Back in 1896, a journal article titled “The Plague of City Noises” set off the 19th century’s version of a Twitter meltdown. The article highlighted “the injurious and exhausting effects of city noises on the auditory apparatus, and on the whole nervous system,” and generated “hundreds” of editorial comments and “scores” of private letters across the United States and Europe.

“Almost without exception… the medical press agreed with the contention that the noises of our modern cities are not only a source of great discomfort, but are largely life-shortening and health-wrecking in their effects,” the author of an article on the phenomenon wrote the following year.

Fast-forward to 2011, and a report from the World Health Organization (WHO) came to similar conclusions. The authors concluded that in western Europe alone, roughly 1 million healthy life years are lost each year as a result of traffic-related noise. Noise is inherently arousing, and the long-term effects of “chronic noise stress” on the human hormone and nervous systems are a growing concern, the report states.

Just as the human digestive system can be overwhelmed by the sugar and calories packed into contemporary diets, noise pollution experts say the human brain and nervous system can be overwhelmed by the amount of ambient noise packed into contemporary life.

“You can close your eyes, but you cannot close your ears.”

“The auditory system is continuously analyzing acoustic information, including unwanted and disturbing sound, which is filtered and interpreted by different brain structures,” says Wolfgang Babisch, a former research scientist with Germany’s Federal Environment Agency who has studied the effects of noise on human health and authored a chapter of the WHO report.

Our brain’s always-on auditory system was designed to operate in natural environments — not in cacophonous cities and suburbs. There’s increasing evidence that ambient-noise exposure can contribute to metabolic disorders ike Type 2 diabetes, high blood pressure, heart disease, and stroke, Babisch says. There’s also evidence linking noise-related annoyance to poorer mental health.

How can noise do damage? Loud or unpredictable sounds can activate the body’s sympathetic nervous system (SNS) and trigger an increase in stress-related hormones like epinephrine and cortisol, Babisch says. Over time, this SNS activation and its accompanying stress-hormone spikes can lead to increases in blood sugar, blood pressure, and blood viscosity, which in turn can contribute to health problems.

A study published this year by Thomas Münzel, a professor of medicine at the University Medical Center of Johannes Gutenberg University Mainz in Germany, found that exposure to loud environmental noise can also increase a person’s risk for irregular heartbeat. In another 2018 report, Münzel detailed the ties between loud noise and heart failure, heart attack, and stroke — as well as noise’s negative impact on a person’s sleep and cognitive performance. He says anything as loud as about 70 decibels — roughly the noise generated by a passing car — could be considered “unhealthy noise,” because it can disturb sleep, and poor sleep is a risk factor for health issues ranging from heart disease to obesity to diabetes.

“You can close your eyes, but you cannot close your ears,” Münzel says. During sleep, sudden or loud noises can lead to significant increases in a person’s blood pressure, even if that person doesn’t wake up, he says.

The effect different noises have on your health depends in large part on context and your sensitivity to the sound. “People can acclimate to noise,” Babisch says. A longtime city dweller may not notice, or mind, the ambient clatter outside her urban office window, while these same sounds may rile a person accustomed to quieter, rural environments.

But regardless of its decibel level, any noise that disrupts your concentration or annoys you — whether it’s your co-worker’s laugh, a neighbor’s barking dog, or your kids’ shouting — is enough to activate your nervous system and contribute to negative effects, including raising your risk for mental illness. “The higher the degree of annoyance, the higher the likelihood of depression and anxiety disorders,” Münzel adds. Along with disrupting sleep, annoying noises promote stress, which can contribute to these conditions, his research suggests.

Even music can be arousing and stress-inducing, says Joanne Loewy, an assistant professor and director of the Louis Armstrong Center for Music and Medicine at Mount Sinai Beth Israel. Up-tempo music with a lot of notes can accelerate a listener’s heart rate and breathing. While this can be helpful during exercise or those times when you want to pump yourself up, it’s not so great when you’re driving in heavy traffic or trying to unwind, she says.

Masking or blocking out loud or annoying sounds whenever possible can help combat all of their negative health effects. Depending on the situation, earplugs or noise-canceling headphones can help with this, Babisch says. So can soft music, fans, or white-noise machines — all of which can cover up distracting noises. There’s also evidence that listening to natural ambient sounds — rain, the rustling of leaves, the tumble of ocean waves — can help calm your nervous system and combat stress.

Total silence, on the other hand, should not be your goal. Just as the human brain and auditory system weren’t designed to live in noisy environments, they also don’t seem to respond well to an absence of sound. “Complete silence can also cause stress,” Münzel says.

The bottom line is that life has gotten loud. It may be time to turn down the volume.