The vestibular system is a network of organs in the inner ear that detects head movements and position. The brain uses this information, along with input from the eyes and joints, to maintain the body’s balance.
Visual information has long been shown to affect balance (for example, strobe lights and swirling images can cause instability), but a new study published in PLUS ONE shows that sounds can also be a disturbing factor for those who have vestibular hypofunction, a disorder of the vestibular system that results in impaired balance.
“People with vestibular hypofunction have difficulty in places such as busy streets or train stations, where overwhelming visual information can cause loss of balance, anxiety or dizziness,” says lead author Anat Lubetzky, associate professor of physical therapy at the School of Culture. Steinhardt of New York University. , Education and Human Development. “Sounds are not typically considered during physical therapy, which makes our findings particularly relevant for future interventions.”
The researchers carried out an experiment with 69 participants divided into two groups: healthy controls and individuals with unilateral vestibular hypofunction (affecting one ear).
Participants wore a virtual reality headset that simulated the experience of being on the New York City subway. While experiencing the sights and sounds of the “subway,” they stood on a platform that measured their body movement (known as sway), while headphones recorded the movement of their head, two indicators of balance. Participants were provided with different subway scenarios: still or moving images combined with silence, white noise, or recorded subway sounds.
The results revealed that for the vestibular hypofunction group, moving images accompanied by audio (either white noise or subway sounds) produced the greatest amount of influence. This sway was evident by forward and backward body movements, as well as left-to-right head movements and up-and-down head tilts. Audio conditions did not affect the balance of healthy individuals.
“What we have learned is that sound should be included as part of both balance assessment and intervention programs,” Lubetzky says. “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. “Wearable virtual headsets are a promising tool for both assessing and treating balance problems.”
Funding for this study came from a grant from 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). .