Greater Severity of Hearing Loss is Associated with Worse Balance Performance but Exercise may Improve Stability

Introduction: Understanding why bilateral sensorineural hearing loss (BHL) is associated with balance dysfunction can guide balance rehabilitation programs. We investigated whether adults with BHL demonstrated impaired standing balance and increased postural visual and somatosensory dependence as compared to those with normal hearing. Methods: This cross-sectional study assessed postural sway in 31 adults with BHL (mean age=72.97) and 28 controls (mean age=59.14), using the instrumented modified Clinical Test of Sensory Integration (mCTSIB). The mCTSIB has 4 tasks, each 30-second long: standing with eyes open/closed on floor/foam. Outcome measures, calculated from inertial measurement units, included overall stability (root-mean-square [RMS] sway, ms²) and smoothness of sway (anterior-posterior and medio-lateral jerk, m²s⁵). Participants also self-reported whether they exercised on a regular basis. Results: Adjusting for age, both groups increased RMS and jerk significantly with task, with no significant differences between groups. Greater BHL severity moderately correlated with higher anterior-posterior jerk and RMS in foam eyes closed condition. Age showed no more than weak correlations with BHL severity, jerk, or RMS. As a post-hoc analysis we observed that people who reported exercising regularly exerted less effort to maintain stance and were significantly more stable on the most challenging tasks. Conclusions: Individuals with BHL did not show increased visual or somatosensory reliance and overall as a group showed similar balance performance to adults with normal hearing. Greater severity of hearing loss was associated with worse performance regardless of age. This study supports the role of regular exercise as protective against balance dysfunction in aging with or without hearing loss.