The Effects of Noise

Noise has become an overwhelming problem in our society, with noise pollution a designation for one of the pervasive harmful substances in our environment. Several factors contribute to this condition of excessive noise in both internal and external environments. Increases in population density in both urban and suburban areas mean more cars, more planes, more traffic, more road construction, more lawn mowers and leaf blowers, and so forth. Airports are a long-standing source of unwanted environmental noise. Yet, air travel is increasing as our economy becomes truly global. Freeways continue to proliferate as urban sprawl continues to occur, which extends the reach of noise pollution to areas that were once more rural than their suburban neighbors. And, ongoing construction to update our nation’s aging infrastructure adds to the seemingly constant din. According to Dominique Browning, editor-in-chief of House & Garden magazine, there is a growing perception of luxury in terms of lifestyle intangibles, with “quiet” considered to be one of the new luxuries.

Data from the U.S. Census Bureau shows a significant increase in the number of houses being built on smaller lots from 1999 – 2006, and that the square-footage of the homes is increasing.⁶ As homes continue to be built in closer proximity and people are living closer together, all of the sounds of running a household, including the use of outdoor power tools and equipment, are now providing increased levels of noise in the neighborhood, which makes the home not the quiet refuge form the hectic pace of the world it once was.

People who want to get away from the constant noise of contemporary life are looking for acoustical solutions in their homes. In addition, more hotels, which are being built near freeways and airports for travelers’ convenience, are using acoustical glazing for noise abatement so their guest(s) can get a good night’s sleep. Likewise, schools and hospitals are employing acoustical solutions to improve interior noise quality. As a result, there is an increasing demand for an acoustical solution in the architectural market. One of the ways to combat uncontrollable environmental noise is to actually incorporate noise-abatement properties into our architectural structures and internal environments.

As with any form of pollution, noise pollution brings its own set of adverse effects to the people who are exposed to it. It is an unwanted factor that has been proven to have a negative impact on people in terms of auditory effects including hearing impairment and permanent hearing loss, and non-auditory effects including anxious mood and irritability, depression, inability to concentrate, inability to focus on tasks, the decreased ability to read and comprehend, the inability to learn self-motivation, sleep disturbance, and the time-to-recovery for patients in hospital. ^2,4,5 Studies have shown both the physical and psychological effects of uncontrollable noise that go beyond hearing impairment and hearing loss, as well as the negative effect high levels of noise have on children’s ability to learn.

The trend of increased noise to the level of noise pollution, and its deleterious effects, has been studied in several environments including schools and hospitals. Several studies conducted around the world show that children exposed to constant and excessive noise, including air traffic noise and train noise, exhibit reduced levels of concentration, reduced reading levels, a reduced ability to understand math and overall lower levels of concentration.^4,5 Perhaps one of the most startling findings is that constant and excessive noise can lead to learned helplessness in children, which exhibits as giving up on a task at the first signs of difficulty, no matter how minor.⁴ Additionally, in the workplace, noise has been linked to increased fatigue and reduced productivity.¹

In the presence of excess noise, the body reacts as if it were being threatened and produces excess levels of adrenaline and cortisol, the body’s stress hormones. This is part of the body’s instinctive self-preservation “fight or flight” response that puts the body in a state of high alert. In addition to the rush of stress hormones, the body’s blood pressure and heart rate elevate in preparation for immediate action, blood thickens with oxygen-carrying red blood cells, and the immune system gets suppressed as the body shifts from fulfilling short-term needs instead of longer-term health.⁷ While this somatic response can be life-saving in the face of an attack, it can damage the body when it is activated chronically by constant noise. The effect can eat away at the body and lead to other serious medical conditions, including heart disease and, in some cases, heart attack.^{5, 7} Based on these findings, a realistic concern is that children who live in environments with chronic and persistent excess noise will be more vulnerable to cardiovascular disease because of the wear-and-tear it imposed on the body by keeping it in a relatively constant state of high alert.⁴

Several studies of children in home and learning environments have tested the effects of excessive and/or uncontrollable noise and the ability to learn. One study of children attending school near a noisy train track showed that, by the time the students were in sixth grade, those whose classrooms faced the train were a year behind those whose classrooms were on the quiet side of the building. After noise reduction materials were installed in the classrooms and around the tracks, reading scores in the two groups equalized, which showed that the uncontrollable train noise was the dominant factor in the learning discrepancy between the groups of students.⁷

In the hospital setting, a retrospective study was conducted to determine the effects of uncontrollable noise on the rate of patient healing and resulting length-of-stay in the hospital. The study was conducted during a period of construction, with patients’ rooms just above the construction activity. The source of noise was pile drivers, jackhammers, and dump trucks operating just outside of the patients’ rooms. Patients who were hospitalized for similar surgeries determined by type and severity of case showed a statistically significant result for exposure to excessive noise impeding the healing process. Those who were exposed to uncontrollable noise had a significantly increased length-of-stay in the hospital and a slower rate of healing and recovery time from surgery.²

According to the Environmental Protection Agency (EPA), the idea that people get used to environmental noise is a myth. Even though people think they have adjusted to noise, the physiological changes persist in the presence of excessive noise. For example, studies have shown that chronic night noise, which can create a state of fatigue, irritability, or poor concentration, also activates the stress response during sleep. Therefore, no matter how much a person adjusts to the auditory effects of noise while sleeping, the body does not adjust and the deleterious physiological effects of the constant state of the fight-or-flight response are perpetuated.⁷