Misophonia vs Hyperacusis: fMRI Brain Response Study

A new fMRI study of 91 young adults has identified distinct brain activity patterns that differentiate misophonia from hyperacusis, two often-confused sound tolerance disorders. The research, led by Dr. Namitha Jain and Dr. Fatima T. Husain at the University of Illinois Urbana-Champaign, shows that while these conditions share symptoms, their neural mechanisms are not the same.

Mapping Brain Responses to Emotional Sounds

The research team recruited participants and categorized them into four groups: those with misophonia, those with hyperacusis, those with both conditions (comorbid), and a control group with typical sound tolerance. Using task-based functional magnetic resonance imaging (fMRI), the scientists measured brain activity while participants listened to 90 emotionally valenced sounds from a standardized database. The sounds ranged from unpleasant (like screams) to pleasant and neutral. During scanning, participants rated how positive or negative each sound felt.

This method allowed the researchers to observe real-time brain activation and, critically, to analyze functional connectivity. Connectivity measures how well different brain regions communicate with each other during a task, providing insight into neural networks that might function differently in each disorder.

Misophonia Shows Atypical Cross-Mensory Involvement

The brain scans revealed a clear signature for misophonia. Individuals with misophonia, including those who also had hyperacusis, showed heightened activation in visual association areas of the brain when processing unpleasant versus neutral sounds. This was an unexpected finding, as the task involved only auditory stimuli.

Further analysis of brain network communication found reduced connectivity between the salience network—which identifies important stimuli—and visual networks in the misophonia group. “This suggests atypical cross-modal sensory involvement,” the authors note in the paper published in Cognitive, Affective, & Behavioral Neuroscience. In simpler terms, the brains of people with misophonia may be involuntarily recruiting visual processing resources when hearing trigger sounds, which could relate to the intense, often visual, imagery or context that accompanies reactions to sounds like chewing or breathing. This aligns with patient reports where the sight of a trigger action worsens the sound’s impact.

Hyperacusis Points to Impaired Top-Down Control

In contrast, the neural pattern for hyperacusis was different. The group with hyperacusis alone exhibited reduced connectivity between key hubs of the salience network and frontal control regions in the brain. The frontal cortex is responsible for top-down regulation, such as modulating attention and emotional responses.

This weakened link indicates that for people with hyperacusis, the brain’s system for flagging a sound as salient or important may not be effectively regulated by its control centers. This could explain the physical discomfort and pain response to sound volume or intensity, representing a failure to dampen the perceived threat of generally loud sounds. Notably, this regulatory connectivity was preserved in the misophonia group for broadly unpleasant sounds, indicating their difficulty is more specific than a general regulatory failure.

The Comorbid Group Reflects a Combined Profile

Participants who had both misophonia and hyperacusis presented a neural profile that incorporated elements of both disorders. Their brain activity and connectivity patterns showed the visual-area hyperactivation seen in misophonia alongside the impaired salience-control connectivity seen in hyperacusis. This finding is vital clinically, as it demonstrates that comorbidity is not just a more severe version of one disorder but a distinct combination with its own neural basis. It helps explain why individuals with both conditions can experience both specific trigger-based reactions and general loudness intolerance.

Implications for Diagnosis and Future Treatment

These findings have direct practical implications. The overlap in symptoms—distress to sound—often leads to misdiagnosis or conflation of misophonia and hyperacusis. This study provides objective neural evidence that they are different conditions with different brain mechanisms. This knowledge can move diagnosis beyond subjective questionnaires toward more nuanced profiles.

For treatment, the paths may diverge. Interventions for misophonia, as suggested by the cross-modal visual involvement, might benefit from techniques that address multisensory integration or contextual associations. A related article on our site, “Misophonia vs Hyperacusis: Brain fMRI Differences”, explores this further. For hyperacusis, treatments aimed at strengthening top-down cognitive control or recalibrating the salience of sound intensity could be more effective. The research also underscores the need for combined strategies for those with comorbid conditions.

This study adds to a growing body of work using neuroimaging to understand hearing-related disorders. For instance, similar techniques have been used to explore neural signatures in tinnitus and hyperacusis and the general brain’s response to sound.

The authors conclude that future research should combine this neural data with detailed behavioral measures to build precise models of these disorders. This will be essential for developing targeted interventions, whether therapeutic or technological, that address the specific brain dysfunctions identified.

Source: Jain N, Ajmera S, Shahsavarani S, et al. Differential brain responses to affective sounds in misophonia and hyperacusis: A task-based fMRI approach. Cogn Affect Behav Neurosci (2026). doi:10.3758/s13415-026-01435-z. PMID: 41981382.