid outcomes, while Speech-in-Noise (SIN) ability is indexed by Signal-to-Noise Ratio required for 50% correct recognition (SNR-50). Their relationship under binaural listening remains unclear. This study examined binaural ANL and SIN performance in young normal-hearing and older hearing-impaired adults to determine their association and identify audiometric predictors. Methods: Sixty-nine adults participated: 37 young normal-hearing (18–30 years) and 32 older adults with ARHL (60–80 years). Binaural ANL was measured using Persian continuous discourse with 12-talker babble. SIN performance was assessed binaurally using a monosyllabic word test, with SNR-50 estimated by the Spearman-Kärber method. Group comparisons, correlations, and regression analyses examined age effects and audiometric predictors. Results: Older adults showed higher most comfortable levels and ANL values, indicating reduced noise tolerance, and poorer SIN performance with higher SNR-50 and greater variability. Binaural ANL was not associated with SNR-50 in either group. In older adults, SIN performance was predicted by high-frequency thresholds and hearing loss severity, whereas ANL was not a significant predictor. Conclusion: Under binaural conditions, noise tolerance and speech intelligibility are dissociable. In older adults, SIN ability was predicted by high-frequency hearing sensitivity and overall hearing loss severity, whereas ANL was not a significant predictor, underscoring the importance of multidimensional auditory assessment in clinical practice. https://avr.tums.ac.ir/index.php/avr/article/view/1545 https://avr.tums.ac.ir/index.php/avr/article/download/1545/691