The Weird Thing About Noise
Posted by Liz Ernst on Thu, Sep 29, 2011 @ 02:32 PM
Noise is weird. And just as science seems to catch up with new information regarding the effects of noise on humans, some new weird factor is called into play.
Most people today understand that noise can affect humans negatively, but not everyone realizes that harmful noise is not limited to those sounds that make everyone’s pulse race and ears hurt, like police and ambulance sirens racing through the streets, loud amps and speakers at heavy metal concerts, and the ear-piercing shriek of a NASCAR event. These sounds glean the same reactions from most caught in their path, and it’s rarely a good one.
But less in-your-face sounds can be just as troubling to our hearing and health as the obvious noise offenders listed above. A growing body of scientific evidence confirms that the chronic din of ambient construction noise, road repair projects, airline traffic and even neighborhood lawn equipment is chiseling away at our sensitivity to sounds every day, and the results are not good, even if we stopped noticing them.
Noise, defined as unwanted sound, is largely a matter of individual perception. For instance, the sound of car-rocking rap tunes blasting from a passing auto are going to get a different response from the vehicle’s passengers than the residents of the quiet residential street through which it’s passing at 11:00 at night. In fact, individual perception has made it difficult to provide scientific proof of the health effects of noise, since the reaction to many sounds is going to depend on sensitivity and personal perception.
Still, study after study has found that noise in communities is interrupting our sleep, interfering with our children's learning, suppressing our immune systems and even increasing our chances of having a heart attack.
And experts on the effects of noise on our health are quick to remind us that we should not have to tolerate living with noise.
Everyday noise is under the radar, yet it affects everyone's life. No one would agree to live with “just a little” sewage in their water, so why should anyone tolerate noise pollution coming into their ears?
For instance, when your neighbor uses a leaf blower in his yard, he may be generating a sound that is only a little less intense than the 85 decibels that the National Institute of Occupational Safety and Health (NIOSH) says is physically damaging over a period of hours, but still more than loud enough to make it almost impossible for anyone within earshot to concentrate.
Modern transportation -- cars, motorcycles, trains, trucks and air traffic -- accounts for most of the background noise that disturbs and even sickens people.
More than 40 percent of Americans whose homes have any traffic noise at all classify that noise as "bothersome," according to the 2005 American Housing Survey, conducted by the U.S. Census Bureau. One-third of those say the noise is so bothersome they want to move. All told, more than 100 million Americans are regularly exposed to noise levels in excess of the 55 decibels that federal agencies have deemed reasonable in background intensity.
One Dutch analysis combined the results from 43 studies that tracked chest pains, heart attacks and related problems with community noise levels. Using a statistical technique called meta-analysis, it concluded that there is "a slight increase in cardiovascular disease risk in populations exposed to air traffic and/or road traffic noise."
Even if chronic exposure to noise is unlikely to kill you, it can simmer under the surface and take a toll on your well-being.
Studies have shown that chronic night noise not only leaves you fatigued, irritable, and struggling to concentrate the next day, it also activates the stress response as you sleep. And while the number of awakenings per night may decrease as you adjust to the noise, increased heart rate, blood pressure and breathing changes persist.
In fact, the Environmental Protection Agency (EPA) has claimed that the idea that people get used to noise is a myth. Even when we think we have become accustomed to noise, biological changes still take place inside us.
High levels of mechanical noise, such as that from a hospital's own air-conditioning equipment, can delay recovery in patients -- a reflection of the immune suppression that comes with an activated stress response.
Another insidious effect of noise is its cultivation of what scientists call "learned helplessness." Children given puzzles in moderately noisy classrooms are not only more likely to fail to solve them but are also more likely to surrender early, according to a Cornell University study. The implications of learned helplessness on a child's success in life can be quite powerful.
Perhaps most disturbing in these times of political and economic polarization is that noise undermines generosity.
In one study, people were less likely to help someone pick up a bundle of dropped books when the noise of a lawn mower was present. Another showed that in a noisy environment, people playing a game were more likely to see their fellow players as disagreeable or threatening. Yet another found a decrease in helpful behavior when loud "annoying music" was played.
Interestingly, helpful behavior increased when similarly loud "uplifting music" was played.
Which brings us back to the weird thing about noise: its mysterious psychological component.