New Science May Show Why Sound Can Ease Pain
Aug. 26, 2022 – Listen up, everybody: If you’ve ever thought your favorite song made your whole body feel better, new science suggests that wasn’t just your imagination.
In fact, it’s not only music that has an analgesic, or pain-reducing, effect. Many types of sounds or noises can help, researchers have found – if they’re played at the right volume, that is.
Doctors and researchers have long known about a connection between sound and the body. Music therapy has been used for decades to help manage pain after an operation, during labor and after childbirth, and during cancer treatment.
But why this happens isn’t well understood. Some theories suggest the analgesic effects of sound are psychological – that is, they calm, or distract, a person from the pain.
This new research suggests that something deeper is at work. And the paper, published in Science, may shed light on the inner workings of the brain, revealing the circuitry operating behind this pain relief.
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Yuanyuan (Kevin) Liu, PhD, is a sensory biology and pain researcher for the National Institute of Dental and Craniofacial Research and a co-author of the study.
“Relative sound intensity might play a role in helping reduce pain,” he says. “Low-intensity sound is able to inactivate the audio-somatosensory pathway and thus the activation of the somatosensory thalamus.” That means a noise played at low volume appears to blunt activity in parts of the brain responsible for signaling pain.
In the study, scientists injected mice with a solution that caused discomfort in their paw. They then put on a variety of sounds at different intensities, ranging from pleasant music to white noise, and watched for any changes in the rodents’ behavior.
What they saw, according to Liu, suggested that the sounds “reduced reflexive paw withdrawal and aversion to painful stimuli – indicators of analgesia for rodents.” In other words, the sounds appeared to help reduce pain in the mice.
The ideal volume for pain relief was just 5 decibels above room noise, the researchers found.
“The 5-decibel low-intensity sound is related to the background sound,” Liu explains. “It is not an absolute but rather a relative value.” So, you’d want to raise the volume just a bit louder than the background noise wherever you are.
And in what might be good news for sludge metal fans, the types of sound played made no difference. Even when noises were adjusted to be “unpleasant,” playing them at the right volume still provided a pain-relieving effect.
It doesn’t matter whether you’re into Mozart or Metallica, according to the findings, at least. Either can work – so long as the tunes are played at the right volume.
The Future of Sound and Pain Management
Liu cautions that when it comes to transcribing the symphony of how body and mind respond to sound, we’re only in the opening measures.
“There’s still a long way to translate these findings in mice to the human context,” he says.
We can’t say for sure that human brains work the same as mouse brains when exposed to sound. But the findings in mice can offer clues about how our brains might operate – and therefore provide us with one piece of the puzzle in understanding how sound influences the perception of pain.
“We hope our study opens up new directions for the field of sound-induced analgesia,” Liu says. But much more research needs to be done for that to happen.