A car alarm wailing across the parking lot. A fire drill down the street. Traffic you're so used to hearing that you barely notice it. Trains clattering around overhead and underfoot. Garbage trucks and delivery trucks and snowplows rumbling along. And that’s even if you don’t work in a factory, an airport, a warehouse, a hospital, a Starbucks during the morning rush, or any number of other places where the volume gets turned up to 11 all day long.
Cities are loud. We get used to it, but just because we’re used to it doesn’t mean the noise doesn’t affect us – after all, most people are also used to eating refined grain products laced with sugar and food coloring for breakfast, but that doesn’t make it healthy. Just like we evolved to live in a certain kind of food environment, we also evolved for a certain kind of noise, and it’s not the noise environment of the modern city.
But here’s the good news: noise is a lot easier to control than a lot of modern stressors, and with some tweaking you can even make it work to your advantage. The stress of noise exposure is one small opportunity to reduce your overall stress burden, and every little bit helps. So here’s a look at how the wrong kind of noise can actually be bad for your health, and how the right kind of noise can help you out.
Noise = Stress
Noise is a stressor, and just like any other stressor it ramps up the sympathetic nervous system (the “fight or flight” response), complete with higher levels of adrenaline and the “stress hormone” cortisol. That's why upbeat music wakes you up and makes you feel energetic, and also why a sudden bang can set off a full-on heart-pounding, sweaty-palmed panic response until you figure out what’s causing it. Just like bright lights, loud noise is a signal to your body that there’s something going on that it needs to be alert for.
That’s just fine when the loud noise is a one-time thing. If there really is a car crash in your immediate vicinity, you probably want to be keyed up about it and ready to run away very fast; and the stress response adrenaline dump will help make that happen. But when that stress response is always turned on because you’re chronically exposed to noise pollution, then the noise turns into a chronic stressor. This study, for example, found that higher levels of noise stress caused a more intense state of chronic physiological stress among workers in a long-term care home.
Chronically high cortisol means that you never get to relax; physically, your body is “turned on” all the time. If you’re not familiar with all the dangers of that, a partial list would include: gut dysfunction/Irritable Bowel Syndrome, weight gain/metabolic damage/insulin resistance, mood disorders, sleep disorders, immune weakness, and sugar cravings. Stress throws your normal hormone balance completely out of whack – it’s arguably even worse than a bad diet.
Chronic Noise and Sleep
Just to take one reasonably well-studied example, chronic noise stress can disrupt your sleeping patterns, even if the noise isn’t going on while you’re actually trying to rest.
Noise stress raises levels of the stress hormone cortisol, even after you’re not hearing the noise any longer. For example, this study found that workers who worked in noisy environments had higher levels of evening cortisol after their shift on workdays than they did at the same time on their days off. That’s a problem because cortisol is supposed to dip at night so you can wind down and go to bed. Higher evening cortisol means that those workers probably had more trouble getting high-quality sleep, because physiologically they were still keyed up from the noise.
It gets even worse if you actually do have to deal with the noise at night. Just to take one example, this study found that airport noise in particular was associated with poor sleep quality, and this study found the same thing for general traffic noise.
Bad sleep or disrupted is a very quick road to all kinds of chronic problems – mostly the same problems caused by chronic stress (after all, sleep deprivation is a kind of stress in its own right). Take a look:
Noise, Sleep, Stress, and Health
All this stress and sleep deprivation has a noticeable effect on overall health. This study, for example, found that noise exposure was negatively associated with overall health-related quality of life.
This study reviewed the effect of noise-related sleep deprivation on mortality, especially cardiovascular disease and respiratory infections: the sleep disturbance caused by background traffic noise is enough to notably increase risk of both.
This one cut out sleep as a middleman and cut straight to the chase: airport noise exposure was associated with increased waist circumference, representing a higher amount of visceral fat (that’s the more dangerous kind). Blood pressure is another victim: in this study, traffic noise was associated with hypertension, and here’s another study associating noise stress with higher blood pressure among construction workers exposed to noise as part of their workdays.
In other words, chronic noise stress is a stress like any other stress, and the consequences for your gut health, sleep quality, and hormonal balance are just as real. Just because we’re used to it doesn’t mean it’s healthy.
Noise and Stress Relief
Unpleasant or constantly loud noise can be stressful. But that doesn’t mean we should all walk around wearing earplugs all the time! The right kind of noise can actually be an effective stress-reducer.
Just for example, this study found that listening to nature sounds actually helped lower subjects’ cortisol levels and reduce their stress. And surprisingly enough, patients with IBS were even more sensitive to this: they found irritating noises more stressful, but they were also more receptive to the calming effect of nature noises.
Shaping your Sound Environment
There’s also another piece of good news: noise is a stressor you can control. You might not be able to quit a lousy job, or avoid a horrible commute, but you can at least do something about the typical level of noise in your day!
- Save the loud music for times you want to be awake, like early in the morning.
- Use calming noises like soft music or nature sounds to help you wind down and let go of stress - especially if you have stress-related gut problems.
- Block out any background noise as much as you can while you’re sleeping or eating, even if you think you “don’t hear it.” Invest in a good set of earplugs if you live next to an airport or along a busy street. Eat in a calm sound environment and keep the background music low.
- If you have a noisy work environment, first of all make sure that you have the proper safety gear. But even above that, you might want to consider ear plugs, or at least frequent breaks to get out of the din.
It doesn’t have to be perfect, but keeping your noise environment comfortable can be one of those little things that adds up to a big benefit in the long run – and besides, it’s just more pleasant. It’s a little piece of stress that you can control to keep your overall stress burden as low as possible.