In this day and age, we’d be hard-pressed to find a few moments without the cacophony of modern life swirling around us. With 24/7 access to television, streaming video, radio and all sorts of digital music, we might not give a second thought to the constant audio bombardment.
Nor do we typically notice the day-to-day chatter from our coworkers, friends and families. Then there’s the constant buzz of lawnmowers, highways, trains, planes and automobiles. But science is finding that “noise pollution” may very well dumb us down, compromise health and dramatically increase stress and the accompanying hormones — unfortunately, this last bit can lead to weight-gain and heart disease. Even low levels of noise can trigger a cascade of undesirable effects. It’s enough to drive one mad — literally.
In a world where noise is a given and rarely a choice, silence sells because it’s so uncommon. Finland has built a tourist industry around it by marketing silence as a resource, with catchy country branding like “Silence, Please” and “No talking, but action.” Finnish watch maker Rönkkö has also taken up the torch by proclaiming their products are “Handmade in Finnish silence.” In the quest for ever elusive quiet, people will shell out hundreds of dollars for noise-canceling headphones or pay into the thousands for silent meditation retreats. Beyond simply being a rare commodity, scientists are proving what we already know on an intuitive level — periods of silence are good for the body, mind and soul. But it’s only recently been discovered how crucial peace and quiet really is for our well-being.
A clamorous world is an unhealthy one
The translation for the Latin root “noise” is nausea or pain — which is exactly what happens when we are exposed to loud environments, especially if we are sensitive to sound to begin with. When noise becomes a chronic problem, our health ultimately suffers.
Writes Daniel A. Gross in This Is Your Brain on Silence:
“Studies of human physiology help explain how an invisible phenomenon can have such a pronounced physical effect. Sound waves vibrate the bones of the ear, which transmit movement to the snail-shaped cochlea. The cochlea converts physical vibrations into electrical signals that the brain receives. The body reacts immediately and powerfully to these signals, even in the middle of deep sleep. Neurophysiological research suggests that noises first activate the amygdalae, clusters of neurons located in the temporal lobes of the brain, associated with memory formation and emotion. The activation prompts an immediate release of stress hormones like cortisol. People who live in consistently loud environments often experience chronically elevated levels of stress hormones.”
These stress hormones have a real impact on health by encouraging high blood pressure, insomnia, heart disease and obesity. Our escalating noise levels have become such a problem that the World Health Organization reported in 2011 that western Europe (population 340 million) annually lost the equivalent of a million years worth of healthy life because of noise. The WHO also noted that 3,000 deaths due to heart disease were linked with exposure to excessive noise.
Further research published in the journal Psychological Science investigated how the relocation of Munich’s airport affected children’s health and learning. Gary W. Evans of Cornell University found that the children developed a stress response which helped them to ignore the noise, but they also ignored other stimuli as well — such as speech. The children tended to block out a majority of stimuli when exposed to loud noise, even areas where they should have been paying attention.
“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,” said Evans.
Additional research supports these findings. Noise pollution has been found to negatively impact cognitive task performance like reading attention, problem solving, language skill and memory. Children who live in households or attend schools near railways, flight paths or highways are particularly at risk.
While noisy environments damage our health, the opposite is true of silent spaces. A study published in the journal Brain, Structure and Function measured the effects different types of noise and periods of silence had on test mice. The silent periods were meant to function as the control, but a surprising development occured. When the mice were exposed to two hours of silence per day, the animals actually grew new cells in the hippocampus region of the brain — an area connected to memory, emotion and learning.
Imke Kirste, a regenerative biologist at Duke University and one of the lead researchers, believes that, due to the total absence of sound, the environment was so artificial — and possibly alarming — that the mice were on high alert, and subsequently created the new cells. What’s interesting about this development is that the cells appeared to turn into functioning neurons. “We saw that silence is really helping the new generated cells to differentiate into neurons, and integrate into the system.”
Kirste hopes these findings will lead to treatment options for those suffering from dementia and depression as these disorders are linked with declining rates of neurogenesis in the hippocampus. Silence could essentially be used as a therapy for these cases.
Another study published in the journal Heart found that just two minutes of silence positively affected blood pressure and blood circulation in the brain. The team discovered these effects were more pronounced with silence than listening to relaxing music.
The good news is that even if you’ve suffered from the negative effects of noise pollution, the damage can be mitigated. One of the best ways to do this is through forest bathing — otherwise known as Japanese shinrin yoku.