How can you correctly measure noise?

You may be engaged in noise measurements in a workshop, measuring with all objects running simultaneously. If you stay there, you will get the data for all objects and the overall sound pressure level in the room. In many cases, background noise may drown out the particular machine noise during measurement. How do you eliminate the background noise and correct the influence?

What you need to do is to measure the sound pressure level with the objects running, and then switch off the objects and measure the background level, calculate the difference between these amounts, locate this on the horizontal axis on the graph below, go up until you intersect the graph, and then go to the vertical axis to the left. Subtract this value from the overall level, and you get the machine sound pressure level. Alternatively, you can utilise the equation to get the result.

Background noise matters to our noise measurement. Before measurement, we have to observe the environment to measure the noise level and identify the ideal location of the monitoring station. There are numbers of points we need to pay attention to when observing the environment. How many noise sources can you find in the environment? What characteristics do the noise sources have? Which location at the site can we pinpoint most of the noise sources? At the site, which directions do the noise sources come from? How far apart are the noise sources? Are there any walls/structures that may cause reflection?

Besides background noise, external factors such as the angle of the sound level meter are placed, and the weather impacts the monitoring. Do we cover most of the noise sources? Is the station close to the noise sources? Is the area encountering human activities? Do we have a good wifi signal and a stable electricity supply? Last but not least, is it safe to access?

After identifying the monitoring location, let us find out what instrument we need for noise measurement.

By: ANewR Consulting Limited, a digital environmental consultant headquartered in Hong Kong since 2008. Our expertise has grown into the context of air and water qualities, noise, green building, waste management, and remediation. With extensive know-how in environmental planning and assessment, feasibility study and policy review, ecological design, monitoring, and audit (EM&A), ANewR has matured to be a leading management consultancy. Standing in the digital transformation reign, ANewR has participated in various environmental digital projects – interactive 3D visualisation, immersive automation virtual environment, Virtual reality, automation system, and monitoring platforms.
(Website: https://anewr.com, LinkedIn: ANewR Consulting Group, Twitter: ANewR – Everyday Newer,
YouTube: https://www.youtube.com/channel/UCnpvmxnR9hbNxytSfBdfV8Q/videos)

The concept of noise

Put yourself into the shoes of a sleepless victim who endure mosquitos emitting a whining sound at night. Certainly, mosquitos sound would not make you lose hearing, but you can say it is noise because of the headache, hearing high-pitched noises, exhaustion, dizziness, and nausea mosquitos cause you. Noise is an unwanted sound connected with the feeling of annoyance.

What is sound? Sound is the vibration transformation into a sound wave through a medium of gaseous, liquid, or solid elastic. The sound wave variation determines whether humans can hear about the sound. Human ears can detect variations at least 20 times a second, but not more frequent than 20000 times a second (20Hz-20kHz). And, this is Hertz.

What is a decibel? dB is a ratio between received and transmitted signal strength on a log scale. 1dB is the slightest variation that human ears can detect. 3dB differences are equivalent to the double of the sound level. The sound level humans receive comprises the sound reflected from the wall and the amount of sound being transmitted into adjacent rooms.

Human ears would not receive the complete sound level emitting from the objects. A certain level would be lost in transmission. Sound power level is the acoustic energy emitted from the source. Another concept is Sound pressure level, which measures what humans hear—the sound pressure level results from the sound energy ejected from the source transmitting to a received location. Sound power is the cause, and sound pressure is the effect.

What happens if we have more than one noise source in the room? Is the result the sum of the individual sound pressures? No, it is not the sum of the particular sound pressures.

What you should do is measure the sound pressure level of each object and calculate the difference. Look at the graph below, find the dB point on the horizontal axis, and find the value on the vertical axis according to the intersection. Add the value onto the most vociferous object. Another method is to calculate the total sound power with an equation.

Now, you have an idea what sound and noise are about. How do we practically and scientifically study noise in our environment?

By: ANewR Consulting Limited, a digital environmental consultant headquartered in Hong Kong since 2008. Our expertise has grown into the context of air and water qualities, noise, green building, waste management, and remediation. With extensive know-how in environmental planning and assessment, feasibility study and policy review, ecological design, monitoring, and audit (EM&A), ANewR has matured to be a leading management consultancy. Standing in the digital transformation reign, ANewR has participated in various environmental digital projects – interactive 3D visualisation, immersive automation virtual environment, Virtual reality, automation system, and monitoring platforms.
(Website: https://anewr.com, LinkedIn: ANewR Consulting Group, Twitter: ANewR – Everyday Newer,
YouTube: https://www.youtube.com/channel/UCnpvmxnR9hbNxytSfBdfV8Q/videos)

When inevitable, how do we do to tackle the noise issue affecting us?

Years ago, ANewR had received a call: “We know we are noisy, it is inevitable. We still want to reduce the noise impact, but we do not know who is the most severe noise generator. We are puzzled.”

Photo above: How would you feel you live nearby? What should the authority do for the neighbourhood?

ANewR told the client: “Noise monitoring is our strength. We have everything here to support. Let us help you.”

Let’s look back: Over the past few years, ANewR has set up the 24-hour noise monitoring system and stations. We have been in charge of the noise monitoring operation and management.

The monitoring approach adopted was scientific; it validated all the reporting and the recommendation to identify the noise impact on our client’s surrounding areas.

Another merit given to the approach was that applying systematic monitoring already ensured compliance with international standards.

Our noise monitoring management process is based on flexibility, and it works. An improved IT infrastructure is supposed to make a quick response to the incident.

In case of the connection failure, the system automatically reconnected to the fixed aviation noise monitoring station and generally operated after a few hours, or resumed regular operation after ANewR reaching to restart the sound level meter short period.

Why do our clients stick with us? Because they can trust in our work. That’s why ANewR has been endeavoring for quality service and IT measure development.

ANewR encourages our clients and staff to find the potential for improvements and innovations.

ANewR is happy about our trustworthy cooperation during the past few years – and the new collaboration will come. Let’s tackle the difficulties together!

Video – When inevitable, how do we do to tackle the noise issue affecting us?: https://www.youtube.com/watch?v=oJxUtcEqIH8&t=2s

By: ANewR Consulting Limited, a digital environmental consultant headquartered in Hong Kong since 2008. Our expertise has grown into the context of air and water qualities, noise, green building, waste management, and remediation. With extensive know-how in environmental planning and assessment, feasibility study and policy review, ecological design, monitoring, and audit (EM&A), ANewR has matured to be a leading management consultancy. Standing in the digital transformation reign, ANewR has participated in various environmental digital projects – interactive 3D visualisation, immersive automation virtual environment, Virtual reality, automation system, and monitoring platforms.
(Website: https://anewr.com, LinkedIn: ANewR Consulting Group, Twitter: ANewR – Everyday Newer,
YouTube: https://www.youtube.com/channel/UCnpvmxnR9hbNxytSfBdfV8Q/videos)

Let tech master the task that is harsh for human

Photos below: Andante noise monitoring system

Andante, a relatively slow tune, is omnidirectional and reverberant. It is difficult to identify the sound source. When it occurs to a workplace, how could we ascertain the sound origin to settle the controversies?

ANewR has the answer – the Andante noise monitoring system comprising stations and platforms.

We are impressed that technology masters a task that is harsh for humans. In a construction site, lots of various equipment and people are operating nearby. When several sub-contractors work for one project, the job to identify the noise-control performance can never be straightforward. ANewR’s noise monitoring station can distinguish three-sixty noise directions – up or down, left or right. Incredibly, the noise compass equips with microphones assuring complete 3D sound occurrence detection. Directional data is exponentially mitigated in time to present a high accuracy indication. The project staff prepares to set the noise compass’s quality pointer to avoid false detection.

Further supported by the CCTV station, the construction activities are under close surveillance. Users can control all CCTV by a single button. CCTV with zooming power makes sure the inspectors witness all construction activities. The monitoring staff effortlessly investigates the dominant noise associated with the construction activities.

To effectively combat environmental negligence, random inspection and control are hardly adequate. Target enforcement action and strategy are placed to surveillance the risk. The risk-based approach uses a monitoring station and webcam system to surveil, and a web-based monitoring platform to release surveillance information. Andante is a sophisticated automatic noise monitoring system operating daily 24-hr continuously to supervise the construction noise monitoring works. It provides all noise monitoring, including measurement data, construction site videos and photos, and data analysis. The system also presents weekly and monthly monitoring data summaries to reflect the performance of the construction activity.

ANewR’s Andante system introduces a step-change in accepted automation methods for environmental monitoring of rail projects. Employed by the Mass Transit Railway (MTR) of Hong Kong, Andante was already successfully used when constructing the South Island Line (SIL) of MTR Corporation. In 2012, the annual Hong Kong ICT Awards awarded MTR the Certificate of Merit in the Best Green ICT Award category to adopt Andante under the monitoring scheme. With anticipated growing use on sites, we encourage its enactment in all infrastructure projects. 

Video – How can you find the noise, not with your ears, but with a scientific method?: https://www.youtube.com/watch?v=oiEHQhrxCBs

By: ANewR Consulting Limited, a digital environmental consultant headquartered in Hong Kong since 2008. Our expertise has grown into the context of air and water qualities, noise, green building, waste management, and remediation. With extensive know-how in environmental planning and assessment, feasibility study and policy review, ecological design, monitoring, and audit (EM&A), ANewR has matured to be a leading management consultancy. Standing in the digital transformation reign, ANewR has participated in various environmental digital projects – interactive 3D visualisation, immersive automation virtual environment, Virtual reality, automation system, and monitoring platforms.
(Website: https://anewr.com, LinkedIn: ANewR Consulting Group, Twitter: ANewR – Everyday Newer,
YouTube: https://www.youtube.com/channel/UCnpvmxnR9hbNxytSfBdfV8Q/videos)

We know that noise is bad for health

Noise can cause elevated heart rate and blood pressure. Noise can alter our immunity system too. It is common for us to experience sleep disturbance with significant problems. To the extreme, we would lose our hearings to a substantial noise level.

Why can’t we have a quiet place to live? Beyond a vast population on limited land, the original site for residential redevelopment already subjects to a high noise environment.

It is challenging to plan and coordinate the long-term housing strategy. In Hong Kong, housing development’s available sites are closed to the heavily trafficked roads and railways. In recent years, you should find individual housings are built around busy streets due to the land scarcity, which in turn, causing us to look for alternative potential redevelopment sites. Redevelopment – the action or process of developing something again or differently – may make use of another land type to fulfill the housing strategy. If, for example, the site formerly was a factory site, it is likely the area enduring heavy vehicle traffic. We love convenience, but housing developed in the present urban area will be unavoidably within the dense traffic area.

Photo above: Why we fail to have a quiet place to live, provided by Maurice Yeung, the charter member of East and South-East Asia Regional Chapter of Acoustical Society of America

Environmental professionals have known many noise mitigation measures – a setback, single aspect design, fins, etc. Still, about nine hundred thousand people in Hong Kong are enduring the inevitable traffic noise. Methods are discovered to protect the residents from traffic noise above 70dB(A) L10(1 hour). Innovative noise mitigation measures are much needed to be explored and developed to reduce the percentage of the population exposed to traffic noise. The percentage of population exposed to traffic noise is a useful comparable benchmark to appraise how well the cities are doing for noise mitigation.

What are the innovative mitigation measures? The creative standards require collaboration and partnership to develop sustainably.

Innovative noise mitigation design (INMD)
The research and implementation of the acoustic window are one of the prime examples of INMD. The acoustic window is a window type yielding a magical solution for a dilemma situation. In the past – and even now, it is still a common issue; an open window drawing the airflow also brings the house with noise. The acoustic window principle is “By arranging two glass panels parallel to each other with openings at alternative sides; traffic noise can be screened off while allowing natural ventilation simultaneously,” defined by the Environmental Protection Department. Acoustic windows have been installed in some recent public housing. The practicability of mounting the acoustic window in the existing housing and mitigating rail noise is under study.

Video 0 Interviewing noise control pioneer in Hong Kong featuring K K Iu : https://www.youtube.com/watch?v=I6axMP-qP3g&t=16s

Low noise road surfacing (LNRS)
LNRS utilises absorbent materials to reduce tyre/road interaction noise or reducing tyre tread impact and shock noise. It is a common standard for highways. For local roads, the application will depend on the specific road condition.

Smart technologies
The name “smart technologies” is generic. Here for environmental protection is the application of virtual reality, big data and artificial intelligence, 3-dimension (3D) geographical information system (GIS) and 3-D photo-realistic model.

  • Virtual reality is a game-changer. In an environmental sense, it mimics the surroundings, and we can add our external idea into the simulated environment to virtually test the practicability. Thoroughly to learn the project environment, the authorities and stakeholders are effortlessly to recognise the potential externality before moving on to urban development.
  • Artificial intelligence enables an automated monitoring system supported by a technology platform that empowers authorised parties to operate through various IT devices, including smartphones and tablets. The system automatically signals the breaches and visually verifies the sources. All data is filed and immediately accessible for use. The system contributes substantial savings in human resources and costs for site monitoring works and enhances information distribution amongst project parties.
  • Law enforcement is to combat environmental crime effectively, random inspection and control are hardly adequate. Target enforcement action and strategy are set to surveillance the risk. The risk-based approach uses a webcam system, an uncrewed aerial vehicle to surveil, and a project website to release surveillance information.
  • Once the data is captured, these data are the lesson learned. It is essential to reposit them, reuse them as reference for future projects. Smart Environmental Assessment System is intelligently capable of learning from past environmental impact assessment (EIA) and performing EIA for projects and planning, analysing public comment, and proposing mitigation measures. Environmental constraints will be identified by retrieving the map previously derived from geospatial data. Automated EM&A checking system and integration of 5G and artificial intelligence technology heighten the enforcement measures. The use of 360 cameras and drones to continuously monitor the work in progress is reasonably applicable.
Video – What will our environmental service be like in the future? : https://www.youtube.com/watch?v=w-1SnZ74thc&t=4s

Do not forget land planning, which is very important from the very beginning. The cradle-to-grave approach starts from design to implementation. The developers’ role falls onto considering the appropriate noise measures before commencing building work. The monitoring and management cause workload and burden. Therefore, the enforcement party should set up a checking mechanism to ensure the developers undertake the mitigation measures.

Video – What the experts tell us about noise control: https://www.youtube.com/watch?v=DzzBBCRbfJE&t=4s

By: ANewR Consulting Limited, a digital environmental consultant headquartered in Hong Kong since 2008. Our expertise has grown into the context of air and water qualities, noise, green building, waste management, and remediation. With extensive know-how in environmental planning and assessment, feasibility study and policy review, ecological design, monitoring, and audit (EM&A), ANewR has matured to be a leading management consultancy. Standing in the digital transformation reign, ANewR has participated in various environmental digital projects – interactive 3D visualisation, immersive automation virtual environment, Virtual reality, automation system, and monitoring platforms.
(Website: https://anewr.com, LinkedIn: ANewR Consulting Group, Twitter: ANewR – Everyday Newer,
YouTube: https://www.youtube.com/channel/UCnpvmxnR9hbNxytSfBdfV8Q/videos)

The authentic practice

Photos above: 4D virtual reality of noise performance of acoustic window and acoustic balcony for the staff training of Environmental Protection Department of HKSAR

The contemporary corporate organisation facilitates information exchange with communicable, interactive platforms. Remarkably, the digital trend is on the way to provide user-friendly and digitised services and training. How do we utilize this digitalisation in environmental training? 

The visualised, virtual reality (VR) illustration is incredibly practical for a metropolitan situation. One of the city’s striking models is 4D VR environmental training – Our prime example of implementing digitalisation into environmental discipline to turn the historical training practice perfect for the environmental staff.  

The idea of digital visualisation is not to discard the tradition; this enhances the generation’s practice to deliver coherent, more favorable results to all. The  4-dimensional generation is strengthening 3-D visual capability with sound effects to create an authentic learning journey. Partaking in the Environmental Protection Department of the HKSAR training project, we have applied the fundamental knowledge of noise and acoustic window and balcony products in the virtual environment into digital tools to create the VR experience with sound effects. Visually being in the environment with the acoustic products installed, the user is standing at one point wearing the VR headset and holding the controller to handle the acoustic products’ open or closure. The user audibly recognises the noise level differences in various scenarios; their acoustic expertise is now turning from imagining the data to a useful background experience. 

We apprehend visual digitalisation in environmental impact training with interactive animation. Next is how to apply an immersive, automatic virtual environment to engage stakeholders to a greater extent.

Video – The 4D movement: https://www.youtube.com/watch?v=zaLDh6f-yxY

By: ANewR Consulting Limited, a digital environmental consultant headquartered in Hong Kong since 2008. Our expertise has grown into the context of air and water qualities, noise, green building, waste management, and remediation. With extensive know-how in environmental planning and assessment, feasibility study and policy review, ecological design, monitoring, and audit (EM&A), ANewR has matured to be a leading management consultancy. Standing in the digital transformation reign, ANewR has participated in various environmental digital projects – interactive 3D visualisation, immersive automation virtual environment, Virtual reality, automation system, and monitoring platforms.
(Website: https://anewr.com, LinkedIn: ANewR Consulting Group, Twitter: ANewR – Everyday Newer,
YouTube: https://www.youtube.com/channel/UCnpvmxnR9hbNxytSfBdfV8Q/videos)

A training about acoustic camera for noise control

We are delighted that Mr. James Choi, Director of ANewR Consulting Group, has presented the webinar about Norsonic acoustic camera application to our client. The real-time demonstration in person has made the webinar lively and informative.

In our second-round acoustic camera training, thanks to Mr. James Choi and Miss Jessica Yam for hosting it and answering questions, ensuring smooth running. James had shared many possible acoustic camera applications in different scenarios to give ideas of how to best use the acoustic camera. Do you find the solution to resolve the noise issue around? Talk to us now.