Tehran University of Medical Sciences Auditory and Vestibular Research 2423-480X 0 0 2026 08 05 1563 1563 Ali Hajimohammadi a. Department of Audiology, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran b. Department of Audiology, School of Rehabilitation Sciences, Shiraz University of Medical Sciences, Shiraz, Iran , Orcid: 0009-0000-2796-6655 Fatemeh Heidari - 2026 04 29 2026 08 05 Background and aim: Bilingualism is linked to modifications in neural pathways that influence auditory processing. Auditory evoked potentials, including auditory late responses (ALRs), are cortical waves generated in response to sound, which provide insights into auditory processing. This study investigated the relationship between simultaneous bilingualism and binaural processing by examining the binaural interaction component (BIC) of ALRs. Methods: This cross-sectional study included fifty-six participants, aged 19 to 30 years, classified into monolingual (Persian) and simultaneous bilingual (Turkish-Persian) groups (MG and BG). ALRs were recorded during both monoaural and binaural stimulation. P1, N1, and P2 latencies, as well as P1-N1 and N1-P2 inter-peak amplitudes, were recorded. The BIC was calculated by subtracting the binaural response waveform from the sum of the summed monaural response waveforms. Results: In binaural stimulation and for the BIC values, BG exhibited shorter mean latencies for all ALR components compared to the MG. This latency reduction reached statistical significance for the P2 component during binaural stimulation and for the N1 and P2 components in the BIC (p<0.05). Mean inter-peak amplitudes showed variability between groups, with the MG demonstrating a significantly greater P1-N1 component amplitude in the BIC (p<0.05). Conclusion: The reduction in latency and BIC amplitude of the ALR components in simultaneous bilinguals suggests possible changes in the auditory cortical processing. Meanwhile, the variability of BIC amplitude highlights the need for caution in interpreting this component. Also, all analyses were performed without correction for multiple comparisons. Therefore, these exploratory findings require confirmation in future studies. https://avr.tums.ac.ir/index.php/avr/article/view/1563 https://avr.tums.ac.ir/index.php/avr/article/download/1563/697