Hearing, self-motion perception, mobility, and aging.

Hearing helps us know where we are relative to important events and objects in our environment and it allows us to track our changing position dynamically over space and time. Auditory cues are used in combination with other sensory inputs (visual, vestibular, proprioceptive) to help us perceive our own movements through space, known as self-motion perception. Whether we are maintaining standing balance, walking, or driving, audition can provide unique and important information to help optimize self-motion perception, and consequently to support safe mobility. Recent epidemiological and experimental studies have provided evidence that hearing loss is associated with greater walking difficulties, poorer overall physical functioning, and a significantly increased risk of falling in older adults. Importantly, the mechanisms underlying the associations between hearing status and mobility are poorly understood. It is also critical to consider that age-related hearing loss is often concomitant with declines in other sensory, motor, and cognitive functions and that these declines may interact, particularly during realistic, everyday tasks. Overall, exploring the role of auditory cues and the effects of hearing loss on self-motion perception specifically, and mobility more generally, are important to both building fundamental knowledge about the perceptual processes underlying the ability to perceive our movements through space, as well as to optimizing mobility-related interventions for those with hearing loss so that they can function better when confronted by everyday, real-world, sensory-motor challenges. The goal of this paper is to explore the role of hearing in self-motion perception across a range of mobility-related behaviors. First, we briefly review the ways in which auditory cues are used to perceive self-motion and how sound inputs affect behaviors such as standing balance, walking, and driving. Next, we consider age-related changes in auditory self-motion perception and the potential consequences to performance on mobility-related tasks. We then describe how hearing loss is associated with declines in mobility-related abilities and increased adverse outcomes such as falls. We describe age-related changes to other sensory and cognitive functions and how these may interact with hearing loss in ways that affect mobility. Finally, we briefly consider the implications of the hearing-mobility associations with respect to applied domains such as screening for mobility problems and falls risk in those with hearing loss and developing interventions and training approaches targeting safe and independent mobility throughout the lifespan.