Summary: For people with chronic back pain, a slamming door or a loud TV isn’t just annoying—it actually feels physically harsher. A new study reveals that chronic pain triggers a “sensory amplification” in the brain that extends far beyond the back. By using fMRI scans, researchers found that the brains of chronic pain patients react more intensely to everyday sounds than 84% of healthy individuals.
Most importantly, the study proved that this “volume knob” in the brain can be turned back down through Pain Reprocessing Therapy (PRT), which retrains the brain to stop over-reacting to sensory signals.
Key Facts
- Sensory Overload: People with chronic back pain process sounds more intensely, particularly in the auditory cortex and the insula (the brain’s emotional processing center).
- The “Brake” Failure: Scans showed lower activity in the medial prefrontal cortex, the region responsible for calming down emotional reactions to unpleasant sensations.
- Beyond the Back: The findings prove that chronic pain is a whole-brain phenomenon. The brain effectively “turns up the volume” on all sensory inputs, not just signals from the spine.
- PRT Success: Pain Reprocessing Therapy was found to be the most effective treatment, not only reducing pain but also physically normalizing the brain’s response to sound.
- Pre-existing Vulnerability: Researchers suspect that people who are naturally more sensitive to light, sound, or smell may be at a higher risk of developing chronic pain after an injury.
Source: University of Colorado
People with chronic back pain process everyday sounds differently, and more intensely, than people without pain, according to new research from the University of Colorado Anschutz.
Published today in Annals of Neurology, the study is one of the first to tie this sound hypersensitivity to specific, measurable changes in the brain, indicating that chronic back pain affects far more than the back. The research also shows there’s an effective treatment that can help.
“Our findings validate what many patients have been saying for years that everyday sounds genuinely feel harsher and more intense. Their brains are responding differently, in regions that process both the loudness of sound and its emotional impact. This tells us chronic back pain isn’t just about the back.
“There’s a broader sensory amplification happening in the brain, and that opens the door for treatments that can help turn that volume down,” said the paper’s senior author Yoni Ashar, PhD, assistant professor of internal medicine and co-director of the Pain Science Program at the University of Colorado Anschutz School of Medicine.
The researchers compared self-reported and neural responses in 142 adults with chronic back pain relative to 51 pain-free controls. All participants, including controls, underwent brain imaging.
During the MRI session, the researchers had participants do several tasks, such as listen to sounds while the researchers asked participants how unpleasant the sounds felt and measured how strongly key brain regions responded.
The differences between chronic pain patients and healthy controls were large. The researchers found on average, they reacted more strongly than 84% of people without pain.
The also found in the scans that changes were not happening in the initial auditory processing areas but were happening higher up in the brain. In particular, the scans showed stronger responses in regions that process sound (the auditory cortex) and emotional sensations (the insula). At the same time, they saw lower activity in brain regions that normally help calm or regulate reactions, like the medial prefrontal cortex.
The researchers also looked at treatment options and assigned participants with chronic back pain to one of three groups:
- Pain Reprocessing Therapy (PRT) – therapy sessions designed to help people reinterpret pain as due to brain amplification rather than just back problems.
- Placebo treatment – a saline injection delivered within a supportive, clinical setting.
- Usual care – participants continued whatever treatments they were already using.
They found that out of all the treatments, Pain Reprocessing Therapy was the most effective. It not only reduced the heightened brain response to sound but also increased activity in brain regions involved in regulating unpleasant experiences.
“This shows that the brain’s exaggerated sensory response can improve with psychological treatment so instead of being something patients are stuck with, this sensitivity is treatable,” said Ashar.
“These findings add to growing evidence that chronic back pain is not just a problem in the back, the brain plays a central role in driving chronic pain, by amplifying a range of sensations – sensory signals from the back, sounds, and likely other sensations as well.”
Past research from Ashar found that Pain Reprocessing Therapy led two thirds of participants with chronic back pain to become pain‑free or nearly so after treatment, far outperforming the roughly 20% improvement seen in the placebo group.
The research also raises several important questions, including whether this heightened sensitivity is a cause of chronic back pain or a pre‑existing vulnerability to develop chronic pain.
Early evidence from other groups suggests that people who are naturally more sensitive to sensory input may be more likely to develop chronic pain after an injury. It also remains unclear whether the amplification extends to other senses, such as light, smell or taste, or whether this happens with other chronic pain conditions.
They say their next study will test sensitivity across additional senses to determine how widespread this amplification truly is, and whether one central brain regions may be responsible for this amplification across the senses.
Key Questions Answered:
A: Chronic pain puts your brain in a state of high alert. To protect you, the brain “turns up the gain” on all incoming signals so it doesn’t miss anything important. Unfortunately, this means everyday sounds—like a vacuum or a siren—start to feel painful or overwhelming.
A: Yes! The study showed that Pain Reprocessing Therapy (PRT) helps the brain re-categorize these signals. By teaching the brain that these sensations aren’t dangerous, the “volume” naturally starts to decrease, making both your back and your ears feel better.
A: No. This is a measurable, biological change in the brain’s wiring. It’s not about your mood; it’s about how your auditory cortex and emotional centers are physically firing in response to sound waves.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by our staff.
About this pain and auditory neuroscience research news
Author: Julia Milzer
Source: University of Colorado
Contact: Julia Milzer – University of Colorado
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Auditory Hyperresponsivity in Chronic Back Pain: A Randomized Controlled Trial of Pain Reprocessing Therapy” by Alina E. C. Panzel MSc, Christian Büchel MD, Andrew Leroux PhD, Tor D. Wager PhD, Yoni K. Ashar PhD. Annals of Neurology
DOI:10.1002/ana.78183
Abstract
Auditory Hyperresponsivity in Chronic Back Pain: A Randomized Controlled Trial of Pain Reprocessing Therapy
Objective
Heightened sensitivity to noxious stimulation is a hallmark of chronic pain. Emerging evidence suggests heightened unpleasantness to non-noxious (eg, auditory) aversive stimulation also characterizes chronic pain, but its magnitude, neural mechanisms, and treatment modifiability remain unknown.
Methods
We compared behavioral and neural responses to auditory and pressure stimulation in 142 adults with chronic back pain (CBP) relative to 51 pain-free controls. CBP patients then entered a randomized trial of pain reprocessing therapy (PRT) versus placebo and usual care. During functional magnetic resonance imaging, participants experienced low- and high-intensity aversive sounds and mechanical pressure and provided unpleasantness ratings.
Univariate analyses examined responses in primary sensory, sensory-integrative, and midline default mode network regions. Multivariate analyses tested 4 a priori whole-brain patterns, including patterns predictive of fibromyalgia.
Results
CBP patients versus healthy controls reported heightened unpleasantness to auditory stimuli (Hedges’ g = 0.95–1.03; p < 0.001) and mechanical pressure (g = 0.49–0.66; p < 0.001). For patients versus controls, auditory stimulation revealed hyperresponsivity in primary auditory cortex and insula, hyporesponsivity in the precuneus and medial prefrontal cortex (g = 0.33–0.59, p < 0.05), and increased expression of generalized and auditory-specific aversive processing patterns (g = 0.33–0.39, p < 0.05) and of fibromyalgia-derived multisensory sensitivity patterns (g = 0.43–0.50, p < 0.01). Longitudinal analysis found that PRT versus placebo led to reduced unpleasantness of low-intensity auditory stimulation, along with increased medial prefrontal cortex responses for PRT versus usual care.
Interpretation
CBP is associated with pronounced auditory hyperresponsivity via modality-specific and modality-general neural pathways, and brain mechanisms overlap with fibromyalgia. PRT versus control produced small reductions in this hyperresponsivity, suggesting potential for PRT to yield broader “central desensitization”.
