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 unclear.

Conserved features of eye movement related eardrum oscillations (EMREOs) across humans and monkeys

“…[3][4][5][6]9,[11][12][13][14][15][16][17][18][19][20][21][22][23]49,50]; see also [7,8]). The discovery of EMREOs in both humans and monkeys [27][28][29][30][31][32] afforded an opportunity to study an early aspect of this process in the same way in two different species. Given that how EMREOs actually contribute to auditory coordinate transformations has not yet been established, a comparison between human and monkey EMREOs provides an opportunity to identify clues as to which aspects of the EMREO signal are conserved across species.…”

“…[24][25][26]), the impact of such signals might produce movements of the eardrum that could be detected by microphones in the ear canal. This led to the discovery of eye movement-related eardrum oscillations (EMREOs) [27][28][29][30] and inquiries into their relationship to visual and auditory perception [31,32].…”