Screaming sirens. Rumbling trucks. Thundering turbojets. Modern life is loud, yet too much sound is bad not only for hearing but for overall health. Peace and quiet, it turns out, are as good for you as a healthy diet and exercise.
Noise (noise is unwanted sound), whether a loud burst or a steady irritation, is linked to everything from insomnia to irreversible hearing loss, higher stress levels and high blood pressure. These medical after-effects may creep up silently, but their consequences can be just as alarming as the wailing of an ambulance. Throbbing low-frequency noise, like that coming from air conditioners, factories or diesel trucks, is thought to be especially aggravating.
Why is noise such a headache? Thank your nervous system, whose senses help you survive. Healthy ears pick up everything from crackling leaves, which may signal a stealthy predator, to the wail of a newborn, the rumble of thunder or the roar of a hungry lion. And they never stop. Even during sleep, sudden, loud or menacing sounds will trip an inner alarm that tells the brain to hustle the body into fight or flight.
Next, streaming stress hormones raise blood pressure and make muscles contract. In the short term, we’re more alert, maybe shocked from slumber. That leaves us cranky and forgetful. Over time, steady over-stimulation can cause chronic high blood pressure, muscle tension, upset stomach and insomnia – changes linked to serious health problems, from depression to a higher risk of stroke and heart disease.
Finally, people don’t get used to noise. The nervous system takes each new sound fresh. What’s more, it can’t tell a noisy lawnmower from an angry volcano. Thus, short of moving to the far side of the moon, the healthiest solution is to avoid or block as much noise as possible.