Composed of acoustics experts with over 25 years of experience in the market, OTOH Sound Monitoring was founded in 2022 with the mission of revolutionizing the sound measurement market by offering a Low-cost, Versatile, Reliable and Friendly service.

We facilitate noise monitoring, helping to manage noise pollution anytime, anywhere, in the palm of your hand.

Reduce financial and operational risks while improving the relationship with the community.

Reduce the financial and operational risks of poor noise management while improving community well-being with our Sound Monitoring.

At OTOH, we are ready to help you solve noise problems with cutting-edge technology and personalized service.

Contact us to request a quote, ask questions or get more information about our sound monitoring services.

Frequently asked questions and answers about continuous sound monitoring

Carolina Monteiro

Leonardo Jacomussi

Marcel Borin

Paola Weitbrecht

Graziela Caruso

Cecilia Jardim

During monitoring with our service, you have complete autonomy in noise management, allowing for quick and proactive decision-making. With access to real-time data, our technology identifies problems before they become serious, ensuring efficient control and prevention.

We assess your needs before sending you a proposal. Our technical team listens to your problem to assess the best way for you to manage your noise, suggesting the number of sensors needed and the best installation locations so you can understand the soundscape of the location.

After contracting, we will come to you to install the sensors. During the monitoring period, monitoring is done remotely, with technical visits for maintenance or uninstallation as necessary.

Autonomy and Proactivity

Personalized Assessment

Installation and Maintenance

Available 24/7 on any browser, our intuitive platform allows you to access and interpret data in real time, making noise management agile and proactive.

Our innovative technology offers continuous noise monitoring, with short and long-term campaigns, customized to your needs.

Easy to install, our sensors use artificial intelligence to identify the sources that generate the most noise, allowing continuous, proactive and remote management.

Cutting-edge technology in sound monitoring

24/7 Platform

Flexible Deadline

Smart Sensors

Here you can stay informed about OTOH, and clarify your main questions.

Knowledge HUB

At 2 p.m. on a Tuesday, a team positions a sound level meter 1.5 m from a hydraulic press. Production is steady, the building doors are closed, and no truck is unloading coils in the yard. The result—82 dB(A)—goes into the report. Three weeks later, a resident in the neighboring complex reports peaks shortly after midnight. Maintenance discovers that a 75 kW exhaust fan operated without its silencer that night. Occupational Safety asks about exposure for the night-shift operators; the Environmental team asks about the level at the boundary wall.

Everyone is talking about "noise," but they are not asking the same question.

This scene captures a common challenge: a spot measurement is a photograph; continuous monitoring helps reveal the film. The photograph may be technically indispensable. The film adds sequence, duration, and context. Neither invalidates the other—and neither reduces noise on its own.

This guide organizes the main regulatory and technical layers for anyone who must manage industrial noise in Brazil without confusing worker exposure, community disturbance, legal obligations, and operational intelligence.

First: occupational noise and community noise are different problems

Occupational noise is the sound exposure a worker receives while performing their duties. The central question is: how much sound does that person accumulate over the workday, considering tasks, movement, breaks, and operating variations? This is why personal dosimetry follows the worker or a similar exposure group.

Environmental or community noise is the sound that reaches an inhabited area or external receiver: a home, school, hospital, or another sensitive location. The question becomes: what is the activity's sound contribution at that place and time, considering residual sound and source characteristics?

Both may originate from the same compressor, boiler, or stamping line, but they serve different purposes and use different measurement positions and criteria. An occupational result does not automatically demonstrate environmental compliance. A reading at the property boundary does not, by itself, represent an operator's noise dose.

For a closer look at the methods and acronyms, see the guide to NR-15, NHO-01, and NBR 10151. To turn data into a management routine, read how to connect the factory floor and the surrounding community.

The regulatory map: which framework answers which question

Brazil does not have a single "noise law" that resolves every industrial scenario. The applicable framework combines Occupational Safety and Health rules, environmental assessment, local legislation, licensing, and professional accountability.

NR-01 structures Gerenciamento de Riscos Ocupacionais (GRO) [Occupational Risk Management]. Its documented instrument is the Programa de Gerenciamento de Riscos (PGR) [Risk Management Program], which includes a risk inventory and action plan. If noise is identified as an occupational hazard, it must be addressed through this process: recognize exposures, assess risks, define preventive measures, track results, and review them when necessary [1].

This shifts the discussion from "we took a measurement" to "how does this data inform a risk decision?" The PGR is not a static file. Changes in process, equipment, layout, working hours, raw materials, or evidence that controls are inadequate may require a new assessment.

NR-09: representative assessment and the action level

NR-09 establishes requirements for assessing occupational exposure to physical, chemical, and biological agents identified in the PGR and for informing its preventive measures [2]. Quantitative assessment, when required, must be representative of exposure. In plain terms, measuring an easy or unusually quiet condition does not describe a normally more variable workday.

Under the wording in force in 2026, while NR-09 has no specific noise appendix, its transitional provisions refer to the criteria and limits in NR-15 and set the action level at half the dose. This benchmark triggers systematic controls before the exposure limit. It does not mean that any isolated reading above a certain number automatically represents a 50% dose; dose combines level and time under the selected criterion.

NR-15: unhealthy working conditions and tolerance limits

NR-15 addresses atividades e operações insalubres [activities and operations considered unhealthy under Brazilian labor law]. Annex 1 covers continuous or intermittent noise; Annex 2 covers impact noise [3]. Although Annex 1 presents a table of levels and durations rather than naming the following parameters, its criterion corresponds to a q=5 dB exchange rate and an 85 dB(A) integration threshold level (NLI, from the Portuguese term), as clarified by Fundacentro [5].

The "q" value indicates how much the level may rise for the permissible duration to be halved. Under the q=5 criterion, a 5 dB increase represents this exchange between level and duration. This is not the same calculation used in NHO-01.

NHO-01: a technical occupational hygiene procedure

Fundacentro's NHO-01 details how to assess occupational noise exposure. It uses q=3 dB and an NLI of 80 dB(A) and addresses noise dose, Nível de Exposição (NE) [exposure level], Nível de Exposição Normalizado (NEN) [normalized exposure level], the action level, and impact-noise criteria [4].

With q=3, every 3 dB increase doubles sound energy and halves the corresponding duration. Fundacentro itself explains that NHO-01 and NR-15 differ significantly and that changing NHO-01 parameters to q=5 undermines the NEN concept [5]. Therefore, results obtained with q=3/NLI 80 and q=5/NLI 85 are not interchangeable. The report must state the criterion and instrument settings.

NR-07: audiometry monitors health; it does not measure the source

NR-07 organizes the Programa de Controle Médico de Saúde Ocupacional (PCMSO) [Occupational Health Medical Control Program]. Its Annex II establishes occupational medical monitoring of hearing for employees exposed above the action levels stated in the PGR, regardless of hearing-protector use [6].

For these employees, audiometric testing must occur upon hiring, annually, and upon termination. At termination, an examination performed up to 120 days before the employment ends may be accepted, and the responsible physician may shorten the interval when justified.

Audiometry and environmental assessment play complementary roles. The former monitors the worker's hearing; the latter characterizes exposure or the environment. An audiogram does not identify which machine generated a peak. A sensor does not diagnose hearing loss.

For environmental noise, CONAMA Resolution No. 01/1990 establishes criteria for sound emissions from activities and refers to the technical standard for assessment in inhabited areas [7]. The current reference for fixed sources is ABNT NBR 10151:2019, corrected version 2020, according to guidance from CETESB, the São Paulo State environmental agency [8].

NBR 10151 provides three routes: a simplified method, only for continuous or intermittent sounds without tonal or impulsive contributions; a detailed method, for overall and spectral characterization, including tonal or impulsive sounds; and a long-term monitoring method, recommended for urban planning and 24-hour monitoring [8]. The latter uses descriptors representative of the relevant periods, such as Ld and Ln; it does not apply to tonal or impulsive sounds, which require the detailed method.

The standard requires a Class 1 or Class 2 integrating sound level meter compliant with IEC 61672, a compatible calibrator compliant with IEC 60942, traceable laboratory calibration, and field adjustments/checks. In ordinary measurement series, adjustment with the calibrator occurs before the series and the verification reading at the end; full-period or long-term monitoring has its own requirements for checks, weather conditions, and data processing [8]. Calling a data series "continuous" is therefore not enough to qualify it as the standard's long-term monitoring method.

The national framework does not settle every issue. Brazilian states and municipalities may have their own land-use rules, time periods, limits, and procedures. Environmental permits, agreements, and permit conditions may also prescribe specific points, frequencies, and monitoring formats. The right question is not merely "what limit is in NBR 10151?" but "which set of rules applies to this source, at this address, at this time, and under this permit?"

A short glossary that prevents major confusion

Noise dose is a percentage combining the intensity and duration of occupational exposure. Think of it as a daily budget: different periods consume fractions of that budget, and those fractions are added to estimate the dose. The result depends on the configured criterion.

NE, or Nível de Exposição [exposure level], represents average occupational exposure for the assessed period under NHO-01. NEN, or Nível de Exposição Normalizado [normalized exposure level], converts NE to a standard eight-hour workday, allowing consistent comparison with the reference criterion [5].

LAeq,T is the A-weighted equivalent continuous sound pressure level over interval T. Put simply, it condenses the varying sound energy over that period into one equivalent level. The "T" matters: a 15-minute LAeq does not automatically describe eight hours or an entire night.

LAFmax is the highest sound level recorded using A-weighting and Fast time weighting. It helps show maxima but, on its own, says nothing about duration, repetition, cause, or compliance.

Ld and Ln represent A-weighted equivalent continuous sound levels for daytime and nighttime periods, respectively. In NBR 10151, they are descriptors used by the long-term monitoring method; they are not synonyms for any freely selected average shown on a dashboard [8].

Spectrum divides sound into frequency bands. It is like replacing an invoice total with an itemized list: two events may have similar LAeq values but different spectral signatures. This information can support investigations of fans, saws, alarms, or impacts. Even so, without context and validation, similarity does not prove causation.

"We measure once a year": is that enough?

There is no universal annual frequency for every noise measurement.

"Annual" appears in the applicable audiometric monitoring under Annex II of NR-07, but it must not be copied as a generic rule for any occupational or environmental assessment. Reassessment depends on the PGR, data representativeness, process changes, control effectiveness, incidents, and local requirements or permit conditions.

A well-planned periodic campaign can answer a formal question with traceability. Its limitation is the interval between campaigns. If the factory alternates products, shifts, production recipes, speeds, or maintenance conditions, one visit may not capture every relevant condition.

This is where the photograph–film distinction helps:

the photograph formalizes a defined sample, with a specified method, professional, instrument, and purpose;

the film tracks trends, recurrence, and events between those samples;

the technical decision uses each item of evidence within its limitations.

What continuous monitoring can—and cannot—do

A fixed sensor can track time series, flag pattern changes, issue alerts, compare periods, and preserve history, provided its performance and installation suit the purpose. When it measures sufficient spectral data and a validated operating-source catalog exists, it can support probabilistic source classification—for example, distinguishing the spectral pattern of an exhaust fan from the noise of trucks unloading in the yard. OTOH's embedded AI performs this classification in real time, directly on the sensor, cross-referencing spectral signatures and temporal patterns to label each event before transmitting the indicators to the cloud.

"Probabilistic" remains the key word. The AI was not present as a witness, does not control every competing source, and does not prove a causal link. The hypothesis generated by the model must be checked against production records, inspections, maintenance, and, where necessary, an assessment by a competent professional.

There are also metrological and spatial limitations. A fixed point represents the acoustic conditions at that specific location. Personal exposure varies with the worker's position and task—an operator who moves between the press and the warehouse accumulates a different dose from the colleague stationed in the control booth. Therefore, a fixed sensor does not replace personal dosimetry, a technical assessment, or an expert examination.

Long monitoring periods must also contend with rain, wind, obstructions, power or communication failures, instrumental drift, and data volume. The program must address quality, availability, and traceability—not merely collection.

On privacy, the sensor's architecture defines the risk perimeter. OTOH sensors process acoustic data locally, on the device itself, and transmit only indicators—levels, spectra, and source classifications—to the cloud. No raw audio is recorded, transmitted, or stored at any stage [9]. This approach eliminates the most sensitive vector (capturing conversations and identifiable sounds), but it does not exempt the project from a full analysis under Brazil's General Data Protection Law, the Lei Geral de Proteção de Dados Pessoais (LGPD): purpose, legal basis, necessity, transparency, access, retention, and security remain mandatory. Even without audio, acoustic indicators, metadata, and correlations may enable inferences about activities and individuals. Data governance is part of the design, not an add-on.

A data-rich timeline may improve diagnosis, but monitoring does not reduce noise on its own. Reduction comes from actions guided by the hierarchy of controls:

eliminate or substitute the source where feasible;

apply engineering controls—enclosures, silencers, vibration isolation, maintenance, and redesign;

adopt administrative controls and organize times, routes, and tasks;

use appropriate hearing protection where indicated, without treating it as an automatic substitute for collective measures.

The auditory effects of occupational noise exposure are supported by strong evidence, including noise-induced hearing loss and communication difficulties [10]. For cardiovascular outcomes associated with environmental noise, the literature and the World Health Organization (WHO) describe associations and plausible mechanisms, but effect size, individual causation, and transferability between populations remain uncertain [11]. Responsible writing does not turn an epidemiological association into a diagnosis for an individual or community.

A practical roadmap for integrating the photograph and the film

1. Separate the questions. List occupational exposure, environmental impact, operational investigation, and permit obligations on separate lines.

2. Map sources and receivers. Include machines, routes, shifts, workers, the property boundary, and sensitive neighbors.

3. Confirm the applicable framework. Review the NRs, PGR/PCMSO, state and municipal legislation, the permit, and its conditions. Record which criterion each instrument uses.

4. Plan formal assessments. Define representative groups, tasks, points, periods, calibration, the responsible professional, and the appropriate method.

5. Use time-based tracking where a real gap exists. History and alerts can help select inspection times and the events to correlate.

6. Investigate, control, and verify. Turn the signal into a hypothesis, the hypothesis into an engineering action, and the action into an effectiveness check.

7. Reassess based on triggers, not an automatic calendar. Changes and new evidence should feed back into GRO, the PGR, and environmental management.

OTOH sensors address the time-based tracking, alerts, history, and real-time source-classification stages. This does not guarantee regulatory compliance or make every facility a suitable case for continuous monitoring. The design must begin with the technical problem, not with the availability of technology.

Is continuous monitoring mandatory in every industrial facility?

No. The obligation depends on the applicable standards, local legislation, permits, and permit conditions. It may be a voluntary management tool or a specific requirement, but there is no universal rule covering every facility.

Does a sensor inside the building replace the worker's dosimeter?

No. A dosimeter tracks personal exposure across tasks. A fixed sensor represents the location where it is installed.

Does an LAeq below a certain value guarantee compliance?

Not in isolation. You must know the purpose, period, location, method, residual sound, specific sound, tonal or impulsive characteristics, criterion, and applicable rules.

Do NR-15 and NHO-01 produce the same result?

Not necessarily. NR-15 corresponds to q=5/NLI 85; NHO-01 uses q=3/NLI 80. The results are not interchangeable.

Can artificial intelligence identify the source with certainty?

No. It classifies patterns probabilistically—indicating, for example, that an event has an 87% similarity to the spectral profile of a compressor. Confirming the cause requires cross-referencing with operational records and, when necessary, on-site inspection.

No. Data supports decisions; control requires engineering measures, organization, maintenance, protection, and verification.

Understand the distinction between occupational and community noise, the role of Brazilian NRs and NBR 10151, and when continuous monitoring complements formal measurements.

Industrial noise: legislation, measurements, and continuous monitoring in Brazil

Taking care of workplace health and safety is fundamental for any company that aims not only to comply with laws but also to create a productive and healthy environment for its employees. In Brazil, Norma Regulamentadora 1 (NR1) sets out the general rules for managing workplace risks, serving as the foundation for all other standards. In this context, noise in the work environment often appears as a subtle risk, but one that can have a major impact on employee health and the legal compliance of companies.

This article covers NR1, the importance of managing noise, what can happen when noise is not managed properly, and how OTOH can help overcome these challenges—turning compliance into a competitive advantage for your business.

The May 2025 version of NR1 focuses on the Programa de Gerenciamento de Riscos (PGR — Risk Management Program). The PGR is a continuous process that involves identifying, assessing, and controlling hazards and risks present in the workplace. It requires companies to:

Identify hazards by recognizing what can cause health problems or accidents.

Assess risks by analyzing the likelihood of harm and the potential severity of the consequences.

Implement control measures and create actions to eliminate, reduce, or control risks.

Monitor and review by tracking control measures and evaluating their effectiveness to revise the PGR periodically or when there are changes at work.

Noise, being a physical agent, is one of the risks that must be included in the PGR. NR1 does not set noise limits but refers to other standards such as NR15 (Insalubrious Activities and Operations) and NR17 (Ergonomics), which establish exposure limits and necessary control measures. Even so, NR1 clearly requires an active and organized approach to manage all risks, including noise.

The Impact of Noise on Health and NR1 Compliance

Excessive workplace noise is a serious health and safety issue. Its effects go far beyond hearing loss—which is already a serious and irreversible problem. Constant exposure to high levels of noise can cause numerous health issues, as demonstrated by studies and reports from the European Environment Agency (EEA) [1]:

Sleep Difficulties: Trouble falling asleep, disrupted or unrefreshing sleep, leading to fatigue, irritability, and impaired thinking.

Stress and Mental Health: Increased stress, anxiety, depression, and irritability, directly impacting employee well-being and work capacity.

Difficulty Concentrating: Impaired attention, memory, and learning ability, especially in children exposed to transport noise.

Heart Problems: Constant noise can raise blood pressure, increasing the risk of heart disease and stroke.

Other Effects: It can contribute to the development of type 2 diabetes, obesity, and even memory problems in cases of prolonged and intense exposure.

The Impact of Noise on Business Operations

In addition to the direct impact on workers’ health, poor noise management leads to serious consequences for NR1 compliance and for the company itself. These consequences go beyond health issues and can represent a significant financial burden:

If noise is not properly identified, assessed, and controlled in the PGR, the company may face hefty fines from agencies such as the Ministério do Trabalho e Emprego. Non-compliance can bring severe sanctions and harm to the company’s reputation.

Employees who develop health problems due to noise (such as noise-induced hearing loss—PAIR) can file lawsuits. These actions may result in considerable indemnities and pensions secured under Tema 555, which can amount to up to 75% of the company’s payroll value [2].

Distraction caused by noise can lead to mistakes and accidents at work, putting everyone’s safety at risk. Noisy environments affect attention and communication—crucial factors to prevent incidents. While it’s difficult to quantify the cost of accidents specifically caused by noise-related distraction, the overall increase in accidents and productivity loss is a direct consequence of noisy environments, generating significant costs for businesses.

Noisy workplaces hinder concentration, communication, and overall employee well-being, lowering productivity and work quality. Globally, noise pollution costs the economy about US$ 5 trillion a year in lost productivity [3]. In the US alone, productivity losses due to environmental noise already exceed US$ 81 billion [4].

Companies that neglect their workers’ health and safety may suffer reputational damage, making it harder to recruit and retain top talent. This affects both the employer brand and public perception of the company.

OTOH’s Continuous Sound Monitoring: The Solution for Managing Noise and Complying with NR1

Given the challenges posed by workplace noise and NR1 requirements, OTOH offers a modern and comprehensive solution: continuous sound monitoring. Our services are designed to transform the way companies manage noise, ensuring compliance, protecting employees’ health, and enhancing operations.

AI-Powered Smart Sensors: Our sensors are easy to install and use artificial intelligence to identify noise sources, enabling active and remote management. This means you don’t just measure noise, you know where it comes from and what causes it.

Real-Time Data, 24/7: With a user-friendly platform available on any browser, you access real-time data. This clear vision enables quick, effective decisions, identifying problems before they get serious.

Personalized Assessment: OTOH does not offer one-size-fits-all solutions. Our team of acoustics specialists assesses your specific needs, suggesting the optimal number of sensors and the best installation points, so you get a complete understanding of sound in your environment.

Reduced Risks and Costs: By identifying and managing noise efficiently, your company significantly reduces the risks of fines, lawsuits, and accidents. Moreover, optimized management can lead to long-term cost savings.

Greater Well-Being and Productivity: A workplace with controlled noise directly contributes to employee well-being, resulting in greater focus, clear communication, and naturally, increased productivity.

NR1 is clear: managing workplace risks is an ongoing and comprehensive responsibility. Noise, with its subtle yet harmful effects, demands special attention. Failing to manage it is not just a health risk for workers but also a legal and financial issue for companies.

With OTOH’s continuous sound monitoring, your company not only meets NR1 requirements but goes beyond, creating a safer, healthier, and more productive work environment. Invest in smart noise management and turn a challenge into a competitive edge for your business.

NR1 is the Regulatory Standard that sets out general guidelines for managing occupational risks in Brazil and serves as the foundation for all other NRs.

Why is noise an important risk under NR1?

Noise is a physical agent that can cause serious health problems for workers (such as hearing loss, stress, and cardiovascular issues) and create legal and financial consequences for companies that fail to manage it properly.

How can OTOH help my company comply with NR1 regarding noise?

OTHO offers continuous sound monitoring using smart sensors and artificial intelligence that allow you to identify noise sources, access real-time data, and implement effective control measures—ensuring compliance and a safer work environment.

What are the benefits of OTOH’s continuous sound monitoring?

Benefits include risk and cost reduction (fines, lawsuits), improved employee well-being and productivity, personalized assessment of company needs, and real-time data access for quick decision making.

[1] European Environment Agency. Environmental noise in Europe 2025. Available at: https://www.eea.europa.eu/en/analysis/publications/environmental-noise-in-europe-2025. Accessed: Jul. 7, 2025.

[2] Tema 555/stf. Available at: https://jurisprudencia.stf.jus.br/pages/search?base=acordaos&sinonimo=true&plural=true&page=1&pageSize=10&sort=_score&sortBy=desc&isAdvanced=true&origem=AP&classeNumeroIncidente=ARE%20664335. Accessed: Jul. 7, 2025.

[3] Silencio Network. The Real Cost of Noise: How it Affects Us All. Available at: https://silencionetwork.medium.com/the-real-cost-of-noise-how-it-affects-us-all-c8b5046c9a80. Accessed: Jul. 7, 2025.

[4] PMC. Valuing Quiet: An economic assessment of US environmental noise .... Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC4819987/. Accessed: Jul. 7, 2025.

[5] Governo Federal. Norma Regulamentadora No. 1 (NR-1). Available at: https://www.gov.br/trabalho-e-emprego/pt-br/acesso-a-informacao/participacao-social/conselhos-e-orgaos-colegiados/comissao-tripartite-partitaria-permanente/normas-regulamentadora/normas-regulamentadoras-vigentes/nr-1. Accessed: Jul. 7, 2025.

Discover how noise management is essential for compliance with NR1, occupational health, risk reduction, and operational costs. And how continuous monitoring can be the best tool for effective noise management.

NR1 and Workplace Noise: Why Taking Care of Sound is Essential for Your Business and Everyone’s Health

How real-time noise monitoring transforms construction management and strengthens companies’ social and environmental responsibility.

For companies operating in urban areas and sectors such as construction, noise control has shifted from a secondary concern to a top priority. Effective noise monitoring not only contributes to the well-being of surrounding communities but also protects company operations from legal risks, complaints, and potential shutdowns. In this context, continuous monitoring emerges as a modern and indispensable solution, enabling active and preventive management of noise levels. By combining innovation and accessibility, OTOH offers a platform that simplifies sound monitoring and delivers tangible results in efficiency and environmental compliance.

The Challenge of Noise Control in Operational Environments

Constant exposure to noise is a well-documented problem that affects millions of people across Europe and has impacts that go beyond discomfort. Chronic noise, especially that originating from urban roads and industrial activities, is linked to a number of health issues like cardiovascular diseases, sleep disorders, and increased stress, according to data from the World Health Organization (WHO). In the construction sector, these issues are even more prevalent due to the use of heavy machinery and the proximity of projects to residential and commercial areas​​.

Beyond community impacts, intense noise poses a direct risk to the health of construction workers. Prolonged exposure can cause hearing loss, increased blood pressure, and chronic stress, compromising workers’ well-being and safety. For Health, Safety, and Environment professionals (HSE), the challenge of monitoring and managing these noise levels is fundamental, as inadequate control can lead to unhealthy work conditions, higher rates of leave, and physical strain.

For professionals overseeing large-scale projects and infrastructure works—such as engineers, quality managers, and HSE specialists—the absence of accurate noise control can result in costly corrective actions, community conflicts, and harm to corporate reputation. In fact, studies show that without proper monitoring, regulatory compliance and adherence to noise limits are compromised, increasing operational and legal risks​.

Continuous Monitoring: How Does It Work in Practice?

Given these challenges, continuous monitoring stands out as a key tool for companies seeking to remain aligned with environmental and health regulations. Instead of isolated assessments, continuous monitoring uses strategically placed sensors that capture real-time noise data, generating ongoing insights for proactive management.

The OTOH platform incorporates an advanced Artificial Intelligence tool that automatically identifies noise sources exceeding set limits. With these valuable insights, managers can visualize critical noise areas and times, allowing for quick, precise operational adjustments. The data is presented in user-friendly visual reports and simplified graphs, making it easy for the entire team to understand regardless of technical background.

This technology reduces the need for frequent manual inspections, optimizing teams’ time and enabling proactive, targeted noise management in an efficient and regulation-compliant manner.

How Can Continuous Monitoring Benefit You?

OTOH’s continuous monitoring technology was designed to deliver tailored benefits for each project area, from engineers and quality managers to legal professionals.

For site engineers, 24/7 monitoring provides a detailed view of noise impact throughout different construction phases, enabling operational adjustments that minimize noise and maximize efficiency. For example, by detecting spikes at critical moments, the team can adjust schedules or implement acoustic barriers, keeping the project within noise limits and avoiding unexpected stoppages.

For quality and HSE managers, the platform helps maintain a level of control that not only meets regulatory standards but also ensures a safe workplace in line with Health, Safety, and Environmental best practices. OTOH’s precise data supports ongoing monitoring of noise limit compliance, minimizing occupational health risks, preserving the company’s image, and showcasing a commitment to sustainability and community well-being.

For legal professionals, continuous monitoring represents an essential database for litigation or audit scenarios. In disputes, OTOH’s reports serve as evidence of the company’s compliance with noise regulations, reducing the risk of penalties and strengthening the defense’s case. These robust, organized data sets are critical for legal teams in cases related to environmental and community impact​​.

Real Impact Example: When Continuous Monitoring Makes the Difference

A practical example of the impact of continuous monitoring occurred at an urban construction site, where a building company faced a lawsuit from the Public Prosecutor’s Office due to neighbor complaints about noise. The project was halted, threatening its continuation. By implementing OTOH’s Real-Time Sound Monitoring tools, the construction company began collecting detailed data on noise levels, enabling precise analysis of critical sources and times.

Armed with these insights, corrective actions were taken, such as adjusting the operation schedule and strategically relocating pumps and equipment within the site, significantly reducing the noise impact. The reports generated by OTOH demonstrated the company’s commitment to noise mitigation, which helped resume activities and lift the shutdown. Long-term monitoring was maintained until the end of the project, preventing new conflicts and strengthening relationships with both the community and authorities. This real-life case shows how OTOH technology turns challenges into practical solutions, protecting company reputation and ensuring project continuity.

Continuous Monitoring and Social-Environmental Responsibility

OTHOH does more than provide a technical solution—it is dedicated to socially and environmentally responsible practices that foster healthier environments for all. Continuous monitoring technology directly supports sustainability by enabling strict noise control, respecting local wildlife, vegetation, and the well-being of nearby communities. By complying with health and environmental regulations, companies using OTOH show a clear commitment to sustainability and to the Sustainable Development Goals (SDGs), contributing to community health and quality of life​​​.

How Can Your Company Transform Noise Management and Avoid Project Shutdowns?

Lead the way in efficient noise management and avoid legal and operational risks. With OTOH’s continuous monitoring, you bring innovation to the core of your operations, turning data into strategic decisions while preventing conflicts with communities and regulators.

Interested in seeing how our platform can transform your team’s noise management? Get in touch and request a demo to discover OTOH’s benefits and features firsthand.

Phone: (11) 2780-0323
Email: contato@otoh.com.br

This article demonstrates how real-time noise monitoring transforms construction management and strengthens companies’ social and environmental responsibility. We discuss the challenge of noise control in operational environments and how continuous monitoring can benefit your business in practice. With examples of how continuous monitoring makes a difference and has real impacts on companies, and how it demonstrates social-environmental responsibility, plus an explanation of how your company can transform noise management and avoid project shutdowns.

Continuous Monitoring: Reducing Risks and Enhancing Operational Efficiency

If you work in the construction industry in the city of São Paulo, you’ve certainly heard about Decree No. 60.581, which regulates construction noise emissions in the city. You might even be familiar with the document and have memorized the established noise limits. Even so, you probably still have many questions about what needs to be done to comply with the noise decree.

In this article, we aim to explain the rules of Decree No. 60.581 in a straightforward way and introduce a noise monitoring system that can help you take action in real time, ensuring that the noise produced at your site stays within the decree’s established limits.

Decree No. 60.581 – regulates construction noise control

Decree No. 60.581, published on September 27, 2021, “regulates noise control during the execution of construction works in the Municipality of São Paulo.” This means that every construction project subject to an Execution Permit in the city of São Paulo must comply with the noise limits set by this decree, except for certain situations we’ll present next.

If the provisions of the decree are not followed, violators are subject to penalties based on Article 146 of the Law No. 16.402 – Land Subdivision, Use and Occupancy Law, as outlined in item 12, Table 5, annexed to the LPUOS.

Noise emission limits set by Decree No. 60.581

It’s impossible to carry out a construction project without increasing the typical noise levels in the area. That’s why the decree states that “the worsening” of noise pollution will be considered normal due to the increase in noise-emitting agents (various types of machines and noisy construction activities).

Even though it’s understood that discomfort from noise is inevitable during construction, it’s essential to have regulations to ensure noise levels don’t exceed acceptable limits, especially during rest periods.

This is precisely the purpose of Decree No. 60.581, which sets noise emission limits based on days of the week and times. These limits are shown in the following table.

Cases not subject to the noise decree limits

Not all construction projects are required to comply with the noise emission limits set by Decree 60.581: specifically, public works and emergency works.

Other private civil constructions are also exempt from the limits in the following situations: loading and unloading, earthmoving phase, foundation, demolition, and structure, as long as the days and hours specified in the decree are respected.

If there is any violation concerning these times and days, which condition these two exceptions, the penalties described in Article 5 must be applied.

By the end of this article, you’ll be ready to take the necessary actions to avoid any trouble regarding your construction’s noise emissions and with noncompliance with the decree.

In any case, it’s important to clarify the penalties violators might face if the site’s noise exceeds the established limits.

To start, the decree considers violators to be “the property owner or holder, and, when applicable, the technical manager of the project.”

The penalties, as set out in Article 5 of the decree, become more severe with each recurrence:

1st notice: in addition to a fine (the amount set in the Table 5, annex of LPUOS), an official notice will be issued to stop the irregularity.

2nd notice: if the violation recurs, the fine will be double the previous amount and another notice will demand the issue be resolved.

3rd notice: the third notice results in a fine three times greater than the first and a shutdown of the project.

Recurrence means every infraction after the first for the same work, within a one-year interval.

Measurements to confirm compliance, as well as the issuance of citations, are carried out by PSIU – Technical Division for Urban Silence Inspection.

In cases where the violation persists, according to Article 7 of the decree, PSIU can take more drastic measures, referring the case to the Police Department, CREA or CAU, and the Department of Defense of the Environment and Heritage of the General Attorney’s Office of the Municipality (DEMAP).

Decree No. 60.581, published on September 27, 2021, “regulates noise control during the execution of construction works in the Municipality of São Paulo.” This means that every construction project subject to an Execution Permit in the city of São Paulo must comply with the noise limits set by this decree, except for certain situations we’ll present next.
OTOH is a smart, low-cost sound monitoring system that lets you check noise levels in real time. With strategically placed sensors on your site, you can analyze noise data through a user-friendly platform, using a computer or mobile device.

Industrial noise: legislation, measurements, and continuous monitoring in Brazil

Latest articles

NR1 and Workplace Noise: Why Taking Care of Sound...

Continuous Monitoring: Reducing Risks and...

São Paulo Construction Noise Decree: What You...

Intelligent Sound Monitoring: Noise Management in...

Sound monitoring for urban noise management and...