Sound is a form of energy that can disturb living beings. In human beings, the ears are the hearing organs.
The human ear is capable of perceiving up to about 85 decibels of sound. Exposure to sound above 85 dB can begin to cause hearing damage over time, such as factory noise or loud music. Prolonged and loud sound is commonly considered noise.
Sound is a type of vibration. This vibration can travel through air, water, or solid objects. The ear can sense this vibration and energy to a certain level.
Different objects and organisms produce various types of sound, such as birds, dogs, music, TV, etc.
When sound energy and vibration exceed the human ability to hear and understand, it becomes a pollutant. When sound levels surpass the threshold of human comfort, it is termed noise pollution.
Noise cannot be heard clearly, and only mixed and disturbing sounds will be perceived by the human auditory system.
Definition and Causes of Noise Pollution
Noise is defined as
“the unwanted, unpleasant, or disagreeable sound that causes discomfort to all living beings.”
In general, the term defines an unwanted sound at the wrong time and wrong place.
According to Britannica,
“noise pollution, unwanted or excessive sound that can have deleterious effects on human health, wildlife, and environmental quality.”
Noise irritates the human ear. Besides that, the effects of noise pollution include;
- Hearing problems
- Health issues
- Sleeping disorders
- Cardiovascular issues
- Communication troubles
- Effects on wildlife
The unwanted sound can come from sources like vehicles, the automobile industry, machines, humans, animals, aircraft, etc.
It is the second-largest environmental cause of health problems after air pollution.
Reportedly, about 90% of noise-related costs come from transportation sources; passenger cars and heavy goods vehicles.
According to the United States Environmental Protection Agency,
“The traditional definition of noise is “unwanted or disturbing sound”. Sound becomes unwanted when it either interferes with normal activities such as sleeping, conversation, or disrupts or diminishes one’s quality of life.”
Similar to air and water pollution, noise pollution is a serious global issue affecting human health and contributing to the general deterioration of environmental quality.
Causes of Noises pollution:
Causes of noise pollution include;
- Industrialization
- Poor urban planning
- Social events
- Transportation
- Household chores
- Construction activities
- Electronic devices
- Aircraft and Trains
Types of Noise:
Noise is classified into these types:
- industrial or occupational noise (industrial machines, engines, etc)
- transport noise (road, rail, or air traffic)
- neighborhood noise (TV, speakers, juicer machines, etc).
Industrial noise:
Industrial machines cause high-intensity noise. Machines from various factories, mills, and industries are a major source of noise pollution in the environment. It is a nuisance to workers, the public, and animals.
Workers particularly suffer from occupational pollution produced by industries during their 8-hour shifts.
Transport Noise:
Traffic noise from roads and highways, railways, and aircraft is another major source of noise pollution.
With industrialization and modern technology, the human population relies on vehicles for their movement, further aggravating the issue of noise pollution. The noise level in highly populated residential areas in cities has surpassed normal levels, exposing humans to the consequences of noise pollution.
The elderly suffer the most. Children are losing the ability to focus on tasks. Hearing disabilities are becoming more widespread and severe.
Neighborhood noise:
Household gadgets, electronic devices, and the surrounding community contribute to neighborhood noise. TVs, MP3 players, juicers, lawnmowers, loudspeakers, etc., contribute to neighborhood noise.
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Sound and Its Properties
- Frequency: The unit of frequency is Hertz. It measures the rate at which compression waves arrive or pass a fixed point. Below 20 Hz is called infrasound while above 20000 Hz is termed as ultrasound. The audible range for humans is 20-20000 Hz.
- Pitch: It is the human perception of sound frequency.
- Intensity: It is acoustical power or the energy delivered by sound per unit area.
- Loudness: It is the human perception of sound’s intensity. Loudness is measured in decibels (dB).
It’s worth noting that individual perceptions of noise can vary. Some sounds can be a cause of disturbance for some people but music to the ears for others. For instance, a music concert or a house party may be enjoyed by many but can be a nuisance for others.
Since the Industrial Revolution, noise levels in the environment have been rapidly rising. A WHO study shows that approximately 1.6 billion people globally are exposed to unsafe noise levels, mainly from road traffic and industrial activities.
Sound intensity is measured in decibels (dB). A dB is the tenth part of the larger unit, Bel.
How loud is too loud? Guidelines on Safe Noise Levels
WHO recommends less than 30 dB(A) at night for quality sleep and under 35 dB(A) in classrooms for effective learning. The WHO advises staying below 40 dB(A) for night noise outside bedrooms to prevent health impacts.
“Noise is an underestimated threat that can cause a number of short- and long-term health problems, such as for example sleep disturbance, cardiovascular effects, poorer work and school performance, hearing impairment, etc.”
WHO
Noise pollution occurs when it an excessive amount or an unpleasant sound disrupts natural balance. Such sounds are unnatural in their volume or their production.
In today’s technologically advanced world, it has become increasingly difficult to escape noise.
| Category | Details |
|---|---|
| Definition | Noise-Induced Hearing Loss, or NIHL, happens when you listen to loud sounds. |
| Risk Factors | 1. Sound intensity (measured in decibels, or dBA) 2. Proximity to noise source 3. Duration of exposure |
| Safe Noise Levels | Sounds at or below 70 dBA are safe for long exposure. 85 dBA for 8 hours is the threshold for risk. |
| Dangerous Noise Levels | Above 85 dBA can lead to hearing loss. For every 3 dB increase, safe exposure time is halved (e.g., 85 dBA for 8 hrs, 88 dBA for 4 hrs, etc.). |
| Impulse Noise | Short bursts like gunfire or fireworks over 140 dBP can cause immediate, permanent hearing damage. |
| WHO Guidelines | Recommended exposure for adults: 80 dB for 40 hrs/week; for children: 75 dB for 40 hrs/week (e.g., for smartphones or personal audio players). |
| Signs of Excessive Noise | – Raising your voice to be heard – Difficulty understanding speech – Ringing in ears (tinnitus) – Muffled hearing |
| Health Effects | Can lead to hearing loss, tinnitus, high blood pressure, sleep problems, and stress. |
| Hearing Protection | Use earplugs or earmuffs (reduce noise by 15-30 dB). Limit exposure time Lower device volume (max half volume) Buy quieter products |
| Noise Sources | Dangerous Noise Levels – 150 dBP = Fireworks – 140 dBP = Firearms – 130 dBA = Jackhammer – 120 dBA = Jet takeoff, siren Extremely Loud Noise Levels – 112 dBA = MP3 player max volume, rock concert – 106 dBA = Gas blower – 100 dBA = Tractor, earphones Safe Noise Levels – 70 dBA = Group conversation – 60 dBA = Conversation, dishwasher – 40 dBA = Quiet room |
What are the Effects of Noise Pollution?
Noise pollution can affect both humans and animals. Health effects include the contraction of blood vessels, excessive adrenaline in the bloodstream (responsible for high blood pressure), heart attacks, mental distress, loss of focus, neurological problems, nervous breakdowns, stress and tension, loss of sleep, and more.
The immediate and acute effect of noise pollution is the impairment of hearing ability. It affects the auditory system. Prolonged exposure to high-intensity noise can lead to chronic ear damage.
The adverse health effects of noise pollution lead to unproductive work, bringing about changes in one’s overall behavior. It can cause damage to the heart, liver, kidneys, and other vital organs.
Emotional disturbance is a key issue related to noise pollution exposure. Noise pollution has been linked to hypertension, sleep disturbances, and mental health issues, especially in densely populated urban areas.
Psychological and pathological disorders can be caused by environmental noise. Meanwhile, ultrasound can affect the cardiovascular, respiratory, and digestive systems. Loud and sudden noise can adversely affect the brain and could lead to psychiatric illness.
Studies have reported that blood pressure is induced by excessive noise levels. Noise pollution also reportedly affects the human optical system, with effects including pupillary dilation, night vision impairment, and a reduction in color perception ability.
The World Health Organization (WHO) warns that 1.1 billion young people are at risk of hearing loss due to unsafe use of personal audio devices and exposure to loud sounds in places like nightclubs and sporting events. This can have serious impacts on physical and mental health, education, and employment.
According to a European Union (EU) publication:
- about 40% of the population in EU countries is exposed to road traffic noise at levels exceeding 55 db(A);
- 20% is exposed to levels exceeding 65 dB(A) during the daytime; and
- more than 30% is exposed to levels exceeding 55 dB(A) at night.
Vulnerable groups include children, the elderly, shift workers, and those in lower-income areas with poor insulation. Children’s education and health are especially at risk from chronic noise exposure, which may have lasting effects on their development.
Noise Pollution physiological effects include;
- Respiratory system problems
- Loss of physical control
- Dizziness
- Stress
- Nausea
- Vomiting
- Disorientation
Here are some common psychological effects from noise pollution;
- Hearing impairment
- Causes Accidents
- Mental disturbance
- Loss of concentration
- Reduced work efficiency
- Sleeping issues
According to WHO studies, Noise pollution is the second largest environmental cause of health issues after air pollution. While air pollution causes more premature deaths, noise pollution has a greater impact on quality of life and mental health.
Health Impacts (estimates):
- Long-term noise exposure leads to 48,000 new cases of ischaemic heart disease and 12,000 premature deaths annually.
- 22 million people experience chronic high annoyance, and 6.5 million suffer from chronic high sleep disturbance.
- 12,500 schoolchildren are affected by reading impairments due to aircraft noise.
Source: Eulalia Peris – EEA Environmental noise expert citing EEA report ‘Environmental noise in Europe — 2020’
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Noise Pollution Effect on Wildlife
Wildlife is more sound-dependent than humans. The survival of many animals depends on their sense of hearing. Therefore, they face more problems with noise pollution.
Animals are more easily disoriented with loud sound affecting their general behavior. In nature, they may suffer from hearing loss which could lead to them being easy prey to predators. This ultimately affects their population number.
Pets in households can start to react more aggressively when constant noise problem.
Many species depend on mating calls to reproduce.
Many species require sound waves to echo-locate and find their way.
Disturbing these sound singles and wave projections disturbs whole animal populations.
Animals can themselves become louder to cope with the increased sound levels in nature, further increasing the level of noise.
What are Noise Pollution Control Measures?
Noise pollution can be controlled by measures that include sound source control, transmission path intervention, and protective measures.
These are some of the most effective ways to reduce noise pollution.
Source Control:
Reduction and modification of noise at the source can make it bearable. For instance, acoustic treatment of machine surfaces, design changes, and limiting operational timing can have positive effects on the source of noise.
Transmission Path Intervention:
This control measure includes strategies to contain the source inside a sound-insulating enclosure, the construction of a noise barrier, or the provision of sound-absorbing materials along the path of the sound.
Planting trees around houses and buildings can effectively act as a noise barrier.
Highly absorptive materials for walls, ceilings, and floors can help reduce noise levels in indoor environments.
Increasing the path length:
Increasing the overall distance from the source of the noise to the recipient can largely reduce the impact of noise. This can be taken in mind when building airports and railway tracks away from populated areas.
Receptor Control:
Changing work schedules and providing personal protective equipment can help control the effects of noise intensity. Dissipation and sound deflection methods can also be very helpful.
Oiling:
Proper and timely oiling of machinery can greatly reduce noise levels.
Preventive and Protective Measures:
To protect against noise pollution, people should wear earplugs in loud environments, have regular hearing tests, and be aware of harmful noise levels. Educating others on the risks is also crucial.
Here are a few preventive measures that need to be taken to reduce the impact of noise pollution on the living population:
- Noise limits on vehicular traffic
- Mass public transportation
- Low-noise road surfaces, quiet public transport, and infrastructure for electric vehicles.
- Banning honking in populated areas
- Silence zones near educational institutions and hospitals
- Reducing traffic density in residential areas
- Building airports and railway stations away from residential areas
- Designing buildings and homes to make them noise-proof
- Proper care and maintenance of machinery in industries and factories
- Public awareness campaigns
- Planting trees and creating green spaces
- Quiet areas like parks and nature reserves to combat urban noise
- Shielding noise sources with highly absorptive materials
- Shifting noise pollution sources away from living organisms
- Banning the use of loudspeakers in public places
- Use of earplugs in high-noise areas
- Strengthening laws and regulations, governmental efforts, and environmental networks
