Advancing age alters the influence of eye position on sound localization.

Vision and audition provide spatial information about the environment to guide natural behavior. Because the eyes move in the head while the ears remain head-fixed, input conveying eye position in the head is required to maintain audiovisual congruence. Human perception of auditory space was previously shown to shift with changes in eye position, regardless of the target's frequency content and spatial cues underlying horizontal and vertical localization. In this study, we examined whether this interaction is altered by advancing age. Head-restrained young (18-44 yo), middle-aged (45-64 yo), and elderly (65-81 yo) human subjects localized noise bursts under conditions of transient and sustained ocular deflection. All three age groups demonstrated a time-dependent shift of auditory space in the direction of eye position. Moreover, this adaptation showed a clear decline with advancing age, but only for peripheral auditory space (beyond ±10° from midline). Alternatively, adaptation in the periphery may occur, but is more sluggish than in the central field and therefore not fully observed in this experiment. The age-dependent effect cannot be readily explained by senescent peripheral hearing loss, suggesting a change in central processing of auditory space in relation to the control of gaze.