Noise pollution: what it is, how it affects us and how it can be measured

One of the greatest environmental problems of our time is noiseImagine waking up every morning at 5:00 a.m. to the relentless roar of a motorway just metres from your window. Experiencing such high-intensity noise is n...
Read more: excessive sound or noise pollution. Although it doesn’t accumulate or transmit, noise is sound pollution that has become a serious problem for our health if we are subjected to prolonged exposure. Often underestimated, noise pollution affects both quality of life and mental health. The World Health Organization (WHO) maintains that it is an environmental pollution problem so serious for public health that it places it after atmospheric pollution.

What is noise pollution?

We are aware of hearing noise when an unwanted or unpleasant environmental sound interferes with our daily activities. A combination of sound vibrations emitted at different frequencies and intensities that becomes intolerable. It is a physical conditioning that, by becoming omnipresent, alters our well-being and that of the environment. Although noise is a type of pollution that goes unnoticed because it is invisible, in the long term, sound pollution can generate health effects as harmful as those caused by air and water pollution.

Noise pollution is defined as the presence in the environment of noises or vibrations whatever the acoustic emitter that originates them, that involve annoyance, risk or damage to people, due to the development of their activities or property of any nature, causing significant effects on the environment. Acoustics and Noise Control, R.J. Peters, 2015.

Main sources of environmental noise

Noise is not just a passing annoyance, but an environmental pollutant with serious consequences for both human health and ecosystems. Mitigating it requires identifying the main sources of environmental noise.

Urban and road traffic

It is one of the main sources of noise pollution, especially in urban environments but also on highways. Its origin is based on multiple factors, such as the volume of vehicles traveling through the same place at the same time, the characteristics of the road that cause noise due to asphalt and tire friction, and the speed at which vehicles move. In addition to this, there are air turbulences generated by vehicles, especially large and heavy ones, as well as driver behavior in crucial moments such as traffic jams and repeated braking.

«Environmental noise, and particularly road traffic noise, is a serious environmental problem in Europe. At least 20% of the EU population lives in areas where traffic noise levels are harmful to health.» Environmental noise in Europe – 2020. EEA Report 22/2019

Rail and air transport

The noise pollution caused by transport in general is among the most intrusive, particularly in the aviation sector. This industry uses high energy levels, causing noise generated by turbofan engines and aerodynamic flow around the aircraft to propagate over long distances.

In the case of rail traffic, linear corridors emit low-frequency noise derived from sound pollution generated by traction engines, wheel-rail interaction, and resulting vibrations. These factors are compounded by aerodynamic noise, a type of environmental pollution particularly disruptive in urban areas near railway lines.

Industrial and port activities

The noisy work environment of industrial zones and port facilities is a significant source of noise pollution and one of the most harmful to human health. Industrial and port noise stems from sound pollution caused by simultaneously conducting multiple production activities. Though invisible, its impact is substantial—reducing quality of life in nearby communities, disrupting terrestrial and aquatic ecosystems’ biodiversity, and endangering the health of workers continuously exposed to such noisy environments.

«Areas currently recording the highest underwater radiated noise (URN) levels in Europe include parts of the English Channel, the Strait of Dover, the Strait of Gibraltar, sections of the Adriatic Sea, the Dardanelles Strait, and some regions of the Baltic Sea. The lowest levels are found in the northwestern Northeast Atlantic, particularly around the Denmark Strait and Irminger Sea, and the southern Mediterranean Sea.» European Maritime Transport Environmental Report 2025.

Moreover, port infrastructure is a notable source of environmental noise, as 80% of global transport occurs via shipping. However, no standardized protocols exist for measuring sound pollution from port activities.

«Port-related noise pollution, especially from container handling and ship engines, exceeds WHO-recommended limits in adjacent urban areas, increasing cardiovascular disease risks and sleep disorders among residents.» Miedema, H.M.E. & Vos, H. (1998).

Construction and machinery in cities

Construction processes and machinery used in urban works are among the top concerns for citizens’ health and well-being. Multiple noise sources exist depending on the activity, but most originate from: material transport, specific construction processes (demolition, drilling, metal cutting), and heavy machinery operation.

Effects of noise on health and the environment

The effect of noise on people’s health and the environment is a growing pollution problem, especially in cities where dense traffic levels combine with industrial activities and construction work.

According to the European Environment Agency (EEA): «Prolonged exposure to environmental noise causes 12,000 premature deaths per year and contributes to 48,000 new annual cases of ischemic heart disease. Additionally, it is estimated that 22 million people suffer from high chronic annoyance and 6.5 million people experience significant sleep disturbances. Aviation noise alone is responsible for 12,500 schoolchildren showing cognitive impairment.» Murphy, E. and King, E.A. Environmental Noise Pollution.

The environmental impact of noise, besides affecting humans, disrupts ecosystems by causing disturbances in the behavior, physiology and survival of some species, increasing environmental degradation.

Consequences for human health

Chronic exposure to noise pollution with sounds exceeding 55 dB increases the risk of developing hypertension, hearing problems, chronic stress, sleep disorders, and cardiovascular diseases. In fact, traffic noise on streets with heavy vehicle flow increases the risk of heart attacks by 8% due to oxidative stress and cortisol release which raise blood pressure.

Similarly, the lack of restorative sleep when exposed to environmental noise levels exceeding 40 dB at night affects sleep quality and is linked to the development of diabetes, obesity and depression. In fact, chronic urban noise increases the risk of anxiety disorders by 25%.

Impact on the environment and biodiversity

The effects of anthropogenic noise on ecosystems cause serious disturbances such as interfering with animals’ acoustic communication (used to warn about predators, search for food, and reproduction). It also causes a decrease in mating rates for some bird species, which affects the reduction of species diversity in noisy areas. Additionally, chronic noise causes physiological stress that increases corticosterone levels (reducing immune capacity and reproductive success) in amphibians and mammals.

The displacement of species caused by noise pollution unbalances the trophic chain, mainly due to predators abandoning certain habitats. This modifies species control and allows others, such as flora species, to develop under different distribution patterns.

In marine ecosystems, noise pollution caused by underwater drilling, ship engines and sonar disorients cetaceans. Species like whales, dolphins and orcas emit waves to feed and reproduce, and communication distortion between individuals is causing mass strandings.

Overall, the disturbances caused by noise pollution in the environment create invisible environmental degradation that nevertheless has profound and cumulative effects on biodiversity.

Regulations and noise thresholds

Legal limits for noise pollution, established through international regulations, constitute an scientific evidence-based regulatory framework to mitigate the impacts of environmental noise.

These thresholds are typically defined in dB(A) weighted according to human auditory sensitivity curves and are applied through:

• Exposure criteria: Differentiate between daytime and nighttime limits and define strategic noise maps that identify hotspots where permitted thresholds are exceeded.
• Technical controls: Establish approaches based on sound barriers with specific absorption coefficients and restrictions on mobile sources like vehicle noise emissions.

Main european and international regulations

Directive 2002/49/EC (EU)

Establishes a common framework for assessing and managing environmental noise in the EU, aiming to prevent/reduce its harmful effects on human health. It applies to road, rail and air traffic in urban areas exceeding 100,000 inhabitants and industrial zones. Its main limitations are that it doesn’t set mandatory limits (delegating this to member states) and lacks harmonized penalties for non-compliance.

WHO Community Guidelines on Noise (1999)

Sets maximum thresholds for environmental noise exposure based on epidemiological evidence of health effects. These guidelines are under revision to include low-frequency noise (like wind turbines), noise pollution’s impact on wildlife, and new standards for electric vehicles.

U.S. Environmental Protection Agency (EPA)

Regulates environmental noise through the Noise Control Act (1972) and Quiet Communities Act (1978). These laws don’t establish federally enforceable limits, having transferred primary regulatory responsibility to states and municipalities. However, the EPA suggests recommended (non-binding) levels based on scientific studies. It lacks harmonized metrics or strategic noise maps.

Recommended limits and threshold values

Exposure to sound levels exceeding 65 dB(A) or decibels weighted for human hearing sensitivity during daytime and 55 dB(A) at night is classified as noise pollution under international standards.

The WHO warns that noise sources associated with recreational activities (road traffic, entertainment venues, mass events) frequently exceed 70 dB(A) of continuous exposure, even over 24-hour cycles, violating recommended health protection limits. Epidemiological studies show this increases risks of hearing loss, sleep disorders and chronic stress.

Measurement and solutions for noise pollution control

Accurate measurement of noise or acoustic pollution is essential to manage its impact on public health and the environment. Acoustic monitoring is a key ally in ensuring compliance with noise regulations.

Existing noise measurement technologies vary in terms of accuracy, application range and economic cost.

Environmental noise measurement methods

Today, there are various systems and methods for measuring noise:

Sound level meters or decibel meters

Manual sound level meters capture sound pressure using condenser microphones. They apply frequency weighting adapted to human hearing perception. Often used in spot measurement campaigns, they require periodic calibration and are not capable of discriminating individual sound sources in complex acoustic environments.

Sound level meters, also known as decibel meters, are classified into Class 1 and Class 2 according to the IEC 61672-1 standard:

• Class 1: Stricter tolerance, designed for high-precision measurements; also specifies operating conditions and uncertainty limits.
• Class 2: Broader tolerance, intended for general environmental noise measurements. Covers a narrower frequency range and shows greater variations at the lower and higher ends. Used in urban, industrial and occupational environments not requiring maximum precision.

Technical feature	Class 1	Class 2
Accuracy	High	Moderate
Tolerance	Stricter	Less strict
Frequency range	10 Hz to 20,000 Hz	20 Hz to 8,000 Hz
Typical applications	Professional acoustic studies, legal certifications, scientific research	General environmental assessments, routine inspections, education
Operating temperature	-10°C to 50°C	0°C to 40°C

Noise dosimeters

Noise dosimeters are devices designed to measure an individual’s acoustic exposure over a specific period of time. Unlike sound level meters, which record noise levels at a fixed location and moment, dosimeters are worn on the body, typically near the ear, to assess the total noise dose received during a work shift.

In addition to evaluating occupational exposure and ensuring compliance with regulatory standards such as those from the OSHA (Occupational Safety and Health Administration) in the US and the European Directive on Noise at Work, dosimeters help to determine personalised hearing protection and enable monitoring in dynamic environments where workers move between zones with varying noise levels.

Fixed acoustic monitoring stations

Fixed acoustic monitoring stations are permanent installations designed to record and analyse noise levels in the environment continuously. Many include weather sensors to monitor temperature, humidity, wind speed and direction, allowing correlation of meteorological data with fluctuations in environmental noise.

These stations feature high-precision sound level meters that measure sound pressure across different frequency ranges. They collect real-time data which, once analysed, generates detailed reports on the variability of noise in a given area.

They are primarily used to control noise pollution in urban and industrial zones, monitor sound levels in green areas and protected natural spaces, and manage infrastructure-related noise impacts from ports, airports, and roads affecting nearby populations.

Noise spectral analysis

This method examines the distribution of frequencies in a sound signal, allowing identification of the source’s nature. For example, low-frequency noise is often linked to industrial machinery, while specific tones may indicate the presence of electrical equipment.

Spectral analysis is essential in the evaluation of noise pollution, supporting the implementation of corrective measures tailored to each type of noise.

Noise measurement through indirect observation and noise modelling

The assessment of environmental noise does not always require direct on-site measurements. There are technical approaches that allow the study of its impact and evolution using mathematical models and simulation tools. Among these, the most prominent include:

Noise mapping (or acoustic cartography)

Noise maps are graphical representations of sound levels within a specific area. They are created by combining real measurements and simulations using specialised software, allowing the visualisation of noise distribution and its evolution over time.

One of the most widely used models in Europe for generating these maps is CNOSSOS-EU (Common Noise Assessment Methods in Europe), a standardised system that incorporates various noise sources such as road, rail and air traffic for the production of strategic noise maps.

Predictive sound propagation models

Sound propagation models allow users to simulate the behaviour of noise from known sources, such as urban traffic or industrial activity. These tools consider variables like topography, weather conditions, and material absorption, offering accurate forecasts of noise levels in different scenarios.

Among the most commonly used software in this field are CadnaA, SoundPLAN, and IMMI. These tools are designed to model sound propagation and propose effective mitigation strategies.

Artificial Intelligence for automatic noise detection

Artificial Intelligence (AI) is transforming acoustic monitoring thanks to its ability to process large volumes of data in real time. Advanced algorithms, such as deep learning neural networks, can learn to recognise complex sound patterns and automatically identify noise sources — such as road traffic, industrial machinery or human activity — with increasing accuracy. These solutions not only reduce the need for manual intervention, but also enable continuous, adaptive and scalable monitoring, ideal for smart cities and industrial environments where early detection and rapid response are key to mitigating noise pollution.

Together, all these increasingly precise methods, driven by technological advances, are essential for urban planning and public health protection. They combine empirical data with computer simulations to support informed decision-making and effective noise mitigation strategies.

Emerging technologies in environmental noise measurement

In recent years, a range of digital tools have emerged to simplify the measurement and analysis of environmental noise. These tools also promote citizen participation and facilitate public access to real-time acoustic data. They enable users to contribute data they have collected themselves, helping to build collaborative noise maps and support community-led efforts to improve noise management in urban areas.

Mobile noise measurement apps

Applications such as Decibel X, Sound Meter and NoiseCapture have become popular among both citizens and professionals dealing with noise pollution. While they do not offer the accuracy of certified sound level meters, they are useful tools for raising awareness about noise pollution and recording data across various locations and times.

Thanks to their ease of use and availability on mobile devices, these apps enable anyone to quickly measure sound levels and share data through noise monitoring platforms.

Citizen science platforms

Projects such as Noise Planet, Noise Project and Sons al Balcó have developed systems that integrate user-submitted data to build participatory noise maps.

Through large-scale data collection at various locations, these initiatives make it possible to visualise the distribution of noise pollution in urban areas, identify critical zones, and develop strategies to reduce acoustic pollution.

In conclusion, these emerging technologies not only democratise access to environmental information, but also foster active public involvement in noise management, leading to more effective and sustainable solutions.

Advantages of applying technological solutions for noise control

Implementing low-cost, high-precision technological solutions like Kunak’s advanced noise measurement stations is key to proper noise pollution management. This effective solution benefits from sensor equipment precision that avoids systematic errors. Their measurements have ≤1 dB(A) uncertainty, ensuring compliance with international regulations.

Connected acoustic measurement stations

The strength of acoustic measurement stations in noise monitoring networks lies in their low energy consumption and stable, continuous transmission from remote areas. Solar-powered operation ensures prolonged autonomy.

Integration with environmental management platforms

Technology solutions based on noise measurement stations enable proper data visualization complemented by historical trends. They feature automatic alerts when predefined noise pollution thresholds are exceeded and generate reports for advanced analytics and decision-making.

Octave band calibration of acoustic stations

Octave band calibration is essential for ensuring precise noise measurements across different frequency bands. This process analyzes sound energy distribution and adjusts noise sensors to provide reliable results for informed decisions.

Noise measurement is based on frequency analysis since different noise sources have distinct spectral characteristics. Octave band calibration enables:

• Source identification: Spectrum segmentation detects specific patterns associated with various noise pollution sources.
• Precision assurance: Sensor response adjustment per band ensures measurements reliably reflect actual sound pressure.
• Regulatory compliance: Standards like EU’s IEC 61260-1:2014 regulate octave band analyzer use for high-quality data.

This calibration can be performed in the field when it is carried out directly in the measurement environment, ensuring the functionality of the sensor under real conditions. It can also be performed periodically in the laboratory at regular intervals and under controlled environment conditions to ensure the reliability of the equipment.

In short, by means of an essential tool such as octave calibration, it is possible to obtain detailed measurements that make it possible to design effective environmental noise control strategies, identify acoustic problems and design solutions to minimise their impact, as well as to guarantee regulatory compliance.

Why is noise control important?

Environmental noise control stands as a critical strategy to mitigate its adverse effects, well-documented in three key dimensions: public health, biodiversity conservation and urban sustainability. Though historically underestimated compared to other environmental risks, current scientific evidence (supported by epidemiological, environmental and acoustic studies) demands proactive, data-based management supported by advanced monitoring systems.

Benefits of implementing noise measurement and control technologies include:

Improved quality of life and public health

Beyond preventing human well-being deterioration, environmental noise control prevents pathologies like irreversible hearing loss, sleep disorders, hypertension, increased heart attack risk, mental health issues (depression, chronic stress) and associated healthcare costs.

Regulatory compliance and conflict reduction

Noise pollution mitigation strategies are fundamental for developing sustainable urban environments. Precise monitoring technology ensures compliance with current regulations, protecting public health by maintaining sound levels below adverse effect thresholds and preventing socio-environmental conflicts. This is achieved through citizen participation in solution design, public noise map availability, and transparent technical criteria for urban planning decisions.

Competitive advantage and corporate sustainability

Advanced acoustic monitoring systems represent strategic value for companies seeking business opportunities and competitiveness. Controlling noise-impacting industrial operations benefits not just public health and environment but also economy and safety. Technical rigor in noise monitoring differentiates future-oriented industries whose corporate sustainability principles form the basis of long-term business strategy.

Frequently Asked Questions about noise pollution (FAQs)

What noise levels constitute noise pollution?

According to World Health Organization (WHO) guidelines, noise pollution occurs when environmental sound levels exceed 55 dB(A) during daytime and 45 dB(A) at night in residential areas.

What are the main health effects of noise?

Prolonged noise exposure can significantly increase risks of sleep disturbances, cardiovascular stress, irreversible hearing loss, mental health problems, and cognitive impairment in children, among others.

How can environmental noise be continuously measured?

Continuous environmental noise measurement uses specialized sensor-equipped monitoring stations. These advanced technology devices comply with international standards and feature precise microphones recording sound levels 24/7. Data is automatically transmitted to centralized platforms analyzing key parameters like sound levels, noise peaks and regulatory indicators. They generate updated noise maps, provide immediate alerts when legal limits are exceeded, and predict problematic situations through acoustic models. This technology offers valuable information for informed decisions and environmental noise regulation compliance.

What regulations govern noise pollution in Europe?

Directive 2002/49/EC is the primary legal instrument for environmental noise management in the European Union. Binding for all member states, it establishes an innovative approach based on three pillars: assessment, management and prevention of noise pollution.

Its most valuable technical aspect requires strategic noise maps for all urban areas exceeding 100,000 inhabitants, plus major transport infrastructures (roads, railways, airports) and large industrial facilities.

What solutions exist for noise pollution control in cities or industries?

Cities and industries now have advanced technologies for efficient noise pollution control. Smart sensors installed at strategic points measure noise 24/7, transmitting data to digital platforms. These cloud-based systems enable real-time noise level visualization on interactive maps, identifying critical areas.

Beyond monitoring, active solutions include acoustic barriers with absorbent materials, special pavements reducing traffic noise, and early warning systems for legal limit exceedances. Industrial settings use soundproof cabins and predictive machinery maintenance to minimize vibrations and disruptive noises.

Conclusion

Though invisible, noise pollution poses serious threats to human health and ecosystem balance. Its harmful effects demand immediate, effective action. Fortunately, we now have accessible, technologically advanced solutions for comprehensive challenge management. Low-cost noise sensors, real-time monitoring systems and innovative soundproofing materials not only facilitate regulatory compliance but also promote healthier environments. In urban and industrial contexts, these technologies, complemented by smart planning strategies, demonstrate that economic development can coexist with social and environmental well-being through proactive noise management.

Sources

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• Acoustic and noise control. R.S. Peters et al., 2015. https://doi.org/10.4324/9781315847146
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