How does Loud noise affect us?

There are many loud sounds present in our environment, some are soft and pleasing while others are loud and disturbing. Can overexposure to these loud sounds be harmful to us?

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By Adrian Sappleton

Sound-level meters measure noise levels. We record noise levels in decibels, or dB(A). The higher the noise level, the louder the noise. You can listen to sounds at 70 dB(A) or lower for as long as you want. Sounds at 85 dB(A) can lead to hearing loss if you listen to them for more than 8 hours at a time.

Loud Noise is most often used as a synonym for the term noise pollution. The first known usage of the word was in 1966

Noise Pollution

“it’s not just how loud the sound is but also how long one has been exposed to it.”

Various researchers and organizations have been researching the effects that loud noise has on people. The results of these countless studies helped to create an understanding that, it’s not just how loud the sound is but also how long one has been exposed to it. The Danish labour supervision organization in its guidelines about noise in the workplace states that prolonged exposure to noise levels over 85 dB(A) carries a risk of seriously damaging the ear. It also states that prolonged exposure to noise levels at 90 dB(A) is almost 3 times as dangerous to the ear than noise levels at 85 dB(A).

Permitted noise exposure limits
Fig.1 Table showing noise levels in dB(A) and maximum recommended exposure time.

In a guideline published by the World Health Organization regarding recommended community noise levels, it is recommended that noise levels at night should be less than 30 A-weighted decibels dB(A) in a bedroom during the night for a sleep of good quality and less than 35 dB(A) in classrooms to allow good teaching and learning conditions. Due to the correlation between night noise and adverse health effects, the WHO guidelines recommend an annual average of less than 40 dB(A) outside of a bedroom to minimise adverse health effects. (For more information check out the WHO Guideline)

The Consequences of Loud Noise on Humans

Man covering ears

Exposure to prolonged or excessive noise has been proven to cause a range of problems for human health. These problems range from stress and poor concentration to more serious afflictions such as hearing loss and cardiovascular diseases. In 2011 the World Health Organization released their report titled “Burden of disease from environmental noise”, this study was conducted over a 10-year period and collected data from other studies done on large scale epidemiological studies of environmental noise in West Europe.

The authors of the study analysed various sources of environmental noises and then studied the links to health conditions in both adults and children. Using the data collected in these studies, the WHO researchers came to the conclusion that there is overwhelming evidence that exposure to environmental noise has adverse effects on the population’s health. 

 “In Western Europe, the guidelines say, traffic noise results in an annual loss of at least one million healthy years”

Increase in noise, Increase in risk

The authors noted that while other forms of pollution are decreasing, noise pollution has been increasing. This conclusion is reinforced by the fact that there has been an increase in the number of people who have been complaining about excessive noise in the WHO region. Populations that are exposed to high noise levels can be afflicted by other symptoms such as: stress reactions, sleep-stage changes, and clinical symptoms like hypertension and cardiovascular diseases. All these impacts can contribute to premature mortality. It is important to note that these adverse health problems impact all age groups including children and adolescents. In fact, it has been reported that children who live and or study in an area afflicted with noise pollution tend to suffer from stress, impairments in memory and attention as well as difficulty reading.

 “In Western Europe, the guidelines say, traffic noise results in an annual loss of at least one million healthy years”. Traffic noise is currently ranked second among environmental threats to public health.

Table showing major sources of lloud noise
Fig. 2 Lden (noise levels day evening and night) indicator for main sources of loud noises

The danger of noise pollution is more present to us when we’re asleep. Because the human ear is so sensitive, it never rests, it is always working, picking up and transmitting sounds for our brains to interpret. This always on working process is where the danger lies, though you may be sleeping, sounds are still being picked up and processed. The most common side effects of this phenomenon are sleep disturbance and tiredness, impaired memory, judgment, and psychomotor skills. The other more serious outcomes of this can be the triggering of the body’s acute stress response, which raises blood pressure and heart rate as the body and brain go into a state of hyperarousal. According to the European Environment Agency, at least 10 000 cases of premature deaths from noise exposure occur each year, although incomplete data mean this number is significantly underestimated. 

Current Solutions

With all the devastating and long term effects of noise pollution yet to be revealed, it is important that there are some organisations and directives such as World Health Organization and the European Noise Directive (which is the main European Union (EU) legal instrument through which land-based noise emissions are monitored and actions developed).

“further efforts are needed to decrease noise pollution in Europe and the rest of the world”

These organisations have been very involved in investigating both the short- and long-term effects of prolonged noise exposure on humans and the environment. The first step of treating any problem is first acknowledging the problem and its effects and then it will be possible to develop efficient methods to counter them. Though it is important to note that, further efforts are needed to decrease noise pollution in Europe and the rest of the world. There is also a clear need to for members to improve their implementation of the Environmental Noise Directive, with respect to the completeness, comparability and timeliness of reporting.

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