Accurate environmental noise measurement is essential for evaluating noise impacts on both individuals and communities. In this blog, we will delve into the methodologies and instruments employed to measure environmental noise accurately, ensuring a precise assessment. 

Role of Competent Person 

A competent professional with a comprehensive grasp of assessment objectives, sound physics, and proficient utilization of sound measurement tools should perform the noise assessment. Their expertise should extend to occupational noise exposures, result documentation and interpretation, and the evaluation of personal hearing protection. 

Factors to Consider in Noise Assessment 

When performing a noise assessment, it’s crucial to consider several key factors. These encompass the workplace type, the quantity of individuals susceptible to potentially harmful noise exposure, and the Characteristics of environmental noise.  

Noise Measurement Techniques 

For accurate noise measurement, it is recommended to position the sound level meter at the sensitive receiver’s premises. Hand-held integrating sound level meters are the prevalent choice for collecting data on noise levels in various scenarios.  

How to Measure Environmental Noise? 

Here are our exclusive steps on how to measure environmental noise:  

1) Choose Appropriate Equipment:  

Select suitable measurement equipment that aligns with the specific measurement requirements. 

2) Timing and Location:  

Take measurements precisely at the designated time and location relevant to the measurement’s objective. 

3) Consider Operating Conditions:  

Ensure measurements are taken when the premises or activity is operating in a manner that pertains to the measurement’s purpose. This includes accounting for different time periods, such as day, evening, or night. 

4) Representative Time Intervals:  

Guarantee that the chosen measurement time intervals accurately represent the noise from the premises or activity, either by capturing or excluding it. 

5) Address Noise Emission Factors:  

Take necessary measures to consider and account for factors that can influence noise emissions and measurements. Provide robust technical justification and evidence for these actions. 

6) Adhere to Best Practices: 

Follow industry best-practice recommendations for measuring and analysing environmental noise, as outlined in Australian Standard 1055:2018 Acoustics: Description and Measurement of Environmental Noise. 

7) Background Noise Assessment:  

Conduct background noise measurements in accordance with the procedures detailed in the ‘Noise Policy for Industry’ document. 

8) Strategic Measurement Locations:  

Select measurement locations thoughtfully, ensuring they accurately represent the noise source(s) of interest at identified noise-sensitive receivers or assessment points. Justify these selections based on applicable policies, licenses, consents, or notices. 

9) Eliminate Unwanted Noise:  

Take measures to exclude any extraneous noise from the measurements and provide comprehensive information and reasoning for any corrections applied to the recorded noise levels. 

10) Record and Report Diligently:  

Maintain comprehensive records of the instrumentation used, measurement procedures, calibration verifications, measurement intervals, locations, and other pertinent details. When reporting measured noise levels, round them to the nearest integer unless a relevant standard or guideline specifies otherwise. 

Components of a Noise Assessment Report 

A comprehensive noise assessment report is a vital component of effective noise management. It should encompass critical details like the assessment date, the assessor’s identity, equipment specifications, and calibration records. Additionally, it must offer a comprehensive overview of the evaluated environment, machinery, processes, and the workforce. The report’s central focus should be on presenting precise measurements, including noise levels and durations. 

The accuracy of environmental noise measurement holds paramount importance in evaluating its effects on both individuals and communities. When conducted by a skilled professional using appropriate methodologies and tools, a noise assessment can yield invaluable insights for formulating sound noise control and management strategies. 

Enhancing Noise Measurement Analysis 

1) Gain Insights from Noise Measurements:  

Noise measurement analysis offers valuable insights for characterising noise and quantifying contributions from distinct sources. 

2) Justify Noise Calculations:  

Clearly state the rationale behind opting for noise calculations or predictions in lieu of direct measurements. 

3) Employ Appropriate Analysis Tools:  

Utilise tools and methods of analysis that align with the specific circumstances and objectives. 

4) Post-Processing Insights:  

Post-processing involves the analysis of noise measurements captured by a sound level meter. It may encompass statistical analysis, pattern recognition, or machine learning to identify noise sources effectively. 

5) Precision in Frequency Analysis:  

When performing frequency analysis measurements, it’s crucial to adhere to specific standards governing octave-band and fractional-octave-band filters. If deviations occur from these standards, it’s essential to provide a clear justification. 

6) Augmenting with Audio Recordings:  

Audio recordings can complement noise measurements and aid in identifying noise sources within the environment. 

7) Microphone Arrays for Enhanced Insights:  

Employing microphone array systems can provide valuable data concerning the location and direction of noise sources, enhancing the accuracy of your assessment. 

8) Strategic Use of Noise Calculations:  

Noise calculations or predictions can be employed when direct measurements aren’t feasible. However, it’s imperative that these methods are justified and chosen based on necessity, not convenience. 

9) Thorough Measurement Considerations:  

When conducting noise measurements, factors like measurement duration, adjustment for intermittent or variable noise, and comparisons under different operational conditions must be considered. 

10) Alternative Procedures When Necessary:  

Dealing with extraneous noise or measuring noise at locations other than the primary affected noise-sensitive receiver may necessitate alternative procedures, substantiated by well-documented justification. 

11) Adopting Comprehensive Descriptors:  

To accurately characterise and quantify environmental noise, various noise descriptors and measurement time intervals should be utilised. 

12) Competence and Compliance:  

It’s imperative that the person conducting the measurements is highly competent and that the tools and methods of analysis align with the document’s guidelines. 

13) Reporting with Precision:  

When reporting measured noise levels, it’s standard practice to round figures to the nearest integer, unless specific standards or guidelines dictate otherwise. 

14) Comprehensive Record-Keeping 

Effective record-keeping entails documenting measurement techniques, prevailing meteorological conditions, and any alternative procedures applied for noise assessment in locations where direct measurements are unfeasible.” 

Precision Equipment for Environmental Noise Measurement 

Ensuring accuracy in environmental noise measurements within NSW demands the use of specific tools and equipment, including: 

1) Class 1 Sound Level Meter (SLM):  

Environmental noise assessments necessitate the use of a Class 1 sound level meter, adhering to the AS/NZS IEC 61672.1:2019 standards. If older sound level meters are employed, it is imperative to report the standards they meet. 

2) Octave Band Analysis: 

Octave band analysers divide noise into different frequency bands (e.g., one-third octave or octave bands) to assess the frequency content of noise. This technique helps identify the sources and characteristics of noise more precisely. 

3) Community Noise Monitoring:  

This involves deploying multiple noise monitoring stations in a community to collect data over an extended period. It helps assess the overall noise impact on a neighbourhood or region. 

4) Noise Mapping:  

Noise mapping uses geographic information systems (GIS) and data from various monitoring points to create noise maps. These maps visualize noise levels and sources in specific areas, helping urban planners and policymakers make informed decisions. 

5) Impulse Noise Monitoring:  

Impulse noise, such as from industrial equipment or firearms, requires specialized monitoring to capture high-intensity, short-duration sound events. Peak-level sound level meters are often used for this purpose. 

6) Long-Term Noise Monitoring:  

Long-term noise monitoring involves continuous or extended measurements over days, weeks, or months. It provides data on noise patterns, trends, and variations over time. 

7) Frequency Analysis:  

Frequency analysers assess the noise’s frequency spectrum and identify dominant frequencies. This information is crucial for identifying specific sources and addressing noise problems. 

8) Remote Sensing:  

Remote sensing techniques use microphones, sensors, or acoustic cameras to capture and analyse noise from a distance. This is particularly useful for monitoring transportation noise and industrial areas.  

a. Sound Calibrator:  

The sound calibrator must align with the specifications outlined in IEC 60942:2017 and belong to the same class as the sound level meter used. In cases where older sound calibrators are utilized, the standards they meet must be reported. 

b. Reference Sound Source:  

To measure environmental noise accurately, the sound measuring equipment calibration across its complete frequency and dynamic ranges. This calibration should be conducted by a NATA-accredited facility or laboratory, and it must occur regularly. 

c. Additional Recording Instrumentation:  

Any supplementary recording instrumentation applied for the measurement and analysis of environmental noise should also undergo calibration over its entire frequency and dynamic ranges. This calibration should be carried out by a NATA-accredited facility or laboratory. 

Anitech’s experienced Acoustic consultants can help organisations with Environmental noise assessments adhering to the legal requirements. Our team will suggest strategies to implement based on the analysis and help businesses tackle environmental noise issues. 

To talk to our experts, call us today at 1300 802 163 or e-mail –