Global 
United States 
What is Noise Monitoring?
Some of the industries, including the manufacturing sector, are often laden with characteristic loud equipment and machinery, thus rendering them is the primary contributor for exposure to occupational noise. Industrial noises are described with various metrics, such as range of intensity or sound level between 70 and 130 decibel A-weighted (dBA), low, mid, or high frequency components, and continuous, intermittent, tonal or impulsive durations. This not only leads to serious worker health implications, reduced productivity, and challenges to overall workplace safety, especially in the case of small and medium-sized manufacturing enterprises (SMEs).
Noise control and monitoring is basically the process of measuring sound intensity in particular regions such as manufacturing plants or factories to determine whether the level of noise exceeds the acceptable limits of those specific areas. IT solutions for manufacturing and practices such as these protect plant workers from various detrimental effects of being exposed to industrial noises of high intensity and frequency for longer durations.
The market for noise pollution monitoring system is currently valued at about US $6.7 billion as of 2025 and is projected to increase up to US $10.8 billion by 2035, surging at a CAGR of about 4.8%. In this blog, we will delve into the various hazards associated with noise control in the manufacturing sector, noise control regulations, best practices and strategies for the same, and their benefits in the Health, Safety and Environment (HSE) domain.
Source: Market Research Future
Growing market size of noise and vibration monitoring systems from 2018 to 2032 forecast period
Characteristics of Industrial Noise
Given below is a brief note on some of the characteristics of industrial noise, depending on their sources.
Intensity or Sound Level
1. Low Noise: The range of sound level of such equipment ranges from 70 to 85 dB and a few examples include reciprocating air or rotary screw compressors, hydraulic injection molders, powered roller conveyor belts, etc.
2. Moderate Noise: The range of sound level of such equipment ranges from 85 to 100 dB and a few examples include linear or circular vibrating screens, high-powered induction or squirrel cage electric motors, vertical or horizontal milling machines, plastic or metal extruders, Raymond or vertical roller mills, lathe or Computer Numerical Control (CNC) machines for cutting, drilling, and milling, and other electronics manufacturing solutions.
3. High Noise: The range of sound level of such equipment ranges from 100 to 115 dB and a few examples include pneumatic punch and stamping presses, industrial diesel generators, surface or cylindrical grinders, impact or shredder hammer mills for crushing, grinding, and pulverizing, etc.
4. Very High Noise: The range of sound level of such equipment ranges from 115 to 130 dB and a few examples include drop or pneumatic forging hammers, etc.
5. Extremely High Noise: The range of sound level of such equipment exceeds 130 dB. They usually require noise monitoring and reduction, and some of the examples include electric arc or basic oxygen blast furnaces, etc.
Duration
1. Continuous Noise: These are stable sounds emitted from machinery like engines, crushers, and conveyor belts that operate or conduct processes in a continuous manner. These can last from several minutes to several hours, depending upon the operational procedures.
2. Impact Noise: This type of noise is characterized by fluctuation, that is a short and significant elevation in sound levels while lasting for only a few seconds. Commonly known as impulsive noise, this is usually generated by hydraulic hammers, mechanical presses, etc.
3. Tonal Noise: This type of noise is usually generated by industrial or mining fans that emit a specific tone as the acoustic energy is centered around frequencies.
4. Intermittent Noise: Characteristics of this type of noise include periods of inactivity alternating with periods of sound. It is generally produced when certain equipment and machinery like tracked excavators, starts and stops and showcases sporadic activities. Such sounds last from seconds to minutes at a time.
Noise Hazards
There are various hazards caused due to prolonged exposure to sounds of high intensities in the absence of industrial noise monitoring, including high psychological stress levels, temporary hearing impairment and tinnitus, increased anxiety, depression, elevated heart rate, discomfort, frustration, increased blood pressure, and more. Impulsive sounds such as that of hammering and the starting noise of machinery can also be damaging since they often exceed safe levels of exposure almost instantaneously. At times, industrial noise leads to permanent hearing loss if related concerns are not addressed immediately. This occurs when short bursts of extremely high noises damage the hair cells of the inner ear causing irreversible impairment.
Furthermore, continuous noises are capable of desensitizing workers towards a false sense of security over time. These lead to declining job satisfaction, productivity, increased levels of fatigue, likelihood of errors, lack of concentration and focus, reduced cognitive performance, delayed task completion, difficulty delivering tasks that require attention to detail and precision, etc. Apart from affecting health parameters, efficiency of operations and workplace safety are impacted multifold in noisy environments. Many a times, plant workers may miss necessary signals for safety and verbal instructions which causes mis-happenings and accidents. There may also be delays in responding to emergencies due to the inability to retrieve warning alarms efficiently and a decrease in collaboration and teamwork.
Steps for Implementing Industrial Noise Monitoring
Let us start with a few systematic approaches and best-considered implementation practices for effective and comprehensive vibration and noise monitoring.
1. Setting Objectives: Manufacturing organizations such as medical device contract manufacturing need to define clear and concise objectives by determining key factors. These include the purpose of monitoring, expected and acceptable noise and vibration levels in the specific region, existing noises present in the surrounding environment, compliance limits and their criteria, underground infrastructures such as sewers and gas lines, high-risk areas such as medical equipment, heritage buildings, labs, server rooms, and more. This helps them to plan risk mitigation techniques and appropriate implementation measures in case thresholds are exceeded.
2. Equipment Selection & Calibration: Companies need to select instruments that meet the specific needs of the site, manufacturing plant or project. This includes choosing the same as per set criteria like accuracy, reliability, portability, usability, ease, and features required for project completion. Devices must measure sound levels in Equivalent Continuous Noise Level (Leq) and Maximum Noise Level (Lmax).
3. Implementation & Maintenance: The selected sound control equipment such as noise barriers, enclosures, etc. is implemented to negate the escape of sounds to the surrounding environment. The machinery must be maintained periodically through systems for defect detection in manfuacturing, such that it operates silently and efficiently within a specific time duration. Proper documentation of the same must be registered with the local authorities as per functional data obtained.
4. Staff Training: Industrial noise monitoring requires apt technical skills for interpreting data, understanding warnings, and implementing mitigation strategies. It is necessary to train operating staff in this context to ensure accurate and timely measurements, data monitoring, and actions.
Workflow of noise and vibration monitoring systems in manufacturing plants
Types of Sound Monitoring & Control Strategies
The Central Pollution Control Board (CPCB) has defined acceptable sound levels for specific regions considering public health, the surrounding regional environment, and quality of life. The limits were 40 dB(A) during nighttime (10 p.m. to 6 a.m.) to 50 dB(A) during daytime (6 a.m. to 10 p.m.) for silence zones like hospitals and schools, 45 dB(A) to 55 dB(A) for residential areas, 50 dB(A) to 60 dB(A) for mixed zones, 55 dB(A) to 65 dB(A) for commercial areas, and 70 dB(A) to 75 dB(A) for industrial areas and manufacturing plants. Various administrative, engineering, and approaches related to Personal Protective Equipment (PPE) are being applied to mitigate noise levels in manufacturing setups which have been discussed in this section.
Other organizations such as the Occupational Safety and Health Administration (OSHA) in the U.S. and European Agency for safety and Health at Work (EU-OSHA) have imposed permissible limits of exposure to noise monitoring levels as a part of auditory regulations. The former has set standard or safe exposure limit of 90 dB(A) over an 8-hour workday, while the National Institute for Occupational Safety and Health (NIOSH) recommends a maximum of 85 dB(A) over this duration. Any worker exposed to noises of a level above 95 dB(A) requires hearing protection. Exposure to sound levels that are 100 dB(A) for more than 2 hours and 110 dB(A) for more than 30 minutes is considered hazardous to health.
Monitoring Devices
Particularly in a manufacturing setting, dosimeters and sound level meters are used to assess and map noise levels. Sound level meters measure sound intensity at specific points of time and are portable devices. They are used to provide detailed assessments and on-the-spot checks within a particular workspace, area or machinery. Dosimeters are wearable devices that continuously monitor and comprehensively assess the cumulative exposure to noise over a period such as a specific worker shift, etc. This determines if the workers are at risk of any health issues or hearing damage. These devices can help understand average and peak levels of noise for occupational safety and compliance standards.
Infrastructure Control
Modifications in the machinery such as installation of mufflers and silencers reduce the emissions of sound. As discussed earlier, equipment like compressors, exhaust systems, and motors can generate high-frequency and intensity sounds which can be absorbed by silencers prior to releasing into the environment. Machines that cause vibrations are another source of noise, as these can transfer through shop floor levels, structures, and walls. The transmission of vibrations and the consequent noise levels can be dampened through machinery isolation, use of rubber mounts, and effective AI defect detection.
Sound-reducing or soundproof enclosures for machines used for label inspection and more are other methods of sound monitoring and reduction that can lower noise levels and prevent them from escaping into the environment. Sound walls, curtains, acoustic guards, constrained layer dampening for chiller panels, isolation pads, power press and hydraulic power pack noise control, aerodynamic noise reduction for dryer fan noise, silencing techniques for pneumatic exhausts, reduced energy noise control techniques for pneumatic nozzle noise, and other barriers positioned in a strategic manner can contain noise or redirect it away from workplaces and employees.
Personal Protective Equipment
Various Personal Protective Equipment (PPE) can be used for protection from hearing damage in areas of high noise levels. These may include small earplugs that are inserted into the external auditory canal and earmuffs that fit over the worker’s ears to block external noise by creating a seal. Either of these PPE can be selected as per the exposure to noise level, workers’ comfort, and nature of tasks.
Concise and clear guidelines stating instructions of how and when to use PPE must be imposed by SMEs. The workers must be trained regarding the same, considering important factors like proper fit, IoT for predictive maintenance, and the importance for exposure risk mitigation. There should be continuous checks for maintenance to ensure that equipment performs as per their standards.
Various techniques of noise and vibration monitoring in manufacturing plants
Smart Manufacturing
Various advanced smart manufacturing tools for noise control such as Internet of Things-powered noise cancellation systems through IoT development services, and Active Noise Control (ANC) systems that can cancel unwanted noise and sound waves. These are emerging technologies featured in consumer electronics such as headphones and can be adapted for industrial applications. Increasing the affordability of such controllers can negate the large-scale shifting of heavy machinery that generates high levels of noise.
Real-time noise pollution monitoring systems or industrial noise detectors which are sensors integrated into machinery, workspace infrastructure, and equipment to measure Sound Pressure Levels (SPL), are becoming accessible. These trigger alerts during continuous monitoring, as and when the functional limit of any machinery or equipment exceeds safety standards. Furthermore, patterns of noise generation can be analyzed using cost-effective and data-driven machine learning algorithms for detecting specific sources and precautionary measures.
Environmental Control
The workspace environment and layout can be changed through acoustic treatment, that is with the addition of soundproofing material over floors, ceilings, and walls. These may include fiberglass insulation, mass-loaded vinyl, and acoustic foam that can absorb sound waves, reduce noise propagation and reverberation which cause high sound intensities and noise. Reflective hard surfaces that amplify and reflect noise must be minimized. These can be supported with carpets, curtains, acoustic tiles, and other soft and absorbent surfaces over machines monitored through a vision inspection system.
The factory layout or facility can be optimized by arranging machines and workstations or implementing operator cabins, such that the workers are minimally exposed to high intensities of noise. Designated areas for isolating loud machines and grouping quieter machines can prove effective in controlling the exposure. The distance between the source of high levels of noise and the employees must be greater, which can be done by placing them in separate rooms, restructuring walls, noise barriers and partitions from quieter zones.
Managerial Control
The administration can control the excessive amount of noise level by limiting the time a worker is exposed to it. For this, an effective strategy of sound monitoring and reduction would be adjusting shift schedules to reduce the longer duration of exposure an individual is subjected to, which leads to hearing damage and fatigue. Worker rotation is another solution where the function and work areas of employees can be intermittently rotated across floor levels with varying sound intensities and quieter environments.
Inculcating safety culture through noise awareness training is recommended. This includes educating workers about safe work practices, suggested use of noise dampening equipment, and the efficacy of proactive noise control measures against the risks of excessive noise levels. Certain designated quiet zones such as resting places and meeting areas can be established within the manufacturing setup. Such places assist workers to recover from prolonged exposure to high intensity sounds in the workplace, reduce fatigue, stress, and promote effective communication as and when required.
Assessment & Feedback
Feedback from workers through surveys can prove valuable for evaluating the measures applied for noise control apart from direct sound intensity measurement. The workers’ comfort, perception of sound level, and adverse effects faced by them due to exposure can be accurately measured through surveys. It is also useful in highlighting regions where inadequate control measures have been applied, and further improvements are required. Communication on a regular basis is complementary information to objective dosimeter or sound level meter data as it provides in-depth real-world insights into the impact of noise control measures and efforts.
Advantages of Industrial Noise Monitoring
Given below are some well-known advantages of implementing noise control strategies in manufacturing environments.
1. Employee Well-Being: Implementation of such systems reduces workers’ stress and fatigue, and thus leads to higher job satisfaction, workplace morale, lowered worker compensation claims, turnover rates with safer working conditions.
2. Operational Productivity: Noiseless environments can foster accuracy, efficiency, and render focus over operations, thus leading to fewer errors, downtime, effective communications, emergency responses, higher productivity and strengthening of the manufacturing brand.
3. Regulatory Compliance: Noise monitoring standards and safety regulations are met in real-time at all levels to avoid workplace safety violations and fines. Thus, in turn it also promotes public health protection, improves urban planning, regulates industrial operations, and sustains the environment.
4. Cost Efficiency: Absenteeism, workspace accidents, and equipment wear can be controlled over longer durations of implementing these systems.
5. Damage Prevention: Cracks caused by excessive vibrations in bridges, buildings, equipment, and other structures, given their agility and fragility, can be monitored or avoided.
6. Informed Decisions: Through continuous monitoring, project engineers are informed about the impact of activities on the shop floors and legal claims which helps them to plan and adhere to project criteria.
Join Hands with KritiKal for Precise Sound Monitoring
From the above discussion, it is fair to conclude that effective noise control in SMEs and large enterprises is a prerequisite for retaining employees, fostering a safe workplace, maintaining good relations with the authorities, society, and balancing the surrounding environment. This requires comprehensive strategies and integrated approaches, such as various administrative measures, engineering controls, machinery modifications, rotations in worker shifts, sound barriers, PPE, hearing protection, and more as discussed in the blog. A noise pollution monitoring system protects worker health, reduces fatigue, stress, hearing loss, and improves morale and productivity. By combining low-cost solutions such as these tailored to the organization’s operational needs, government support, smart manufacturing solutions, and regular monitoring of sound intensities, long-term safety, efficiency, regulatory compliances, and adaptive revolution of the manufacturing industry can take place.
KritiKal Solutions can develop sophisticated products and sensors for monitoring noise in the environment and manufacturing setup. We seamlessly integrate noise levels data into alert generation software that features detailed summary reports that are swiftly and automatically sent to the concerned employees and management. Notifications for exceeding limits of vibrations, noise, and more are continuously monitored through our AI-powered systems for accurate and reliable indication of compliance with noise level standards. We have been long term partners in the development of various smart Industry 4.0 solutions for various SMBs and manufacturing giants across the globe. Please get in touch with us at sales@kritikalsolutions.com to know more about our products, leverage comprehensive, customized, and turnkey services, and to realize your manufacturing requirements.
Sai Narasimha Darsinala currently works as an Embedded Firmware Engineer at KritiKal Solutions. He is proficiently skilled in C, C++, and Embedded C. He has hands-on experience with STM32 and PIC32 microcontrollers, ESP32, Arduino, and Raspberry Pi platforms, and is proficient in communication protocols such as UART, CAN, SPI, and I2C, etc. With his ability to work efficiently in teams and passion for embedded systems development, he has assisted KritiKal in delivering various projects to major clients.