Eye movement-related eardrum oscillations (EMREOs) occur without visual input but are reduced during closed eyelids.

Recent investigations have shown that the tympanic membranes exhibit synchronous oscillations with each saccadic eye movement (Gruters et al., 2018), a phenomenon known as eye movement-related eardrum oscillations (EMREOs). However, the dependence of these saccade-associated EMREOs on ongoing visual activity remains to be elucidated. Given the direct projections from motor areas to primary auditory and visual cortices and the observation that EMREOs’ onset occurs concurrently with, or even precedes, saccades, we hypothesized that EMREOs would persist in the absence of visual stimulation. This report presents a study wherein sixteen healthy, male and female participants, executed horizontal saccades under three distinct conditions: i) in a well-lit environment, ii) in a darkened environment with eyes open, and iii) in a darkened environment with eyes closed. Ocular movements were quantified via electrooculography, and tympanic membrane oscillations were registered using in-ear microphones. The results demonstrated the presence of EMREOs concurrent with both visually guided and memory-guided saccades, although a late minor reduction in amplitude was observed in the 'dark with open eyes' condition. Significant attenuation of EMREOs was evident when participants performed saccades with their eyelids closed, despite maintaining the same saccade amplitude and initial velocity. This amplitude reduction may reflect modulations in cortical states associated with predictive coding. Significant Statement Eye movement-related eardrum oscillations (EMREOs) occur synchronously with saccadic eye movements and persist even in the absence of visual input, indicating that visual stimuli do not solely drive these oscillations. However, the amplitude of EMREOs decreases slightly when saccades are made in darkness and strongly decreases with eyes closed, despite consistent saccade metrics. This attenuation suggests that EMREOs are modulated by cortical states associated with predictive coding rather than just motor commands or sensory feedback. These findings highlight a complex interaction between motor activity, sensory processing, and cortical predictive mechanisms.