This article explores the concepts behind noise modelling, its methodologies, and its wide range of applications across various sectors.
<div class="content-body__detail"><section id="section_0" class="entry fr-view"><p class="" data-start="181" data-end="761">Noise is an unavoidable part of modern life. From traffic and construction sites to industrial activities and public events, environmental noise has become a growing concern due to its impact on human health, well-being, and the environment. As urbanisation and industrial development continue to expand, understanding and managing noise pollution has become essential. This is where <strong data-start="565" data-end="584">noise modelling</strong> plays a critical role. It enables researchers, engineers, policymakers, and planners to assess, predict, and mitigate noise levels through scientific methods and digital tools.</p><p class="" data-start="763" data-end="911">This article explores the <strong data-start="789" data-end="824">concepts behind noise modelling</strong>, its <strong data-start="830" data-end="847">methodologies</strong>, and its wide range of <strong data-start="871" data-end="887">applications</strong> across various sectors.</p><h3 class="" data-start="918" data-end="950"><strong data-start="922" data-end="950">What is Noise Modelling?</strong></h3><p class="" data-start="952" data-end="1204"><a href="https://jta.com.au/services/noise-modelling" rel="nofollow">Noise modelling</a> is the process of using mathematical formulas, algorithms, and computer software to simulate and predict noise levels in a specific environment. These models can estimate noise propagation over time and space based on variables such as:</p><ul data-start="1206" data-end="1428"><li class="" data-start="1206" data-end="1280"><p class="" data-start="1208" data-end="1280"><strong data-start="1208" data-end="1234">Source characteristics</strong> (e.g., type of machinery, vehicles, aircraft)</p></li><li class="" data-start="1281" data-end="1356"><p class="" data-start="1283" data-end="1356"><strong data-start="1283" data-end="1311">Environmental conditions</strong> (e.g., terrain, wind, temperature, barriers)</p></li><li class="" data-start="1357" data-end="1428"><p class="" data-start="1359" data-end="1428"><strong data-start="1359" data-end="1381">Receiver locations</strong> (e.g., residential areas, workplaces, schools)</p></li></ul><p class="" data-start="1430" data-end="1567">The primary goal is to <strong data-start="1453" data-end="1494">visualise and quantify sound exposure</strong> so that effective noise control measures can be planned and implemented.</p><h3 class="" data-start="1574" data-end="1613"><strong data-start="1578" data-end="1613">Key Concepts in Noise Modelling</strong></h3><p class="" data-start="1615" data-end="1706">To understand how noise modelling works, it's helpful to grasp a few foundational concepts:</p><h4 class="" data-start="1708" data-end="1737">1. <strong data-start="1716" data-end="1737">Sound Propagation</strong></h4><p class="" data-start="1738" data-end="1870">Noise travels from a source to a receiver through various media (air, water, ground). As it travels, sound energy diminishes due to:</p><ul data-start="1871" data-end="2185"><li class="" data-start="1871" data-end="1943"><p class="" data-start="1873" data-end="1943"><strong data-start="1873" data-end="1885">Distance</strong>: Sound intensity decreases with distance from the source.</p></li><li class="" data-start="1944" data-end="2042"><p class="" data-start="1946" data-end="2042"><strong data-start="1946" data-end="1960">Absorption</strong>: Materials like soil, vegetation, and building surfaces absorb some of the sound.</p></li><li class="" data-start="2043" data-end="2185"><p class="" data-start="2045" data-end="2185"><strong data-start="2045" data-end="2074">Refraction and Reflection</strong>: Weather conditions and topography can bend or reflect sound waves, affecting how far and where noise spreads.</p></li></ul><h4 class="" data-start="2187" data-end="2212">2. <strong data-start="2195" data-end="2212">Decibels (dB)</strong></h4><p class="" data-start="2213" data-end="2452">Noise levels are measured in decibels (dB), a logarithmic unit. The dB scale compresses a large range of sound pressures into a more manageable range. Because it is logarithmic, a 10 dB increase represents a perceived doubling of loudness.</p><h4 class="" data-start="2454" data-end="2497">3. <strong data-start="2462" data-end="2497">Weighting Filters (A-weighting)</strong></h4><p class="" data-start="2498" data-end="2706">The human ear is more sensitive to some frequencies than others. A-weighting (dBA) adjusts measurements to reflect perceived loudness, making it the most commonly used metric in <a href="https://jta.com.au/services/environmental-noise-assessments" rel="nofollow">environmental noise</a> modelling.</p><h4 class="" data-start="2708" data-end="2737">4. <strong data-start="2716" data-end="2737">Modelling Domains</strong></h4><ul data-start="2738" data-end="2907"><li class="" data-start="2738" data-end="2788"><p class="" data-start="2740" data-end="2788"><strong data-start="2740" data-end="2757">Point sources</strong>: Like a loudspeaker or engine.</p></li><li class="" data-start="2789" data-end="2841"><p class="" data-start="2791" data-end="2841"><strong data-start="2791" data-end="2807">Line sources</strong>: Like roads with vehicle traffic.</p></li><li class="" data-start="2842" data-end="2907"><p class="" data-start="2844" data-end="2907"><strong data-start="2844" data-end="2860">Area sources</strong>: Like construction zones or industrial plants.</p></li></ul><h3 class="" data-start="2914" data-end="2943"><strong data-start="2918" data-end="2943">Types of Noise Models</strong></h3><p class="" data-start="2945" data-end="3003">Different noise models are designed for specific contexts:</p><h4 class="" data-start="3005" data-end="3037">1. <strong data-start="3013" data-end="3037">Traffic Noise Models</strong></h4><p class="" data-start="3038" data-end="3106">Used to predict road, rail, and air traffic noise. Examples include:</p><ul data-start="3107" data-end="3272"><li class="" data-start="3107" data-end="3167"><p class="" data-start="3109" data-end="3167"><strong data-start="3109" data-end="3123">CNOSSOS-EU</strong> (Common Noise Assessment Methods in Europe)</p></li><li class="" data-start="3168" data-end="3215"><p class="" data-start="3170" data-end="3215"><strong data-start="3170" data-end="3204">FHWA Traffic Noise Model (TNM)</strong> in the USA</p></li><li class="" data-start="3216" data-end="3272"><p class="" data-start="3218" data-end="3272"><strong data-start="3218" data-end="3262">Calculation of Road Traffic Noise (CRTN)</strong> in the UK</p></li></ul><p class="" data-start="3274" data-end="3369">These models consider vehicle flow, speed, surface type, gradient, and environmental obstacles.</p><h4 class="" data-start="3371" data-end="3406">2. <strong data-start="3379" data-end="3406">Industrial Noise Models</strong></h4><p class="" data-start="3407" data-end="3550">Simulate noise from factories, plants, or machinery. These models account for mechanical equipment, process operations, and layout of the site.</p><h4 class="" data-start="3552" data-end="3589">3. <strong data-start="3560" data-end="3589">Construction Noise Models</strong></h4><p class="" data-start="3590" data-end="3742">Used for temporary but often high-impact projects. They simulate the operation of heavy equipment over time and assess compliance with noise ordinances.</p><h4 class="" data-start="3744" data-end="3777">4. <strong data-start="3752" data-end="3777">Aircraft Noise Models</strong></h4><p class="" data-start="3778" data-end="3952">Such as <strong data-start="3786" data-end="3818">INM (Integrated Noise Model)</strong> or <strong data-start="3822" data-end="3867">AEDT (Aviation Environmental Design Tool)</strong>, simulate aircraft flight paths, altitude, engine thrust, and surrounding geography.</p><h3 class="" data-start="3959" data-end="4000"><strong data-start="3963" data-end="4000">How is Noise Modelling Conducted?</strong></h3><p class="" data-start="4002" data-end="4041">Noise modelling involves several steps:</p><h4 class="" data-start="4043" data-end="4070"><strong data-start="4048" data-end="4070">1. Data Collection</strong></h4><p class="" data-start="4071" data-end="4122">Accurate modelling begins with detailed input data:</p><ul data-start="4123" data-end="4309"><li class="" data-start="4123" data-end="4159"><p class="" data-start="4125" data-end="4159">Type and location of noise sources</p></li><li class="" data-start="4160" data-end="4212"><p class="" data-start="4162" data-end="4212">Operational parameters (e.g., frequency, duration)</p></li><li class="" data-start="4213" data-end="4251"><p class="" data-start="4215" data-end="4251">Topographical maps and land use data</p></li><li class="" data-start="4252" data-end="4309"><p class="" data-start="4254" data-end="4309">Meteorological information (e.g., wind speed/direction)</p></li></ul><h4 class="" data-start="4311" data-end="4342"><strong data-start="4316" data-end="4342">2. Software Simulation</strong></h4><p class="" data-start="4343" data-end="4405">Various software tools are used to simulate noise propagation:</p><ul data-start="4406" data-end="4457"><li class="" data-start="4406" data-end="4418"><p class="" data-start="4408" data-end="4418"><strong data-start="4408" data-end="4418">CadnaA</strong></p></li><li class="" data-start="4419" data-end="4434"><p class="" data-start="4421" data-end="4434"><strong data-start="4421" data-end="4434">SoundPLAN</strong></p></li><li class="" data-start="4435" data-end="4445"><p class="" data-start="4437" data-end="4445"><strong data-start="4437" data-end="4445">IMMI</strong></p></li><li class="" data-start="4446" data-end="4457"><p class="" data-start="4448" data-end="4457"><strong data-start="4448" data-end="4457">ODEON</strong></p></li></ul><p class="" data-start="4459" data-end="4565">These platforms create <strong data-start="4482" data-end="4496">noise maps</strong>, which are graphical representations of sound levels across an area.</p><h4 class="" data-start="4567" data-end="4605"><strong data-start="4572" data-end="4605">3. Validation and Calibration</strong></h4><p class="" data-start="4606" data-end="4764">The model is compared with real-world measurements to ensure its accuracy. Field measurements using sound level meters validate assumptions made in the model.</p><h4 class="" data-start="4766" data-end="4800"><strong data-start="4771" data-end="4800">4. Reporting and Analysis</strong></h4><p class="" data-start="4801" data-end="5002">Noise contours (lines representing equal sound levels) are generated to help visualise noise exposure. The results guide decisions on mitigation measures like barriers, zoning, and construction timing.</p><h3 class="" data-start="5009" data-end="5048"><strong data-start="5013" data-end="5048">Applications of Noise Modelling</strong></h3><p class="" data-start="5050" data-end="5121">Noise modelling has wide-reaching applications across multiple sectors:</p><h4 class="" data-start="5123" data-end="5165"><strong data-start="5128" data-end="5165">1. Urban Planning and Development</strong></h4><p class="" data-start="5166" data-end="5335">Planners use noise modelling to evaluate how new infrastructure projects—such as roads, railways, or residential developments—will impact local soundscapes. It helps in:</p><ul data-start="5336" data-end="5413"><li class="" data-start="5336" data-end="5359"><p class="" data-start="5338" data-end="5359">Designing quiet zones</p></li><li class="" data-start="5360" data-end="5382"><p class="" data-start="5362" data-end="5382">Setting buffer zones</p></li><li class="" data-start="5383" data-end="5413"><p class="" data-start="5385" data-end="5413">Optimising land use planning</p></li></ul><h4 class="" data-start="5415" data-end="5465"><strong data-start="5420" data-end="5465">2. Environmental Impact Assessments (EIA)</strong></h4><p class="" data-start="5466" data-end="5668">Noise modelling is a critical component of EIAs required by government regulations for major construction or industrial projects. It ensures developments comply with national noise limits and standards.</p><h4 class="" data-start="5670" data-end="5705"><strong data-start="5675" data-end="5705">3. Transportation Planning</strong></h4><p class="" data-start="5706" data-end="5745">Transport authorities use modelling to:</p><ul data-start="5746" data-end="5868"><li class="" data-start="5746" data-end="5778"><p class="" data-start="5748" data-end="5778">Design quieter road alignments</p></li><li class="" data-start="5779" data-end="5813"><p class="" data-start="5781" data-end="5813">Implement speed control measures</p></li><li class="" data-start="5814" data-end="5868"><p class="" data-start="5816" data-end="5868">Plan noise barriers along highways or rail corridors</p></li></ul><h4 class="" data-start="5870" data-end="5912"><strong data-start="5875" data-end="5912">4. Occupational Health and Safety</strong></h4><p class="" data-start="5913" data-end="6092">In industries, noise models help assess worker exposure to harmful sound levels and guide the implementation of engineering controls, hearing protection, and work shift rotations.</p><h4 class="" data-start="6094" data-end="6127"><strong data-start="6099" data-end="6127">5. Public Health Studies</strong></h4><p class="" data-start="6128" data-end="6330">Researchers use noise modelling data to study correlations between chronic noise exposure and health outcomes such as stress, sleep disturbance, cardiovascular issues, and reduced cognitive performance.</p><h3 class="" data-start="6337" data-end="6371"><strong data-start="6341" data-end="6371">Challenges and Limitations</strong></h3><p class="" data-start="6373" data-end="6437">While noise modelling is a powerful tool, it has its challenges:</p><ul data-start="6438" data-end="6818"><li class="" data-start="6438" data-end="6515"><p class="" data-start="6440" data-end="6515"><strong data-start="6440" data-end="6460">Data Sensitivity</strong>: Inaccurate input data can lead to unreliable results.</p></li><li class="" data-start="6516" data-end="6627"><p class="" data-start="6518" data-end="6627"><strong data-start="6518" data-end="6547">Environmental Variability</strong>: Weather, terrain, and urban geometry can create unpredictable sound behaviour.</p></li><li class="" data-start="6628" data-end="6703"><p class="" data-start="6630" data-end="6703"><strong data-start="6630" data-end="6644">Complexity</strong>: Advanced models require expert knowledge and calibration.</p></li><li class="" data-start="6704" data-end="6818"><p class="" data-start="6706" data-end="6818"><strong data-start="6706" data-end="6727">Public Perception</strong>: Modelling results may differ from how people experience noise, due to subjective factors.</p></li></ul><h3 class="" data-start="6825" data-end="6862"><strong data-start="6829" data-end="6862">The Future of Noise Modelling</strong></h3><p class="" data-start="6864" data-end="6960">With advances in technology, noise modelling is becoming more sophisticated. Key trends include:</p><ul data-start="6961" data-end="7201"><li class="" data-start="6961" data-end="7008"><p class="" data-start="6963" data-end="7008"><strong data-start="6963" data-end="7008">Real-time noise mapping using IoT sensors</strong></p></li><li class="" data-start="7009" data-end="7068"><p class="" data-start="7011" data-end="7068"><strong data-start="7011" data-end="7068">Integration with BIM (Building Information Modelling)</strong></p></li><li class="" data-start="7069" data-end="7132"><p class="" data-start="7071" data-end="7132"><strong data-start="7071" data-end="7132">Augmented Reality (AR) for visualising sound environments</strong></p></li><li class="" data-start="7133" data-end="7201"><p class="" data-start="7135" data-end="7201"><strong data-start="7135" data-end="7201">Use of AI and big data for more accurate, predictive modelling</strong></p></li></ul><p class="" data-start="7203" data-end="7320">These innovations will make noise modelling more accessible, accurate, and useful for decision-making across sectors.</p><h3 class="" data-start="7327" data-end="7345"><strong data-start="7331" data-end="7345">Conclusion</strong></h3><p class="" data-start="7347" data-end="7673">Noise modelling is more than just a technical exercise—it's a vital tool for creating healthier, quieter, and more sustainable environments. By simulating how sound behaves in our world, it empowers stakeholders to make informed decisions that protect communities, improve quality of life, and support responsible development.</p><p> </p><p class="" data-start="7675" data-end="7855">Whether you're an engineer, urban planner, policymaker, or concerned citizen, understanding noise modelling opens up new possibilities for shaping a better soundscape for everyone.</p><small></small><div class="clear"> </div></section></div>
JTA was established in 1988 under the name of Jeremy Trotman and Associates when Jeremy left the Australian Chamber of Manufacturers (ACM) to commence private practice. The business grew organically and through targeted acquisitions to become JTA Health, Safety & Noise Specialists in 2013. We are proud to be one of Australia’s leading independent workplace consultancies providing pragmatic safety and compliance advice.
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