The Effect of Different Auditory Stimuli and Optokinetic Stimuli on Vestibulo‐Ocular Reflex Function

This study investigated how auditory stimuli and optokinetic stimulation modulate functional Head Impulse Test (fHIT) correct response rate (CR%) across semicircular canals (SCCs) and the associated cognitive load in healthy adults. Fifty participants (20-57 years) completed repeated-measures fHIT under four conditions: silence, music, white noise, and optokinetic stimulation. The CR% from all SCCs were recorded and workload was assessed with the NASA Task Load Index (NASA-TLX). Optokinetic stimulation produced the most significant CR% decrement (e.g., right lateral 90 vs. 100 in silence; p<0.001) and the highest workload (median NASA-TLX = 50). Auditory conditions produced minimal CR% changes. Across conditions, lateral SCCs were less affected than vertical SCCs by sensory and cognitive interference. Visual-vestibular conflict markedly reduced CR%, whereas auditory effects appeared indirect and attention mediated. These findings provide normative benchmarks for multisensory fHIT assessment.