The vestibular system consists of a set of organs located in the inner ears that are responsible for sensing the movements and position of the head. The brain utilizes this information, along with data from the eyes and joints, to help keep the body balanced.
Research has long established that visual stimuli can impact balance—consider how strobe lights and spinning images may lead to feelings of instability. However, a recent study published in PLOS ONE indicates that sounds can also interfere, especially for individuals with vestibular hypofunction, a disorder of the vestibular system that leads to balance issues.
“People with vestibular hypofunction often struggle in crowded environments such as busy streets or train stations, where excessive visual information may trigger feelings of instability, anxiety, or dizziness,” explains lead author Anat Lubetzky, an associate professor of physical therapy at NYU Steinhardt School of Culture, Education, and Human Development. “Sound factors are typically overlooked in physical therapy, which makes our findings particularly significant for future treatment approaches.”
The study involved 69 participants who were split into two groups: healthy controls and individuals suffering from unilateral vestibular hypofunction (impacting one ear).
Participants donned a virtual reality headset that mimicked the experience of being in a New York City subway. While immersed in the visuals and sounds of the “subway,” they stood on a platform designed to measure their body sway, while their head movements were recorded as indicators of balance. Participants were exposed to various subway scenarios that varied in visuals—either static or dynamic—combined with silence, white noise, or actual subway sounds.
The findings showed that individuals with vestibular hypofunction exhibited the most sway when faced with moving visuals in conjunction with audio (either white noise or subway sounds). This sway was characterized by forward and backward body movements, as well as side-to-side head movements and tilting of the head. The audio conditions did not influence the balance of the healthy participants.
“Our results indicate that sound should be considered in both balance assessments and intervention strategies,” Lubetzky notes. “Since balance training is known to be specific to tasks, it would be most effective to use sounds that mimic the patients’ usual environments coupled with prominent and progressively challenging visual cues. Portable virtual headsets emerge as an encouraging tool for assessing and treating balance issues.”
The research received funding from a grant by the National Institute on Deafness and Other Communication Disorders (R21DC018101), resources from the Icahn School of Medicine at Mount Sinai, and a grant from the National Center for Advancing Translational Science (UL1TR004419).
