The contribution of hearing to normal balance

Abstract

Normal balance relies on three sensory inputs: vision, proprioception and the peripheral vestibular system. This study assessed hearing change and postural control in normal subjects. Postural control in 20 normal volunteers was assessed using a Nintendo Wii gaming console and balance board. Each subject was tested standing upright for 30 seconds in a clinic room and a soundproof room with their eyes open, eyes closed, whilst standing on and off foam, and with and without ear defenders. There was significantly more postural sway in the following subjects: those standing with their eyes closed vs those with eyes open (normal room, p = 0.0002; soundproof room, p = 0.0164); those standing on foam with eyes open vs those standing normally with eyes open (in both rooms; p < 0.05); those standing with eyes open in a soundproof room vs a normal room (p = 0.0164); and those standing on foam in a soundproof room with eyes open and wearing ear defenders vs those in the same circumstances but without ear defenders. Our results suggest that this method provides a simple, inexpensive tool for assessing static postural control. Whilst it is recognised that visual input and proprioception play a central role in maintaining posture, our findings suggest that ambient sound and hearing may also have a significant influence.