Engines revving, dogs barking, bass blasting – no matter how hard we seek peace and quiet, it’s hard to escape the constant bombardment of noise. At a conscious level, we are often oblivious to the effects of this noise, but our minds and bodies are certainly feeling it.
In fact, excessive noise can adversely affect our sleep, stress levels, and ability to concentrate. Of course, it’s impossible to exclude every kind of noise from our environment, and even when we are fast asleep our hearing mechanism is always on.1
Noise pollution, like any other form of pollution, is a threat to our health and well-being. The cumulative effects of noise pollution can be felt in every area of our lives – from our homes to our social, working, and learning environments – and can cause economic losses as well as more intangible health risks.2
How Loud Is Too Loud?
Community noise is noise emitted by any kind of source, aside from industrial noise. This is also referred to as environmental, residential, or domestic noise. The World Health Organization (WHO) has specific recommendations for acceptable community noise:
- Less than 30 A-weighted decibels (dBA) for good sleep
- Less than 35 dBA in classrooms to enable conducive teaching and learning conditions
- Less than 40 dBA of night noise outside bedrooms to avert any harmful effects from night noise
The average person’s normal hearing sensitivity, or ability to detect sounds, is at about 20 Hz to 20,000 Hz, though individual hearing sensitivity varies due to different environmental influences. Interestingly, women generally have better hearing than men in industrialized countries.3
Can You Feel The Noise?
Noise-Induced Hearing Loss
Long-term exposure to high levels of noise, such as that in industrial settings, or a one-time exposure to an intense sound can cause hearing loss. Regular exposure to loud noise, even from loudspeakers and headphones during recreational activities, can also impair hearing.
It is generally accepted that noise levels below 70 dBA do not cause hearing impairment even if the exposure is for a long duration. However, more than 8 hours of exposure to noise levels above 85 dBA is dangerous. To understand what that means, 85 dBA is equivalent to the noise on a busy road with heavy truck traffic. Exposure to such loud noises results in the loss of auditory sensory cells in the cochlea of the ear. Since these cells can’t regenerate, there is no going back.
A Major Occupational Hazard
In the United States, about 22 million workers are exposed to hazardous noise levels at work. Noise-induced hearing loss is an anticipated harm in industrial settings. For the protection of workers in these environments, health and safety legislation lays down specific maximum exposure levels, and requirements for noise assessments, protective equipment, audiometric testing, and regular monitoring.
Musicians, bar workers, and those working with the armed forces, among others, are also exposed to excessive noise that could lead to hearing loss.4
And A Detriment To Your Everyday Life
Hearing loss can have severe social effects by hampering everyday interactions with others. Even partial hearing loss reduces our sensitivity to sounds that our ears unconsciously pick up to regulate the body’s rhythm. Hearing loss can lead to an increase in accidents and falls, and a decrease in attention to certain tasks. It can also cause distortion in hearing, tinnitus, and errors in perceiving the loudness of sounds.5
Reaching Max Volume: WHO Recommendations
When you are exposed to sound higher than 165 dBA, there is no question of getting used to or getting over the noise – deafness is the only sure result. Remember that firecrackers and even some toys can generate enough noise to cause hearing loss.
According to WHO recommendations, one should not be exposed to noise levels greater than 100 dBA more than 4 times a year, and not more than 4 hours at a time. Consider these:
- A snowmobile or a jackhammer produces noise levels of 100 dBA or more.
- Exposure to sounds such as that of gunfire or other sources that produce intense noise over a short duration should not cross 140 dBA in adults and 120 dBA in children.
- A noise level of 140 dBA is also the threshold for pain.
- Anything higher than 165 dBA causes permanent cochlear damage.6
Noise Can Damage Far More Than Your Ears
While it’s a well-known fact that continuous exposure to loud noise, especially in industrial settings, leads to hearing loss over time, there are other sources of environmental noise that still have adverse health effects – some that are not even auditory.
It’s Wrecking Your Sleep
A noisy environment disturbs sleep in various ways. Studies show that indoor noises above 50 dBA affect sleep more than outdoor noises of the same magnitude. Noise exposure during sleep has been found to trigger an increase in heart rate, pulse rate, blood pressure, and body movements. Disturbed sleep could also have after-effects on mood and performance during the following day.
Studies show that reduction of indoor noise levels helps improve sleep quality. While some amount of adaptation to regularly occurring noise disturbances does occur over time, complete adaptation – especially when it comes to your heart rate – does not happen.7
It’s Impacting Your Mental Performance
Studies have shown that one’s ability to perform complex mental tasks involving memory, recall, and choice of strategies for carrying out tasks becomes impaired after noise exposure. Noise has also been found to increase aggression and decrease helping behavior.8
It’s Raising Your Blood Pressure
Physiological changes such as increase in blood pressure, heart rate, ischemic heart disease, and vascular constrictions can occur after prolonged exposure to noise. Studies indicate that those who are continuously exposed to noise levels of a minimum of 85 dBA have higher blood pressure than those not exposed to such noise. Of course, it must be mentioned that, along with noise, there is often exposure to other physical and psychosocial factors that contribute to this rise in blood pressure. Industrial studies also show that high noise levels are more likely to raise the blood pressure of individuals doing complex jobs than those doing simpler jobs. Continuous exposure to such noise levels increases mortality risk as well as the chances of accidents during normal daily activities such as driving.9
Studies around certain European airports have connected airplane noise exposure to both hypertension and heart trouble. Although study results have not always been consistent, there is a high chance that airplane noise affects total cholesterol, systolic pressure, viscosity of blood, platelet count, and glucose levels.
Also, a sudden, unexpected loud noise could stimulate catecholamine (hormonal) secretions and cause cardiac dysrhythmias or abnormal heartbeat. In fact, one study observed a decrease in catecholamine secretion when employees working in high-noise areas wore hearing protection against noise.10
It’s Increasing Your Stress Levels
Noise exposure could lead to serious psychological effects, too, though a direct connection has not been confirmed. Perceived annoyance levels are often dictated by how a person interacts with their environment. Those who have better abilities to deal with stress are affected less.
In high-noise areas such as factories and schools, community surveys report complaints of headaches and nausea and feelings of being edgy, tense, argumentative, and restless at night. That said, there may be other factors beyond noise that are contributing to such symptoms.11
Your Children’s Ears Are Taking A Beating
Children are very vulnerable to non-auditory health effects of noise. As their cognitive capacity to understand and anticipate causes of stress is not developed, they do not have the coping strategies of adults. Further, since children are still developing in every aspect, over-exposure to loud noise could have irreversible negative consequences on them.
Studies have proven that noise-exposed children have difficulty concentrating when compared to children who come from quieter surroundings. The former also exhibit poorer ability to differentiate between different sounds – of speech or otherwise. They have poorer reading ability and perform poorer in tasks that need high processing and memory recall. Fortunately, tests indicate that a change in noise levels can reverse these damages.
Other studies with children show that prolonged exposure to high noise levels also affects their systolic blood pressure, endocrine levels, and annoyance levels. Even young children showed annoyance at high noise levels. 12
The Elderly Are Vulnerable
The elderly are another vulnerable group affected by noise pollution. Even hospital noise levels are sometimes too high for some elderly patients who do not have the mental or psychological reserves to tolerate or adapt to high noise levels. It can even affect their recovery speed.13 Other studies conclude that continuous exposure to traffic noise during the day or night is associated with growing incidents of diabetes, stroke, hypertension, and coronary heart disease among the elderly.14
Animals Need Relief From The Noise, Too!
Animals, including aquatic animals and birds, are conditioned by nature to thrive despite the continuous noise from various natural sources such as wind, water, and other animals. However, anthropogenic noise, that is, noise of human origin, is fast becoming an influential pollutant that can impact animal behavior and reproduction.
As in humans, continuous exposure to loud noise or even a single incident of extremely loud noise can cause hearing damage in animals too. For example, loud noise can affect the swim bladder in fish. This organ is not only involved in hearing but also in buoyancy control.
Animal studies also indicate that environmental noise can cause DNA damage and changes in gene expression and cellular processes related to physiological, immunological, and neural processes.15
Noise: A Problem Since Forever
Has noise always troubled us? Apparently so! Ancient Rome had a ban on chariots moving on streets in the night because the noise was annoying and disturbed sleep. Centuries later there was a similar ban in medieval Europe – they even covered their streets with straw to keep down noise from carriages. When the US Constitution was being drawn up, streets in Philadelphia were covered with earth to reduce noise-induced interruptions!16
|↑1, ↑2, ↑5, ↑16||Berglund, Birgitta, and Thomas Lindvall, eds. Community noise. Stockholm: Center for Sensory Research, Stockholm University and Karolinska Institute, 1995.|
|↑3||Data and statistics. WHO, Europe.|
|↑4||Basner, Mathias, Wolfgang Babisch, Adrian Davis, Mark Brink, Charlotte Clark, Sabine Janssen, and Stephen Stansfeld. “Auditory and non-auditory effects of noise on health.” The Lancet 383, no. 9925 (2014): 1325-1332.|
|↑6||Goines, Lisa, and Louis Hagler. “Noise pollution: a modern plague.” SOUTHERN MEDICAL JOURNAL-BIRMINGHAM ALABAMA- 100, no. 3 (2007): 287.|
|↑7, ↑8, ↑9, ↑10, ↑11, ↑12||Stansfeld, Stephen A., and Mark P. Matheson. “Noise pollution: non-auditory effects on health.” British medical bulletin 68, no. 1 (2003): 243-257.|
|↑13||Bharathan, T., D. Glodan, A. Ramesh, B. Vardhini, E. Baccash, P. Kiselev, and G. Goldenberg. “What do patterns of noise in a teaching hospital and nursing home suggest?.” Noise and Health 9, no. 35 (2007): 31.|
|↑14||Halperin, Demian. “Environmental noise and sleep disturbances: A threat to health?.” Sleep Science 7, no. 4 (2014): 209-212.|
|↑15||Kight, Caitlin R., and John P. Swaddle. “How and why environmental noise impacts animals: an integrative, mechanistic review.” Ecology letters 14, no. 10 (2011): 1052-1061.|