Our lives are full of sounds. Some are soothing and calming, some exciting, and others distressing. Some people take steps to manage noise in their environment; this area’s relative quiet is a factor in many people’s choice to live here. Others do not realize the impact sounds or noises have on their lives. However, research is showing that sounds and noise levels, though invisible, have powerful effects on our bodies. In La Grande, an effort is underway to create a “Quiet Zone,” free of train horns; currently, railroad engineers are required to blast horns four times at each of five intersections inside our city limits. Given the growing interest in the health benefits of quieter environments, I became curious as to the effects noise has on health. Here is some of what I found.
To survive, our brains must learn which sounds are safe and which require attention and reaction. Loud noises such as barking dogs, traffic, yelling, and train horns convey “danger” to our brains, whether or not we consciously notice the sounds themselves. “The information conveyed by the noise is very often more relevant than the sound level,” according to researchers (Ising and Kruppa 2004). These sounds immediately go, unfiltered, straight to the amygdala, which is the primitive, emotional part of our brain. Loud noises especially, may be interpreted as a threat (trains’ air horns can blast up to 140 decibels or more, while a loud rock concert is around 125 decibels), and trigger the “Fight or Flight Response.” Sounds like train horns are clearly designed to warn of great danger, and our bodies react accordingly. This response is designed to improve the body’s chances of surviving a threat, and is an automatic built-in survival mechanism. Noises can trigger this reaction even as we are sleeping.
The “Fight or Flight Response” to danger primes our mind and body to survive an imminent threat. Certain powerful hormones and neurotransmitters change how our bodies work, in order to prepare for battle. Researchers around the world know that adrenalin, cortisol and noradrenaline are released in response to noise (Stansfeld, Matheson 2003; Babisch 2003). These changes may save our life, if we need them, or slowly kill us if we don’t. Blood vessels constrict, blood thickens, and clotting increases when these chemicals are released in the body, which can lead to risk of strokes and heart attack over time. Blood sugar and insulin resistance go up, increasing risk of diabetes, obesity, dementia, and hypertension, to name a few concerns. The world’s increasing noise levels often keep our bodies on constant alert, which can contribute to chronic problems such as ulcers, high blood pressure, high cholesterol, muscle tension, irritability, depression, and heart disease. As cholesterol and triglyceride levels go up because of stress, brain function goes down.
Children, due to having fewer coping skills, are especially vulnerable to impacts of noise levels. Children living in noisy areas have been shown to have higher blood pressure, more stress hormones, poorer long term memory, concentration, and comprehension, and more distractability than children living in quieter areas. Children exposed to ongoing high noise levels have also been shown to be less persistent with challenging tasks, and less motivated (Evans et al, 2000). Chronic exposure to uncontrollable, annoying noises can create a sense of helplessness, over-stimulation and anxiety. All these problems have been shown to occur at noise levels far below those causing hearing problems, and even when children were tested in a quiet place. It seems that human bodies can get stuck in survival mode. Perhaps most sadly, children who lived in noisier areas (4th graders in the studies) rated themselves less happy and more stressed than kids in quiet areas (Evans et al, 1998). Noise levels appear to affect our physical, mental and emotional health.
Noise is one of many types of stress that creates imbalances that our bodies constantly work to re-balance. A body with an excessive stress load will gradually develop symptoms and even disease. Poor sleep, irritability and tension can progress to ulcers, depression and heart disease, given enough time. Stress accumulates synergistically, and can “drag us down” over weeks, months, and years. Our health depends, in large part, upon regulating the stress in our lives that we have the ability to address.
The good news is that research also shows us the physical and mental effects of ongoing daily noise can be reversed! Take steps to make your life a little quieter. Consider how living in a “Quiet Zone,” free of train horns and/or other avoidable noises may be a boon to your mental and physical health. Rock music and even train horns can have some appeal, but rarely on a daily basis, and never at 2 am!