March to the Beat of Your Own Eardrum

It is well known that there is communication between the auditory and the visual system. Audiologists frequently take advantage of this relationship in balance system diagnostics as related to the vestibular-ocular reflex (VOR). Yet, new findings suggest this relationship is not limited to the inner ear.

A recent study out of Duke University (Gruters et al, 2018) demonstrated that saccadic movements of the eye to visual targets resulted in a conjugated movement of the eardrum. The eardrum motion was oscillatory and began as early as 10 months before the saccade onset. The investigators dubbed the phenomenon eye movement-related eardrum oscillations (EMREOs).

The authors speculate the source of the EMREO may derive from a copy of the motor command to generate the eye movement, which may then engages middle-ear muscles, though further work is needed to define the pathway (see Gruters et al, 2018). The eardrums move when the eyes move: A multi-sensory effect on the mechanics of hearing (PNAS, prepub).

Reference

Gruters KG, Murphy DLK, Jenson CD, Smith DW, Shera CA, Groh JM. (2017)  The eardrums move when the eyes move: A multisensory effect on the mechanics of hearing. Proceedings of the National Academy of Sciences (PNAS) of the United States. December 7.