Detection of Spatially Localized Sounds Is Robust to Saccades and Concurrent Eye Movement-Related Eardrum Oscillations (EMREOs).

Abstract

Hearing is an active process, and recent studies show that even the ear is affected by cognitive states or motor actions. One example are movements of the eardrum induced by saccadic eye movements, known as "eye movement-related eardrum oscillations" (EMREOs). While these are systematically shaped by the direction and size of saccades, the consequences of saccadic eye movements and their resulting EMREOs for hearing remain unclear. We here studied their implications for the detection of near-threshold clicks in human participants. Across three experiments, sound detection was not affected by their time of presentation relative to saccade onset, by saccade amplitude or direction. While the EMREOs were shaped by the direction and amplitude of the saccadic movement, inducing covert shifts in spatial attention did not affect the EMREO, suggesting that this signature of active sensing is restricted to overt changes in visual focus. Importantly, in our experiments, fluctuations in the EMREO amplitude were not related to detection performance, at least when monaural cues are sufficient. Hence, while eye movements may shape the transduction of acoustic information, the behavioral implications remain to be understood.SIGNIFICANCE STATEMENT Previous studies suggest that oculomotor behavior may influence how we perceive spatially localized sounds. Recent work has introduced a new perspective on this question by showing that eye movements can directly modulate the eardrum. Yet, it remains unclear whether this signature of active hearing accounts for behavioral effects. We here show that overt but not covert changes in visual attention modulate the eardrum, but these modulations do not interfere with the detection of sounds. Our results provide a starting point to obtain a deeper understanding about the interplay of oculomotor behavior and the active ear.