A study by the Center for Regenerative Therapies in Dresden suggests what every parent with children who scream all the time knows: silence repairs and heals. An experiment conducted on mice suggests that brief periods of silence can activate precursor cells. After a week, new neurons in the hippocampus may also increase. In the end, it turns out that you need a little peace and quiet every day.
Experiment on mice: noise vs. silence
They discovered that almost all auditory stimuli increased the proliferation of precursors in just 24 hours. However, only silence maintained an increase in new neurons after seven days. All of this is concentrated in the hippocampus, which is the part of the brain key to memory and learning. Although this result has been found in mice, it is still under debate how applicable it is to humans.
In mammals, the adult hippocampus can generate new neurons; as we have said, it is associated with memory, cognitive flexibility, and resilience to stress. In humans, there are already studies that demonstrate neurogenesis in healthy adults, while other studies consider it to be very rare; for now, the debate remains open. The scientists who conducted the study believe that unusual silence could activate alert circuits, generating a nonspecific signal that recruits precursors (“listening to nothing” was, until 100 years ago, normal for a human being not surrounded by technology).
Why does reducing noise help?
It has always been said that noise “dulls the senses,” and science backs this up. Exposure to intense or chronic noise is associated with reduced hippocampal neurogenesis, impaired spatial memory, and increased stress hormones in animals. There are also links to cognitive decline in humans. In addition, noise-induced hearing loss also impairs hippocampal function and causes inflammation and oxidative stress in the body.
What we do know for sure is that the sound environment modulates the brain; silence is a good tool for promoting neural rest, internal tension, and brain plasticity. But it is not yet certain that a few minutes of silence directly increase neurogenesis as measured by biomarkers, but I don’t think seeking out moments of silence throughout the day can do any harm either.
How can you find silence in everyday life?
Daily life in the West can be extremely noisy: podcasts, music at all hours, noisy neighbors, traffic, construction noise, etc. If you want a little peace, you’ll have to focus on what you can control. In other words, turn off stimuli. Try spending some time without music or podcasts, sit with your eyes closed, and try to breathe calmly. To do this, you can find the quietest room in your house or use noise-canceling headphones (without audio, of course).
If you have to commute every day, for example to work, try not to use headphones. Often when we are overwhelmed, we need silence to hear our own inner voice and process our emotions and thoughts. Keep in mind that for most of human history, people have had many hours of silence and introspection. Being surrounded by noise and stimuli is a very recent phenomenon.
Another way to use silence as a tool is to spend a minute or two in silence after learning an important concept; this will ensure that we internalize this knowledge properly before moving on to something else. We also recommend spending at least 20 minutes without screens or sound before going to sleep; according to the general principle of stress and plasticity, any high stress (such as watching the news on your cell phone) will disrupt your circadian cycle and cause insomnia.
Needless to say, a very effective way to use silence as a healing tool is to escape from urban centers and spend time in rural environments such as parks and forests. The soft sounds of nature act as a structured, undemanding stimulus, connecting us to the true environment in which we have evolved as a species.