Research from the University of Oxford suggests a significant connection between tinnitus and sleep, offering new insights into these often debilitating conditions. Neuroscientists believe that understanding this relationship could pave the way for better treatments for tinnitus, a condition characterized by persistent ringing or other phantom sounds in the ears.
Neuroscientist Linus Milinski, part of Oxford’s Sleep and Circadian Neuroscience Institute, noted, “What first made me and my colleagues curious were the remarkable parallels between tinnitus and sleep.” Tinnitus affects approximately 15 percent of the global population, yet no effective treatment currently exists. This research may change that by exploring how spontaneous brain activity during sleep influences tinnitus.
Milinski’s team conducted a thorough review in 2022, which examined the functional relationship between sleep and tinnitus for the first time. They proposed that large spontaneous brain waves during deep sleep, also known as non-rapid eye movement (non-REM) sleep, might suppress the brain activity associated with tinnitus.
To investigate this hypothesis, the researchers turned to ferrets, whose auditory systems closely resemble those of humans. In experiments published in 2024, they found that ferrets experiencing stronger tinnitus also displayed disrupted sleep patterns. “We could actually see these sleep problems appear at the same time as tinnitus after noise exposure,” Milinski explained.
The findings indicated that ferrets with tinnitus exhibited heightened brain responsiveness to sound. When they were able to enter non-REM sleep, this hyperactivity diminished, suggesting that deep sleep could temporarily mitigate tinnitus by engaging similar brain circuits.
“Our findings indicate that deep sleep may indeed help mitigate tinnitus and could reveal natural brain mechanisms for modulating abnormal activity,”
Milinski stated.
While animal studies have limitations, the patterns observed in ferrets may hold true for humans as well. Following the 2022 review, the field has expanded, with more large-scale studies emerging to explore the interaction between sleep, tinnitus, and environmental factors. “I hope this research will lead to greater awareness of tinnitus and open new ways of exploring treatments,” Milinski added.
A recent study from South China University of Technology, led by Xiaoyu Bao, supports this view, indicating that individuals with tinnitus struggle to suppress hyperactive brain activity as they transition into sleep. However, during deep sleep, the hyperactivity associated with tinnitus was notably reduced. “This study establishes sleep as a critical therapeutic target to interrupt the 24-hour dysfunctional cycle of tinnitus,” the authors concluded.
Milinski and his colleagues are now investigating how sleep influences the onset of tinnitus. They suggest that the relationship is cyclical: tinnitus can disrupt sleep, and poor sleep quality may exacerbate tinnitus. “When we do not sleep well, we become more vulnerable to stress, and stress is one of the strongest factors known to worsen tinnitus,” Milinski said.
Future research could not only lead to effective treatments for tinnitus but also deepen the understanding of sleep mechanisms. The insights gained from this ongoing research may significantly impact how both conditions are perceived and treated in clinical settings. The initial findings from the 2022 review were published in the journal Brain Communications, emphasizing the importance of this emerging field.
