A recent research review suggests that white noise, the soothing, fuzzy soundtrack so many of us rely on to sleep or block out distractions, could actually be dangerous. It argues that exposure to the random, unstructured sounds that make up white noise can alter the brain’s neural connections that help us perceive sound, leaving us at risk of conditions such as tinnitus and even dementia. But there’s reason to be sceptical of some of the authors’ claims.
The review, published last month in JAMA Otolaryngology, mainly looks at the academic literature surrounding tinnitus, a maddening medical condition in which sufferers are plagued by phantom noises of ringing or buzzing. Around 10 percent of American adults have experienced an episode of tinnitus in the past year, according to the National Institute on Deafness and Other Communication Disorders, while 2 million Americans suffer a chronic, debilitating form of it.
Though there’s still a lot we don’t understand about the condition, chronic tinnitus is thought to happen because of misfiring neurons that are responsible for helping us perceive sound. These auditory neurons get constantly activated when they shouldn’t, leading to phantom noises. The overstimulation often happens because the brain tries to compensate for cells elsewhere that have been killed by damaging loud noises or ear infections. Oftentimes, in fact, tinnitus accompanies hearing loss. People with tinnitus and hearing loss are also more likely to develop dementia, suggesting these impairments can affect the brain more widely.
But the researchers behind the current review point out that not all cases of tinnitus can be traced to loud noises. They cite research in animals and people showing that even long-term exposure to non-traumatic noise (below 60 to 70 decibels) seems to make people more likely to develop some of the same neural changes seen in tinnitus sufferers, even in the absence of hearing loss. These changes include slowing down our ability to synchronise audio signals we receive from the outside world and to filter out unneeded auditory information (like sounds from inside our body), as well as making it harder for us to discern certain sounds such as speech.
White noise is a sound that’s a mix of all frequencies the human ear can hear, typically sounding like static or an electronic fan running. Because it can drown other nearby sounds, it’s commonly recommended as a way to manage, if not directly treat tinnitus, when played at low-to-moderate decibels. But the authors further argue that white noise’s lack of structure can worsen tinnitus symptoms. They even go so far as to claim that, much like tinnitus, white noise could possibly “accelerate the ageing of the brain.”
“Increasing evidence shows that the brain rewires in a negative manner when it is fed random information, such as white noise,” said lead author Mouna Attarha, a researcher with the Posit Science Corporation, a California-based company that markets brain-training games through its BrainHQ app, in a statement put out by the company.
But while it’s true there’s growing evidence that chronic non-traumatic noise (around 80 decibels) can impair our hearing over time, even the authors admit there’s only mixed evidence these same noises can affect someone’s risk or progression of tinnitus. And there doesn’t seem to be any direct evidence—cited by the authors in the review or elsewhere—that white noise itself is linked to worse outcomes for tinnitus sufferers. Some recent research, in mice, has even suggested moderate white noise could prevent some of the changes in brain circuitry seen in tinnitus that’s triggered by loud noises. And for what it’s worth, a 2015 study in Germany found that white noise exposure had “no general effect on cognitive functions,” at least in healthy people.
The authors also highlight other emerging treatments for tinnitus which have shown some promise, such as retraining people’s neurons to fire normally again, and sound therapy that relies on structured noises or music. But they also take time to promote their own product, a BrainHQ app, as a potential treatment in the near future.
As evidence, they cited a small study published last year that included 40 volunteers with “severe bothersome tinnitus.” The volunteers were randomized to train with the BrainHQ app or to be a control group that didn’t train with anything. The authors of both that study and the current review noted that slightly more people in the app-training group reported improvements in their symptoms than did the control group. But the difference in improvement between the groups wasn’t statistically significant, which is the bare minimum needed to take any finding seriously. And given the small size of the study, even a positive, significant finding would need to be taken with a grain of salt.
Ultimately, chronic tinnitus is a difficult, complex condition to manage, at least currently. And there are plenty of sufferers who find no real benefit from using white noise to help mask their symptoms. But the authors’ claims that white noise will actively harm their lives seems way too speculative right now, as is the suggestion that white noise could put a person at a higher risk of dementia.
Meanwhile, the rest of the review reads like a subtle advertisement for the brain-training industry, which has a history of inflating how useful its apps are at improving people’s lives. Independent research has found that brain-training games do not improve cognitive function, though they do make you more skilled at playing the specific puzzles you’ve trained on. [JAMA Otolaryngology]