We spend our days inundated by sounds — both pleasant and irksome — arising from the physical environment. This ubiquitous clatter is more than just distracting: It can lead to cognitive dysfunction. But rather than blocking out the cacophony with headphones or earbuds delivering your favorite tunes, you might be doing your brain a favor by seeking out some silence.
Recent research suggests that extended periods of quiet can generate new brain cells while also reducing levels of stress hormones in the body. “Silence can quite literally grow your brain,” says Duke University Medical Center researcher Imke Kirste, PhD.
Her 2013 study on mice suggests that two hours of silence per day produces new functioning neurons in the hippocampus, the area of the brain associated with memory, emotion, and learning. Quiet time, Kirste found, may allow the brain to process information more efficiently.
Earlier research reported that children whose homes or schools are located beneath airline flight paths or near highways and railways tend to develop language and other cognitive skills more slowly than kids in quieter areas. That could be due to the way the brain reacts to sound: The amygdala may respond to noise by triggering a cascade of stress hormones that can hinder a child’s ability to absorb information.
After officials in Munich, Germany, relocated the city’s major airport, Gary Evans, PhD, and a team of Cornell University scientists studied the impact of its noise pollution on children living nearby. Their report, published in Psychological Science, notes that the constant roar emanating from the facility produced elevated levels of cortisol and other stress hormones in the young study participants.
This stress response, which initially served to block out the airport sounds, eventually made it more difficult for the kids to pay attention to ordinary speech.
“This study is among the strongest, probably the most definitive proof that noise — even at levels that do not produce any hearing damage — causes stress and is harmful to humans,” says Evans.
It’s not only children who suffer from too much racket in their lives. Multiple studies show that adults exposed to chronic noise pollution may experience foggy memory, reduced attention span, and other problem-solving issues.
Regular periods of silence may allow your brain to relax its sensory response and recover the cognitive function eroded by too much noise.
If two hours a day seems out of reach, simply try to slip away to a quiet place for a few minutes whenever you can. You may find the lack of sound more intriguing than anything your earbuds can offer.