Those who have never endured the relentless torture of tinnitus can only dream. In fact, nightmares may be the closest some people come to experiencing something similar.
Subjective sounds can also be hisses, buzzes, or clicks that are not heard by others and may be constant or may come and go.
Neuroscientists at the University of Oxford now suspect that sleep and tinnitus are closely linked in the brain.
Their findings hint at a fundamental relationship between the two conditions—one that, surprisingly, had been overlooked in the brain until recently.
“What first intrigued my colleagues and me were the striking similarities between tinnitus and sleep,” Linus Milinski, a neuroscientist at the Oxford Institute for Sleep and Circadian Neuroscience, told ScienceAlert.
“Tinnitus is a debilitating condition, and sleep is a natural state that we enter on a regular basis, but both appear to rely on spontaneous brain activity. Since there are still no effective treatments for subjective tinnitus, I believe exploring these similarities may provide new ways to understand and ultimately treat phantom perceptions.”
Watch the video below for a summary of the study:
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“Hallucinations” are when our brains trick us into thinking we’re seeing, hearing, feeling, or smelling something that’s not physically there.
Many people experience hallucinatory perceptions only during sleep, but for about 15% of the world’s population, the inevitable noises also ring in their ears while awake.
Tinnitus is the most common hallucination in the world, and although there are many hypotheses, there is no known cause or cure.
Although many people with tinnitus report poor sleep quality and exhibit adverse sleep patterns, potential links to this important body function have only recently been discovered.
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In 2022, Milinski led a review that the authors claimed was the first to functionally consider how sleep affects tinnitus and vice versa.
Researchers at the University of Oxford suggest that the large waves of spontaneous brain activity that occur during deep sleep, or non-rapid eye movement sleep (non-rapid eye movement sleep), may suppress the brain activity that causes tinnitus.
To test this idea, the team turned to ferrets, whose auditory systems are similar to those of humans. In experiments published in 2024, researchers found that ferrets with more severe tinnitus also experienced disrupted sleep.
“We can actually see these sleep problems co-occur with tinnitus after noise exposure,” Milinski told ScienceAlert. “This is the first time that there is a clear link between tinnitus and sleep disruption.”
Crucially, ferrets with tinnitus showed brain activity that was hypersensitive to sound. When the ferrets finally manage to enter non-rapid eye movement sleep, this hyperactivity is suppressed.
This suggests that sleep may temporarily mask the effects of tinnitus by engaging the same brain circuits.
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“Our findings suggest that deep sleep may indeed help alleviate tinnitus and may reveal natural brain mechanisms that regulate abnormal activity,” Milinski said.
Research on non-human animals has its obvious limitations, but the same brain activity patterns may exist in humans as well.
Milinski said the field has expanded rapidly since the 2022 review, with an increasing number of large-scale studies investigating how sleep, environment and tinnitus interact, and not just in ferrets.
“I hope this study will increase awareness of tinnitus and open up new ways to explore treatments,” Milinski told ScienceAlert.
“It’s important to acknowledge the impact of tinnitus, especially in older people, as hearing loss and tinnitus can increase feelings of isolation and lead to mental health problems.”
Just last year, a study out of China found that people with tinnitus were less able to suppress overactivity in their waking brains when they fell asleep.
However, during deep sleep, tinnitus-related hyperactivity is suppressed.
“This study identifies sleep as a key therapeutic target for interrupting the dysfunctional 24-hour cycle of tinnitus,” concluded the authors, led by Xiaoyu Bao of South China University of Technology.
At the University of Oxford, Milinski and colleagues are now focusing on how sleep affects the development of tinnitus.
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“Tinnitus can make sleep worse, and poor sleep can, in turn, make tinnitus worse. It’s probably a vicious cycle, although I don’t believe it’s unbreakable,” Milinski speculates.
“When we don’t sleep well, we are more susceptible to the effects of stress, which is one of the strongest factors known to worsen tinnitus. Stress can even trigger tinnitus.”
Further research could not only lead to effective tinnitus treatments, but also help scientists better understand the mysteries of sleep itself.
2022 review published in brain communication.
An earlier version of this article was published in November 2025.