Maintaining balance is a complex process that involves input from multiple sensory systems, including the vestibular system in the inner ear, visual cues, and proprioception from the body’s muscles and joints. While visual stimuli have long been known to impact balance, new research suggests that sound can also play a critical role—especially for individuals with vestibular disorders.
A recent study published in PLOS ONE examined the effects of auditory stimuli on postural stability in individuals with vestibular hypofunction. The research, led by Anat Lubetzky, associate professor of physical therapy at NYU Steinhardt School of Culture, Education, and Human Development, found that certain sounds significantly increased balance disturbances in affected individuals when combined with visual motion.
A study participant stands on a force platform that measures body movements, while the headset measures head movements. Photo credit: Anat Lubetzky, NYU
Virtual Reality Subway Experiment
The study involved 61 participants, split into two groups: healthy individuals and those diagnosed with unilateral vestibular hypofunction—a condition where one side of the vestibular system is impaired, leading to dizziness, imbalance, and difficulties in visually dynamic environments.
To assess the impact of sound on balance, researchers used virtual reality (VR) simulations of a New York City subway environment. Participants wore a VR headset while standing on a force platform that measured body movement (sway), and the headset itself tracked head movement. The VR simulation presented different scenarios:
- A static subway environment with no movement
- A moving subway scene without sound
- A moving subway scene with white noise
- A moving subway scene with actual subway sounds
By comparing sway patterns across these conditions, researchers observed that participants with vestibular hypofunction experienced significantly greater instability when auditory stimuli were present.
This effect was observed with both white noise and subway sounds, suggesting that real-world sounds may interfere with the brain’s ability to compensate for balance deficits.
Key Findings
The study produced several notable findings:
- Sound exacerbates balance difficulties in individuals with vestibular hypofunction, particularly when paired with moving visual stimuli.
- Both white noise and real-world sounds were disruptive, indicating that general auditory input—not just context-specific environmental noise—can contribute to balance instability.
- No significant impact on healthy individuals, suggesting that a functioning vestibular system can compensate for auditory input in balance control.
- Increased body sway was observed in multiple directions, including forward-backward shifts and head movements in different planes.
Screen capture from an NYU custom-made Unity app developed by Courant postdoctoral researcher Zhu Wang. Credit: NYU
According to Lubetzky, the findings highlight the need for a more comprehensive approach to balance assessment and therapy:
“People with vestibular hypofunction have difficulty in places like busy streets or train stations where the overwhelming visual information may cause them to lose balance or be anxious or dizzy. Sounds are not typically considered during physical therapy, making our findings particularly relevant for future interventions.”
Implications for Vestibular Rehabilitation
These findings challenge traditional approaches to vestibular rehabilitation, which often focus primarily on visual and movement-based therapies. The study suggests that sound should be integrated into both assessment and treatment strategies for balance disorders.
Lubetzky emphasizes that incorporating real-world sounds into balance training programs could improve patient outcomes:
“What we’ve learned is that sound should be included as part of both the assessment of balance and intervention programs. Because balance training is known to be task-specific, ideally, these should be real sounds related to patients’ typical environments and combined with salient and increasingly challenging visual cues.”
With the increasing availability of portable VR headsets, clinicians may have new tools to create more realistic, immersive rehabilitation environments. By simulating real-world scenarios—including both visual and auditory stimuli—therapists can help patients gradually adapt to challenging balance environments in a controlled setting.
Future Directions
The research opens avenues for further investigation into how different types of sounds (e.g., speech, traffic noise, music) may uniquely impact individuals with vestibular disorders. Future studies may also explore whether targeted auditory training—such as gradual exposure to disruptive sounds—could help desensitize patients and improve overall stability.
The study was supported by grants from the National Institute on Deafness and Other Communication Disorders (R21DC018101), as well as resources from the Icahn School of Medicine at Mount Sinai and the National Center for Advancing Translational Science (UL1TR004419).
As Lubetzky and her colleagues continue to explore the connections between sensory inputs and postural stability, the hope is to develop more effective therapies that enhance quality of life for those with vestibular impairments.
Citation
Lubetzky AV, Cosetti M, Harel D, Sherrod M, Wang Z, et al. (2025) Real sounds influence postural stability in people with vestibular loss but not in healthy controls. PLOS ONE 20(1): e0317955. https://doi.org/10.1371/journal.pone.0317955
