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For years, population studies have shown that untreated hearing loss is associated with a higher risk of cognitive decline and dementia—enough that the 2024 Lancet Commission continues to list hearing loss among the most impactful modifiable dementia risk factors. What’s been harder to understand is the biological “bridge” between the ears and the brain.
A new paper in eNeuro from researchers at Tiangong University and Shandong Provincial Hospital (China) proposes one candidate bridge: a Functional-Structural Ratio (FSR) derived from MRI measures of brain activity and gray-matter volume. The team reports that lower FSR in a handful of brain regions correlates with worse hearing, poorer speech recognition, and lower cognitive test performance in adults with presbycusis (age-related hearing loss).
The study involved 55 adults with presbycusis (24 men, 31 women) and 55 age-matched healthy controls (23 men, 32 women). Participants were 50-74 years old, and the presbycusis group included mostly people with mild or moderate hearing loss.
The 55 adults with age-related hearing loss (presbycusis) were compared to the 55 similar adults with normal hearing. Everyone took standard hearing tests and a few brief thinking and memory tests, then had an MRI brain scan. From the scans, the team looked at two things in specific brain areas: how active brain regions seemed at rest and how much gray matter they had. They combined those measures into a single ratio (the FSR) which is meant to reflect how well brain function and brain structures line up.
The main takeaway: across several brain regions involved in sound/speech processing and higher-level thinking, people with presbycusis tended to show a weaker match between structure and function. Poorer hearing and speech understanding went along with more substantial changes in these brain measures, and those same changes also tracked with lower scores on memory and attention-type tests.
The authors argue that presbycusis might involve a coordinated decline in both brain structure and function, not just an “ear problem,” and that FSR could eventually be useful for screening or monitoring presbycusis-related cognitive risk.
“The most important takeaway is that preserving hearing health may protect brain integrity,” said lead author Ning Li in the Society for Neuroscience press release. “Because changes in the FSR correlate with both hearing loss and cognitive decline, this ratio could eventually serve as a biomarker—a tool for doctors to identify who is at the highest risk for dementia simply by looking at their brain scans.”
This study, along with others, also hints at a more holistic outlook in hearing healthcare. For example, in a 2021 review, Glick & Sharma summarized EEG-based work showing that adults with mild-to-moderate age-related hearing loss can exhibit cross-modal recruitment and frontal involvement, and that greater reorganization tends to track with poorer speech-in-noise performance and weaker cognition. Additionally, the study found evidence that well-fit hearing aids over months might reduce or reverse some of that cross-modal recruitment while improving speech-in-noise and several cognitive measures. This appears to align with the new eNeuro paper’s findings: hearing loss is associated with measurable brain reorganization that extends beyond classic auditory pathways and may be linked to cognition.
Because of the eNeuro study's methods and small number of participants—one set of tests and one MRI scan at a single point in time for 55 participants—no firm conclusions can be made. The results show associations, but they cannot prove whether hearing loss causes the brain changes, whether earlier brain changes contribute to both hearing and cognitive performance, or if some other factor influences all of them. Using Functional-Structural Ratio (FSR) data is interesting, but it still needs to be validated in larger, more diverse groups and tested to see whether it can predict future cognitive decline (not just correlate with current test scores), and whether it’s stable and useful at the individual patient level.
Even so, the new study does suggest a specific, testable brain-based link between hearing measures and cognitive performance, supporting the broader view that hearing health can be relevant to brain health. If future research validates FSR as a reliable marker, it could help researchers or even clinicians identify people with presbycusis who are on a steeper brain-health trajectory and recommend interventions that improve hearing and communication, helping stabilize the underlying brain-network changes.
SOURCE: Li, Fu, Wang, et al. and EurekAlert
Original paper: Li X, Fu W, Wang F, et al. Functional-structural coupling: Brain reorganization in presbycusis is related to cognitive impairment. eNeuro. 2026 (Feb 16); DOI:10.1523/ENEURO.0294-25.2026
Karl Strom ist der Chefredakteur von HearingTracker. Er war Gründungsredakteur von The Hearing Review und berichtet seit über 30 Jahren über die Hörhilfenindustrie.
