June 21, 2024

Noise pollution is a growing concern in our increasingly urbanized world. From the constant hum of traffic to the blaring sounds of construction sites, noise can have a significant impact on our daily lives. But what are acceptable noise levels? How much noise is too much? In this comprehensive guide, we will explore the different types of noise, the impacts of noise pollution, and the guidelines for acceptable noise levels. We will also delve into the legal frameworks that regulate noise levels and the technologies available to measure and mitigate noise. So, let’s dive in and discover how to create a more peaceful and harmonious environment for all.

What are Noise Levels?

Definitions and Measurements

Noise levels refer to the amount of unwanted sound or background noise present in a given environment. It is measured in decibels (dB) and can be described as the intensity of a sound wave. There are various ways to measure noise levels, including sound level meters, dosimeters, and octave band analyzers. These tools help determine the noise exposure of an individual and provide insight into the impact of noise on human health and safety. Understanding the different measurement methods and the corresponding decibel levels is crucial in determining acceptable noise levels in various settings, such as workplaces, residential areas, and public spaces.

Types of Noise

There are various types of noise that can impact the quality of sound and communication. These types of noise include:

  1. Physical Noise: This type of noise is caused by external physical factors such as temperature, humidity, and vibrations. It can affect the quality of sound and cause distortion or interference.
  2. Mechanical Noise: This type of noise is caused by mechanical factors such as friction, vibration, and resonance. It can be present in machinery, vehicles, and other mechanical systems.
  3. Electromagnetic Noise: This type of noise is caused by electromagnetic interference, which can affect the quality of sound and communication. It can be present in electronic devices, power lines, and other electrical systems.
  4. Acoustic Noise: This type of noise is caused by sound waves that can impact the quality of sound and communication. It can be present in background noise, echoes, and reverberation.
  5. Psychological Noise: This type of noise is caused by psychological factors such as stress, fatigue, and distraction. It can affect the ability to concentrate and focus on sound and communication.

It is important to understand the different types of noise as they can impact the quality of sound and communication in different ways. Identifying the source of noise and implementing appropriate measures to mitigate it can help improve the quality of sound and communication.

Standards and Regulations

Key takeaway: Understanding acceptable noise levels is crucial in determining the appropriate noise control measures in various settings, such as workplaces, residential areas, and public spaces. Excessive noise exposure can lead to health problems and legal consequences. It is important to consider the different types of noise, personal and health factors, and legal implications when determining acceptable noise levels. Passive and active noise control techniques, as well as noise-reducing equipment, can be used to monitor and reduce noise levels. Educating employees and communities, encouraging proper noise management practices, and seeking resources and support can also help create a safe and healthy sound environment.

Occupational Safety and Health Administration (OSHA)

The Occupational Safety and Health Administration (OSHA) is a US government agency responsible for setting and enforcing workplace safety and health standards. OSHA’s noise exposure limits are designed to protect workers from the harmful effects of excessive noise exposure in the workplace.

According to OSHA, the permissible exposure limit (PEL) for noise in the workplace is 90 decibels (dB) as an 8-hour time-weighted average (TWA). This means that workers should not be exposed to noise levels above 90 dB for more than 8 hours per day, as this can lead to hearing loss and other health problems.

OSHA also requires employers to provide hearing protection to workers who are exposed to noise levels above 85 dB for extended periods of time. Employers must also provide training to workers on the hazards of noise exposure and how to properly use hearing protection.

In addition to the PEL, OSHA has also established a set of general industry noise standards that cover a wide range of industries, including manufacturing, construction, and service industries. These standards set specific requirements for noise control methods, such as enclosing or isolating noisy equipment, and providing hearing protection to workers.

Employers are responsible for conducting noise surveys to identify areas of high noise exposure and implementing appropriate controls to reduce noise levels. Failure to comply with OSHA’s noise standards can result in fines and penalties, as well as legal action from workers who have been adversely affected by excessive noise exposure.

Overall, OSHA’s noise exposure limits and standards play a crucial role in protecting workers from the harmful effects of excessive noise exposure in the workplace. By following these guidelines, employers can ensure a safe and healthy work environment for their employees, while also complying with legal requirements.

Environmental Protection Agency (EPA)

The Environmental Protection Agency (EPA) is a government agency in the United States responsible for protecting human health and the environment. The EPA establishes and enforces regulations related to noise pollution, with the goal of minimizing the negative impacts of noise on the environment and public health.

One of the key regulations established by the EPA is the National Ambient Air Quality Standards (NAAQS), which sets standards for the maximum allowable levels of pollutants in the air, including noise. The NAAQS is designed to protect public health and the environment from the harmful effects of air pollution, including noise pollution.

Under the NAAQS, the EPA has established specific noise level standards for different types of land uses, including residential, commercial, and industrial areas. These standards are designed to ensure that noise levels do not exceed certain levels that are considered safe for human health and the environment.

The EPA also provides guidance and resources for states and localities to help them develop and implement noise control programs. This includes funding for research, technical assistance, and training, as well as the development of educational materials and outreach programs to raise awareness about the impacts of noise pollution and how to reduce it.

Overall, the EPA plays a critical role in regulating noise pollution in the United States, working to protect human health and the environment from the harmful effects of excessive noise.

World Health Organization (WHO)

The World Health Organization (WHO) is a specialized agency of the United Nations responsible for promoting health, keeping the world safe, and serving the vulnerable. The WHO sets international standards for health-related issues, including noise pollution. In 1999, the WHO introduced the “Guidelines for Community Noise” which provides recommendations for the acceptable levels of environmental noise. These guidelines aim to protect human health and well-being by limiting the impact of noise pollution on communities.

The WHO guidelines recommend that outdoor noise levels should not exceed 60 decibels (dB) during the day and 55 dB at night. Additionally, the guidelines state that the average noise level in residential areas should not exceed 55 dB during the day and 45 dB at night. The guidelines also provide recommendations for the acceptable levels of noise in different types of environments, such as schools, hospitals, and workplaces.

The WHO guidelines have been widely adopted by many countries and have become the standard for assessing and controlling noise pollution. The guidelines have been revised several times to incorporate new research and to provide more detailed recommendations for specific types of noise sources.

Factors Affecting Acceptable Noise Levels

Indoor Environment

  • Internal Factors:
    • Design of the Space: The design of the indoor space, including the layout, materials used, and the presence of noise barriers, can significantly impact the acceptable noise levels. For example, a room with hard surfaces like concrete and tile floors will have higher noise levels compared to a room with carpeting.
    • Activity Level: The level of activity within the indoor space can also impact acceptable noise levels. For instance, a library with minimal activity may have lower acceptable noise levels compared to a busy office.
    • Number of People: The number of people present in the indoor space can also impact acceptable noise levels. In general, the more people present, the higher the acceptable noise level.
  • External Factors:
    • Outdoor Noise: Outdoor noise levels can also impact acceptable noise levels within an indoor space. For example, a room near a busy street may have higher acceptable noise levels compared to a room further away from the street.
    • Mechanical Systems: Mechanical systems such as HVAC systems, elevators, and generators can also contribute to the acceptable noise levels within an indoor space. For example, a room near a noisy HVAC system may have higher acceptable noise levels compared to a room further away from the system.

Outdoor Environment

The acceptable noise levels in an outdoor environment are determined by a variety of factors. One of the main factors is the time of day. During the day, noise levels are generally higher due to increased activity and the presence of more people. In contrast, at night, noise levels tend to be lower, except for areas with high traffic or other sources of noise.

Another important factor is the location of the outdoor environment. For example, noise levels in a park may be higher than in a residential area due to the presence of children playing and other activities. Additionally, the type of outdoor environment can also impact noise levels. For example, a construction site will have higher noise levels than a nature reserve.

It is important to note that the acceptable noise levels in an outdoor environment can also be affected by local regulations and laws. Some areas may have specific noise limits that must be adhered to in order to prevent disturbance to residents or other individuals in the area.

Furthermore, the purpose of the outdoor environment can also play a role in determining acceptable noise levels. For example, a music festival may have higher noise levels than a peaceful park.

In conclusion, the acceptable noise levels in an outdoor environment are influenced by a range of factors, including time of day, location, type of environment, and local regulations. It is important to consider these factors when determining the appropriate noise levels for any given outdoor space.

Personal and Health Factors

  • Sensitivity to noise: Some individuals are more sensitive to noise than others, and this can affect their perception of acceptable noise levels. Factors such as age, hearing loss, and anxiety or stress can contribute to increased sensitivity to noise.
  • Comfort levels: Personal preferences and comfort levels can also play a role in determining acceptable noise levels. For example, some people may find background music relaxing, while others may find it distracting.
  • Health impacts: Excessive noise levels can have negative impacts on physical and mental health. Prolonged exposure to loud noise can lead to hearing loss, stress, anxiety, and sleep disturbances. Therefore, it is important to consider health factors when determining acceptable noise levels.
  • Environmental factors: The environment in which noise is occurring can also impact acceptable noise levels. For example, noise levels in a busy city may be higher than in a quiet suburban neighborhood. The time of day and the activity being conducted can also impact acceptable noise levels.

Monitoring and Reducing Noise Levels

Noise Control Techniques

Controlling noise levels is an essential aspect of maintaining a healthy and productive environment. Several noise control techniques can be employed to minimize the impact of noise on individuals and communities. In this section, we will discuss some of the most effective noise control techniques.

Passive Noise Control
Passive noise control involves designing and constructing buildings and structures to minimize the transmission of noise. This approach involves using materials with high sound-absorbing qualities, such as carpets, curtains, and acoustic ceiling tiles, to reduce the impact of noise on occupants. Other passive noise control techniques include the use of soundproofing materials, such as mass-loaded vinyl, and the strategic placement of furniture and fixtures to absorb or block noise.

Active Noise Control
Active noise control involves the use of technology to actively reduce noise levels. This approach typically involves the use of sound-cancelling headphones or noise-cancelling technology in buildings and structures. Active noise control systems work by generating a sound wave that is out of phase with the noise, effectively cancelling it out.

Operational Noise Control
Operational noise control involves changing the way equipment and machinery are operated to reduce noise levels. This approach can involve changing the speed or direction of equipment, enclosing machinery, or using vibration isolation systems. Operational noise control techniques can be highly effective in reducing noise levels in industrial and manufacturing settings.

Administrative Noise Control
Administrative noise control involves changing work practices and schedules to reduce noise exposure. This approach can involve staggering shifts, rotating job tasks, or providing earplugs and other hearing protection devices to workers. Administrative noise control techniques can be highly effective in reducing noise exposure in noisy workplaces.

Overall, a combination of these noise control techniques can be used to effectively reduce noise levels in various settings. It is essential to understand the benefits and limitations of each technique and to choose the most appropriate approach for the specific situation.

Acoustic Materials and Treatments

In order to effectively monitor and reduce noise levels, it is important to understand the role that acoustic materials and treatments play in managing sound transmission. These materials and treatments can help to absorb, reflect, or diffuse sound waves, reducing the amount of noise that is transmitted through walls, floors, and ceilings.

Some common types of acoustic materials and treatments include:

  • Drywall: Regular drywall is not particularly effective at blocking sound transmission, but specialty drywall products, such as those with added sound-blocking layers, can be more effective.
  • Acoustic ceiling tiles: These tiles are designed to absorb sound waves and can be installed in suspended ceilings to help reduce noise transmission.
  • Sound-absorbing panels: These panels can be attached to walls or ceilings and are designed to absorb sound waves, reducing echo and reverberation.
  • Acoustic curtains: These curtains are made from materials that are designed to absorb sound waves and can be hung on windows or doors to help reduce noise transmission.
  • Reflective surfaces: Reflective surfaces, such as mirrors or foil-backed insulation, can be used to reflect sound waves and reduce noise transmission.

In addition to these materials, there are also a variety of treatments that can be applied to surfaces to improve their sound-blocking properties. These treatments can include adding mass to walls or ceilings, installing resilient channels, or applying sound-blocking coatings.

When selecting acoustic materials and treatments, it is important to consider the specific needs of the space and the type of noise that is being transmitted. Some materials and treatments may be more effective at blocking low-frequency sounds, while others may be better suited for high-frequency sounds. It is also important to consider the cost and installation requirements of each option.

Noise-Reducing Equipment

Reducing noise levels is a critical aspect of ensuring a comfortable and healthy environment. Various noise-reducing equipment is available in the market that can help minimize noise pollution. This section will explore the different types of noise-reducing equipment that can be used to monitor and reduce noise levels.

Types of Noise-Reducing Equipment

There are several types of noise-reducing equipment that can be used in different settings. Some of the most common types of noise-reducing equipment include:

  1. Soundproofing Materials: These materials are designed to absorb or block sound waves, reducing the amount of noise that enters or leaves a room. Examples of soundproofing materials include acoustic panels, soundproofing insulation, and soundproofing drywall.
  2. Noise-Canceling Headphones: These headphones use advanced technology to cancel out external noise, making them ideal for use in noisy environments such as airports or construction sites. They work by using microphones to pick up external noise and then generate an opposite sound wave to cancel it out.
  3. White Noise Machines: These machines emit a consistent, low-level noise that can help drown out other sounds. They are often used in bedrooms or nurseries to help people sleep better.
  4. Acoustic Curtains: These curtains are made from a special material that helps absorb sound waves, making them ideal for use in noisy rooms such as bedrooms or living rooms.
  5. Noise-Reducing Earplugs: These earplugs are designed to block out external noise, making them ideal for use in noisy environments such as construction sites or concerts. They come in different sizes and styles, including disposable and reusable options.

Benefits of Noise-Reducing Equipment

Using noise-reducing equipment has several benefits, including:

  1. Improved Health and Wellbeing: Exposure to excessive noise levels can lead to stress, anxiety, and other health problems. Using noise-reducing equipment can help reduce the risk of these health problems.
  2. Increased Productivity: Noise can be a major distraction, making it difficult to concentrate and be productive. Using noise-reducing equipment can help reduce distractions and improve productivity.
  3. Better Sleep: Excessive noise levels can disrupt sleep patterns, leading to insomnia and other sleep disorders. Using noise-reducing equipment can help create a more peaceful and relaxing environment, improving sleep quality.
  4. Enhanced Safety: In some settings, such as construction sites or industrial facilities, excessive noise levels can pose a safety risk. Using noise-reducing equipment can help reduce the risk of accidents and injuries.

In conclusion, using noise-reducing equipment is an effective way to monitor and reduce noise levels in different settings. From soundproofing materials to noise-canceling headphones, there are several types of equipment available that can help create a more comfortable and healthy environment.

Legal Implications of Excessive Noise

Liability and Compensation

Excessive noise can have legal implications, particularly in situations where it infringes on an individual’s right to enjoy their property without undue disturbance. In such cases, the party responsible for the noise may be held liable for any damages or compensation resulting from the noise.

In many jurisdictions, there are laws and regulations that establish acceptable noise levels and specify the responsibilities of individuals and businesses to minimize noise pollution. These laws may also provide for penalties and fines for those who violate noise regulations.

When it comes to liability and compensation, the party responsible for the excessive noise may be held accountable for any damages or harm caused to the affected individual or property. This may include compensation for lost property value, reduced quality of life, and medical expenses related to health problems caused by excessive noise.

It is important to note that the burden of proof in such cases lies with the affected individual, who must demonstrate that the excessive noise was the direct cause of the harm or damages suffered. This may require gathering evidence such as noise measurements, witness statements, and medical records to support the claim.

Additionally, in some cases, the affected individual may be required to pursue legal action against the responsible party in order to seek compensation for damages. This may involve filing a lawsuit or pursuing other legal remedies.

Overall, the legal implications of excessive noise can be complex and varied. It is important for individuals to understand their rights and the laws and regulations that apply in their jurisdiction in order to protect themselves from excessive noise and seek compensation when necessary.

Penalties and Enforcement

In many jurisdictions, excessive noise is regulated by law, and there are penalties for those who violate these regulations. These penalties can include fines, court orders, and even criminal charges. In addition to penalties, there are also enforcement measures in place to ensure that noise levels remain within acceptable limits.

Types of Enforcement Actions

There are several types of enforcement actions that can be taken when excessive noise is reported. These include:

  • Informal enforcement: This is the least formal type of enforcement and may involve a warning or education from a local noise control officer.
  • Formal enforcement: This type of enforcement involves a more formal process, such as a notice of violation or a court order.
  • Legal action: In some cases, legal action may be taken against those who violate noise regulations. This can include fines, penalties, or even criminal charges.

Fines and Penalties

The amount of the fine or penalty for excessive noise violations varies depending on the jurisdiction and the severity of the violation. In some cases, the fine may be a set amount, while in others it may be determined based on the specific circumstances of the violation. Some jurisdictions also have penalties for repeat offenders, which may result in higher fines or other consequences.

Court Orders

In some cases, a court order may be issued to those who violate noise regulations. These orders may require the person to take specific actions to reduce the noise level, such as installing soundproofing or limiting the hours of operation for a business. Failure to comply with a court order can result in additional penalties, including fines or even imprisonment.

Criminal Charges

In some cases, excessive noise violations may result in criminal charges. These charges can vary depending on the jurisdiction and the severity of the violation, but they can include misdemeanors or even felonies. In addition to fines and penalties, criminal charges can also result in imprisonment.

In conclusion, excessive noise violations can have serious legal consequences, including fines, penalties, court orders, and even criminal charges. It is important for individuals and businesses to understand the legal implications of excessive noise and to take steps to ensure that they are in compliance with noise regulations.

Creating a Safe and Healthy Sound Environment

Educating Employees and Communities

Proper education and training on noise-related issues are essential for employees and communities to understand the impact of noise on their health and safety. This section will discuss the importance of educating employees and communities and how it can contribute to creating a safe and healthy sound environment.

Educating employees and communities can help them identify noise hazards and understand the risks associated with excessive noise exposure. By providing training on noise-related topics, such as noise measurement, hearing protection, and noise control methods, employees and communities can learn how to reduce noise exposure and prevent hearing loss.

Moreover, education can also promote a culture of awareness and responsibility towards noise control, where individuals take an active role in creating a safe and healthy sound environment. This can include simple actions such as closing doors to minimize noise transfer, using noise-absorbing materials, and reducing the use of noisy equipment during quieter hours.

It is important to involve employees and communities in the noise management process to ensure that their needs and concerns are addressed. By engaging them in the decision-making process, employers and communities can develop effective noise control strategies that are practical and sustainable.

In addition, education can also help dispel misconceptions and myths about noise and hearing loss, such as the belief that hearing loss is an inevitable part of aging. By providing accurate information and raising awareness, individuals can take proactive steps to protect their hearing and prevent noise-induced hearing loss.

Overall, educating employees and communities is a crucial step towards creating a safe and healthy sound environment. By promoting awareness and understanding of noise-related issues, individuals can take an active role in reducing noise exposure and preventing hearing loss.

Encouraging Proper Noise Management Practices

Encouraging proper noise management practices is essential for creating a safe and healthy sound environment. Here are some steps that can be taken to achieve this goal:

  1. Education and Awareness
    • Educate employees about the potential health effects of noise exposure and the importance of proper noise management practices.
    • Provide training on how to use noise-control equipment and personal protective devices effectively.
    • Encourage workers to report any hearing problems or other health issues related to noise exposure.
  2. Noise Assessment and Monitoring
    • Conduct regular noise assessments to identify areas where noise levels may be too high.
    • Install noise-monitoring equipment to continuously measure noise levels in the workplace.
    • Use the data collected from noise assessments and monitoring to develop strategies for reducing noise exposure.
  3. Noise Control Strategies
    • Implement engineering controls, such as enclosing or isolating noisy equipment, to reduce noise at the source.
    • Use administrative controls, such as rotating workers between noisy and quiet tasks, to reduce noise exposure.
    • Provide personal protective equipment, such as earplugs or earmuffs, to workers who are exposed to high levels of noise.
  4. Establishing Noise Limits and Guidelines
    • Establish noise limits and guidelines based on industry standards and regulatory requirements.
    • Ensure that noise limits are regularly reviewed and updated to reflect changes in the workplace.
    • Communicate noise limits and guidelines to all employees and enforce them consistently.
  5. Communication and Cooperation
    • Encourage open communication between management and workers about noise-related issues.
    • Create a culture of cooperation where workers feel comfortable reporting noise-related problems and suggesting solutions.
    • Recognize and reward workers who demonstrate good noise management practices.

By following these steps, organizations can encourage proper noise management practices and create a safe and healthy sound environment for their employees.

Resources and Support

For individuals looking to create a safe and healthy sound environment, there are several resources and support options available. These resources can provide valuable information on how to reduce noise levels, prevent hearing damage, and promote better listening habits.

Professional Consultation

One of the most effective ways to ensure a safe and healthy sound environment is to consult with a professional. This can include an acoustician, audiologist, or other noise control specialist. These professionals have the expertise and experience to assess your specific sound environment and provide tailored recommendations for improvement. They can also help identify potential hazards and provide guidance on how to mitigate them.

Online Resources

There are many online resources available that can provide valuable information on acceptable noise levels and how to create a safe and healthy sound environment. Websites such as the World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC), and the National Institute for Occupational Safety and Health (NIOSH) provide detailed information on noise-induced hearing loss, recommended noise exposure limits, and best practices for reducing noise levels.

Additionally, there are many online forums and communities dedicated to discussing sound-related topics. These forums can provide valuable insights and advice from individuals who have faced similar challenges in creating a safe and healthy sound environment.

Educational Resources

Educational resources such as books, articles, and courses can also provide valuable information on acceptable noise levels and how to create a safe and healthy sound environment. These resources can help individuals understand the science behind sound and hearing, as well as provide practical tips and strategies for reducing noise levels and preventing hearing damage.

In conclusion, there are many resources and support options available for individuals looking to create a safe and healthy sound environment. Whether it’s through professional consultation, online resources, or educational materials, there is a wealth of information available to help individuals understand acceptable noise levels and take steps to promote better listening habits.

Continuous Improvement and Adaptation

In order to maintain a safe and healthy sound environment, it is essential to adopt a proactive approach to continuous improvement and adaptation. This involves regularly monitoring and assessing the effectiveness of existing noise control measures, as well as being prepared to implement new strategies in response to changing circumstances.

Continuous improvement and adaptation may involve:

  • Regularly reviewing and updating noise control plans and policies to ensure they remain relevant and effective.
  • Implementing new technology or equipment to improve noise reduction efforts.
  • Conducting regular noise surveys to identify areas where noise levels may be exceeding acceptable limits.
  • Providing training and education to employees and contractors on best practices for noise reduction and control.
  • Encouraging feedback and input from employees and other stakeholders to identify areas for improvement.

By adopting a continuous improvement and adaptation approach, organizations can ensure that they are always working towards creating a safer and healthier sound environment for their employees and the surrounding community.

FAQs

1. What are acceptable noise levels?

Acceptable noise levels refer to the amount of noise that is considered safe and acceptable in a given environment. These levels are typically established by government agencies and regulations, and can vary depending on the context, such as the workplace, residential areas, and public spaces. The acceptable noise levels are usually measured in decibels (dB) and are based on guidelines and standards set by organizations such as the World Health Organization (WHO) and the International Council for Local Environmental Initiatives (ICLEI).

2. What are the common sources of noise?

Noise can come from a variety of sources, both natural and man-made. Common sources of noise include traffic, construction sites, industrial equipment, aircraft and train noise, and household appliances. In addition, human activities such as talking, singing, and footsteps can also produce noise. The level of noise generated by these sources can vary depending on factors such as distance, duration, and the type of activity.

3. How are noise levels measured?

Noise levels are typically measured in decibels (dB), which is a logarithmic unit that expresses the ratio of the power of a sound wave to a reference level. The reference level is usually defined as the threshold of human hearing, which is approximately 0 dB for a healthy adult. Noise levels are measured using a sound level meter, which can measure the sound pressure level (SPL) in dB. The SPL is the amount of sound pressure that is generated by a sound wave, and it is measured in dB relative to a reference value.

4. What are the guidelines for acceptable noise levels?

The guidelines for acceptable noise levels vary depending on the context and the type of noise. For example, the WHO recommends that the maximum allowed noise level in residential areas should not exceed 55 dB during the day and 40 dB at night. In the workplace, the acceptable noise level may be higher, depending on the type of work and the level of noise exposure. In general, the guidelines for acceptable noise levels are based on the principle of avoiding excessive noise exposure, which can lead to hearing loss, sleep disturbance, and other health problems.

5. How can I reduce noise levels in my environment?

There are several ways to reduce noise levels in your environment, both indoors and outdoors. For example, you can use soundproofing materials such as curtains, carpets, and acoustic panels to absorb noise. You can also use noise-cancelling headphones or earplugs to block out noise. In addition, you can reduce noise levels by using quieter appliances and equipment, or by placing them in a location that minimizes noise transmission. Finally, you can limit noise exposure by reducing the amount of time you spend in noisy environments, or by taking breaks to allow your ears to recover from excessive noise exposure.

Acceptable Noise Level (ANL)

Leave a Reply

Your email address will not be published. Required fields are marked *