Here's an excuse to escape urban life and go camping: Environmental noise - as in that airport you live next to - is more of a nuisance than you probably realize, sapping your energy and risking your health even while you're not conscious of it, according to a recent review by the University of Pennsylvania School of Medicine.
Researchers believe that noise at night generally presents a greater risk than exposure during the day.
Why? It's obvious: We can't avoid noise while we sleep as easily as when we're awake, says review author Mathias Basner, assistant professor of sleep and chronobiology in psychiatry at the University of Pennsylvania School of Medicine.
Superficial sleep (as opposed to deep sleep and rapid eye movement sleep) is prone to disturbances and comes toward the end of the sleep cycle, so the sound of your neighbour using his leaf blower in the early hours is likely to puncture your serenity with annoyance, physical restlessness (body movement), or awakenings - during the stages when it's hardest to doze off again. When the time comes to face the day, you probably won't perform at your athletic best: Although not incredibly surprising, a recent study has found that sleep deprivation increases our perceived exertion and makes us inclined to quit sooner.
Night-time noise also has long-term health ramifications. "Your auditory system is pretty much awake all the time," says Basner, and perception doesn't simply turn off while you're unconscious.
Any auditory input is relayed to the cardiovascular system, even if it doesn't wake you. Your blood pressure will spike, preparing you to encounter the source of the noise, without you realizing it - whereas a healthy sleeping blood pressure is low and experiences dips.
According to the review, any noise exposure over 55 decibels is liable to induce cardiovascular disease. (What you hear while conversing with someone typically ranges between 60 decibels and 65 decibels.) Optimum night-time noise is 40 decibels or lower. Cars shooting past or planes growling overhead - or your leaf-blowing neighbour - are not annoyances to simply shrug off. "Close your windows at night," Basner recommends, "or move to a window that doesn't face traffic."
And if you haven't noticed your sleep disturbed, or your ability to perform checked, bear in mind that Basner says we "habituate very quickly" to feelings of sleepiness. We learn to accept our disruptions: "If you move somewhere noisier than before, you adapt to that level of noise." You may not wake up, but the arousals - and their negative health implications - will still occur.
To ensure peak performance and to prevent cardiovascular problems while living in a noisy environment, consider earplugs (if you can tolerate them) or noise-cancelling headphones. White noise - such as a fan - is less disturbing than sudden, intermittent noises (a plane taking off, bursts of traffic), but whether or not you can use white noise for sound masking is still under investigation.
If nothing else, you might try more sojourns in the placid, pine-muffled wilderness to keep yourself energized and healthy - insofar as you don't have to deal with morning snowmobilers.