The Effects of Hearing Loss on Balance: A Critical Review.

Recent epidemiological findings of associations between hearing loss (HL) and poorer mobility and higher falls risk have increased the demand for ecologically valid experimental research to determine the potential mechanisms underlying human hearing-balance relationships. This review provides an overview of the laboratory-based approaches to studying human balance, identifies crucial factors that should be considered to improve the ecological validity of hearing-balance research, and provides a critical review of the scientific literature to date on the effects of HL on balance. Most present studies can be subdivided into those that examine balance changes due to the effects of (1) auditory suppression in individuals with normal hearing, (2) HL with and without hearing aids, and (3) cochlear implants in children and adults. To allow for meaningful comparisons, we based our in-depth critical review on studies that met minimum criteria of having at least one objective kinetic or kinematic measure of standing balance during a two-legged stance with feet side-by-side, for at stance duration of at least 30 sec. With this minimum criterion in place, we found mixed evidence that hearing suppression, HL, or hearing devices affects postural stability, especially when other sensory information is available and/or reliable, and task demands are relatively low. However, hearing may become more important when multiple sensory systems become unreliable, task demands, or cognitive impairments are greater, or when sounds provide important auditory cues to assist with orientation or provide early detection of an impending balance disturbance. However, more research is clearly needed, because there is a wide range of technical and experimental differences and limitations observed across the present literature. To address these gaps, we have provided a number of recommendations and suggested priorities for future research to provide the ecologically valid, reliable, and reproducible evidence needed to uncover any potential relationships between HL, balance, and falls.