August 26, 2022 – Everyone listen: If you’ve ever thought your favorite song made your whole body feel better, new scientific evidence suggests it wasn’t just your imagination.
In fact, not only music has an analgesic or pain-relieving effect. Researchers have found that many types of tones or noises can help – if played at the right volume.
Physicians and researchers have known for a long time about the connection between sound and the body. Music therapy has been used for decades to relieve pain after surgery, during labor and childbirth, and during cancer treatment.
but why what happens is not well understood. Some theories suggest that the analgesic effects of sound are psychological—that is, they calm or distract a person from pain.
This new research suggests something deeper is at work. And the paper, published in Science, can shed light on the inner workings of the brain and reveal the circuits that operate behind this pain relief.
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Yuanyuan (Kevin) Liu, PhD, is a sensory biologist and pain researcher at the National Institute of Dental and Craniofacial Research and a co-author of the study.
“The relative sound intensity could play a role in pain relief,” he says. “Low-intensity sound is able to inactivate the audio-somatosensory pathway and thus activation of the somatosensory thalamus.” This means that a sound played at low volume appears to dampen activity in parts of the brain that are responsible for signaling pain.
In the study, scientists injected mice with a solution that caused discomfort in their paw. They then applied different sounds of varying intensities, ranging from pleasant music to white noise, and observed whether the rodents’ behavior changed.
According to Liu, what they saw suggested that the sounds “reduced reflexive paw withdrawal and aversion to painful stimuli — indicators of analgesia in rodents.” In other words, the sounds seemed 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 noise,” Liu explains. “It’s not an absolute value, it’s a relative value.” So you should turn up the volume a little louder than the background noise, wherever you are.
And what could be good news for sludge metal fans, the type of sound played made no difference. Even when sounds were set as “uncomfortable,” playing at the right volume still had a pain-relieving effect.
It doesn’t matter whether you like Mozart or Metallica, at least according to the findings. Both can work – as long as the melodies are played at the right volume.
The future of sound and pain treatment
Liu warns that when transcribing the symphony, we are only in the opening bars of how the body and mind respond to sounds.
“There is still a long way to go before these results in mice can be extrapolated to humans,” he says.
We cannot say with certainty that human brains function the same as mouse brains when exposed to sound. But the results in mice may provide clues as to how our brains might work – and therefore provide us with a piece of the puzzle to understand how sound affects pain perception.
“We hope that our study will open up new directions in the field of sound-induced analgesia,” says Liu. But much more research needs to be done for this.