IMMI Noise Mapping and Prediction

There are circumstances when it is helpful to have detailed information regarding noise propagation. At Acoustic Associates we use the computer based environmental modelling software IMMI from Wolfel. IMMI is used in the generation of noise maps which can map the propagation of multiple noise sources simultaneously to provide an accurate representation of the noise throughout a site. With appropriate site information and drawings (such as Ordinance Survey Maps) accurate 3D models can be generated. The advantage of noise models is that complex noise environments can be realised from multiple sources (road, rail, aircraft and industrial/commercial plant).

Noise maps are often used in the assessment such as:

Benefits of Using Noise Modelling

As IMMI is a 3D acoustic modelling package, representations of noise impact at different heights can be generated, from this; specific glazing solutions can be provided which can differ due to greater distance from the source of noise.

Some circumstances where there is a desire for assessing the introduction of noise mitigation measures; noise modelling is the most cost effective solution. Alternative mitigation measures such as noise barriers (fencing and bunds) and controlling noise at source using enclosures and attenuators, can all be investigated comparatively quickly and low cost.

Mapping for: Residential Planning

Assessment of a site for it?s suitability for residential development under the Planning Policy Guidance 24: Planning & Noise (PPG24) modelling of the acoustic environment can often be invaluable. Models in this case can be used to categorise the site into the NECs which describe the likelihood of gaining planning permission, it is often found that for larger sites parts of the site can fall in to several differing NECs.

Mapping for: Industrial Noise in Residential Areas

Introduction of new industrial noise sources near to residential properties have the potential to cause local residents to complain of noise nuisance and local authorities often ask for assessments to be carried out before granting permission of installing plant. Production of noise maps can be used to estimate the likely noise impact of new plant before installation based upon manufactures acoustic data. Further in the case that proposed plant does not comply with local authority?s requirements this can be used as a tool to select an appropriate alternative unit or mitigation measures.