fMRI Brain Responses in Misophonia vs Hyperacusis

A new brain imaging study directly compared the neural signatures of misophonia and hyperacusis, revealing both distinct and overlapping patterns. Published in Cognitive, Affective, & Behavioral Neuroscience, the research by Namitha Jain, Shagun Ajmera, Somayeh Shahsavarani, and colleagues at the University of Illinois Urbana-Champaign clarifies how these often-confused sound tolerance disorders differ in the brain.

Mapping Sound Sensitivity in the Brain

The researchers recruited 91 young adults and categorized them into four groups: those with misophonia, those with hyperacusis, those with both conditions (comorbid), and a control group with no sound sensitivities. All participants underwent functional magnetic resonance imaging (fMRI) while listening to 90 emotionally valenced sounds from a standardized database. The sounds ranged from pleasant to neutral to unpleasant. During the scan, participants rated how pleasant or unpleasant each sound was.

This task-based fMRI approach allowed the team to observe real-time brain activation and, more importantly, the functional connectivity between different brain networks during sound processing. The study’s design directly addressed a persistent challenge in the field: misophonia and hyperacusis share symptoms and often co-occur, making clear differentiation difficult. A separate fMRI study on this topic also highlights the importance of such direct comparisons.

Misophonia Involves the Visual Brain

One of the most striking findings centered on misophonia. Individuals with misophonia, regardless of whether they also had hyperacusis, showed heightened activation in visual association areas of the brain when listening to unpleasant sounds versus neutral ones. Furthermore, they exhibited reduced connectivity between the brain’s salience network—which flags important stimuli—and these visual networks.

“This suggests atypical cross-modal sensory involvement,” the authors wrote. In simpler terms, the brains of people with misophonia may be involuntarily recruiting visual processing regions when triggered by a sound. This could relate to the intense, often visual, mental imagery (like imagining the source of the chewing sound) that many with misophonia report. It points to misophonia as a condition where the brain’s response to specific trigger sounds spills over into other sensory systems.

Hyperacusis Shows Impaired Top-Down Control

The neural pattern for hyperacusis was different. This group showed reduced connectivity between key hubs of the salience network and regions in the frontal cortex responsible for top-down executive control. Compared to both controls and the misophonia group, this weakened link was pronounced.

This finding indicates that hyperacusis may involve a breakdown in the brain’s ability to regulate and modulate its reaction to sounds deemed too loud or intense. The frontal cortex helps dampen reactions; a poor connection to the salience network suggests this damping mechanism is impaired. The misophonia group, in contrast, preserved this particular connectivity for generally unpleasant sounds, indicating their top-down regulation for non-specific triggers is intact. This aligns with other research on brain changes in hyperacusis that point to regulatory dysfunction.

The Comorbid Group Shows a Combined Pattern

Participants who had both misophonia and hyperacusis displayed neural features associated with each disorder. Their brain activity and connectivity patterns were not simply an average of the two, but showed evidence of both the cross-modal visual involvement seen in misophonia and the impaired frontal regulation seen in hyperacusis. This provides strong evidence that while these conditions overlap clinically, they have separable neural underpinnings that can co-exist in one individual.

Implications for Diagnosis and Future Treatments

These findings have direct practical implications. For diagnosis, the study supports the use of behavioral questionnaires that carefully distinguish between sound-triggered anger or disgust (common in misophonia) and physical pain or fear of loudness (common in hyperacusis). The distinct brain patterns confirm these are different experiences with different neural roots.

For treatment, the research suggests different targets. Interventions for misophonia might benefit from considering its multisensory nature, potentially incorporating techniques that address the intrusive visual component or the learned associative response. Therapies for hyperacusis might focus more on strengthening top-down cognitive control and emotional regulation networks, similar to approaches used for some forms of tinnitus that involve limbic system changes.

The authors conclude that future work should combine this type of neural data with detailed behavioral measures to build better models of these disorders. “Future research should combine neural and behavioral data to refine mechanistic models and guide targeted interventions,” they write. This precision is essential, as blanket approaches for “sound sensitivity” are unlikely to be effective for all.

The study, “Differential brain responses to affective sounds in misophonia and hyperacusis: A task-based fMRI approach” (DOI: 10.3758/s13415-026-01435-z, PMID: 41981382), moves the field beyond symptom checklists and into the biology of distress, offering a clearer path toward personalized management strategies.