We know balance is a complex integration of multiple sensory systems, I like to call, the Balance Trifecta. These sensory systems include vision, somatosensory (or sensation), and our vestibular system (that gyroscope-like complex in our inner ear). But could hearing make up the quadfecta of balance?
When we think of balance, we can think of our ability to stay upright and not fall down. But balance is also various sensory systems telling our brain where we are in space, otherwise know as spatial orientation. These sensory systems (vision, somatosensory, and vestibular) constantly send messages to our brain about where we are relative the objects, beings, and world around us (vision); what type of surface we are walking, running, or sitting on (somatosensory); and in which direction we are moving and which way is up and down, or our gravitational pull (vestibular). So, does hearing give our brain additional information about where we are in space? I would say absolutely!
I am hear, not there
In spirit of the current World Cup, think about the sport of Blind Soccer (or Blind Football if you're not American). In this sport, players are either vision impaired, or partially or completely blind. To even the playing field, all players must wear eye shields which completely occlude their vision. The ball makes a rattling sound so players can localize where the ball is at any given time. Simultaneously, they are listening to the sounds (footsteps, voices, movement) of players around them. This is why when watching a game of blind soccer, the crowd must be silent. Each player has a constantly shifting mental map of where the ball, their team, and their opponents are at all times, relative to their own position in space. TADA! Spatial orientation! And they are using multiple auditory cues to achieve a very high level of spatial orientation.
A recent systematic review looked at various studies comparing the effect hearing has on balance (1). While there needs to be more research in this area with larger sample sizes and more controlled variables, this systematic review found that the use of hearing aids in individuals with hearing impairment has a significant effect on their static balance. Static balance is our ability to balance without moving, so standing or sitting. A couple of proposed mechanisms for this are:
The use of auditory cues from our surroundings allows us to create a 3-dimensional spatial hearing map, telling our brain where we are in space (like the Blind Soccer players).
With the use of hearing aids, our brain doesn't have to work as hard to try and hear the world around us. In other words, the cognitive demand on the brain is lessened, allowing more brain capacity to be allocated to maintaining balance.
This latter point is evidenced in my work with older adults with dementia. When given a straight forward balance task, they may do fairly well. However, when given the same balance task, while asking them to count backwards by 7 or spell their grandchildren's names backwards (increased cognitive demand), their balance deteriorates.
Interestingly, a systematic review looking at the correlation of hearing loss and falls, found that older adults with hearing loss were 2.4 times more likely to fall than older adults with normal hearing. And one study of people aged 40-69 found that even mild hearing loss of approximately 25 decibels increases your risk of falling by 3-fold (3). This is why I always ask about hearing and the use of hearing aids when working on balance with all my patients, especially older adults with signs of dementia.
Conversely, this same systematic review looking at the effects of hearing aids on balance found no significant effects of hearing on dynamic balance (1). Dynamic balance is our body's ability to maintain balance while moving (walking, turning, playing elite soccer). The thought here, is that because your body is moving, your brain is receiving more signals from the vestibular system and leveraging that system (more than hearing) for spatial orientation. However, further research is warranted.
The Earie Truth
So while we know vision, somatosensory, and our vestibular system all play key roles in balance. We are beginning to recognize the impact hearing has on our static balance and risk for falls. For this reason, if you are experiencing problems with balance, make sure you get your hearing checked regularly and wear any hearing assistive devices prescribed. You can also get an evaluation by a vestibular physical therapist. A vestibular physical therapist will assess each of your balance systems, while screening for hearing impairments.
Mahafza MT, Wilson WJ, Brauer S, Timmer BHB, Hickson L. A Systematic Review of the Effect of Hearing Aids on Static and Dynamic Balance in Adults with Hearing Impairment. Trends in Hearing. 2022;26:233121652211210.
Jiam, N. T. L., Li, C., & Agrawal, Y. (2016). Hearing loss and falls: A systematic review and meta–analysis. The Laryngoscope, 126(11), 2587–2596.
Lin FR, Ferrucci L. Hearing loss and falls among older adults in the United States. Arch Intern Med. 2012 Feb 27;172(4):369-71.