Environmental noise modelling with commercial software such as CadnaA, SoundPlan or Predictor has become a standard tool for acoustic consultants. Typically the software implements an engineering model to enable predictions of noise propagation outdoors. When using software it is important to understand the difference between theoretical and engineering models of sound propagation, so that an understanding can be developed of how realistic the model may be. It is also important that the software user understands the meaning and appropriate use of the settings in the model (and hence the software) that control when reflections are included in the calculations, and when they are excluded.
Following his doctorate in environmental noise modelling, Weigang Wei presented his simplified model for sound propagation at Euronoise 2015. You can read more about this model here, and also download the full paper.
A short guide to illustrate the effects of geometry, and how to consider the appropriate number of reflections that should be included in the calculation is discussed here. This summarises the paper presented by Weigang Wei at the Institute of Acoustics conference in 2015.
Felix Larrieu summarises some of the advanced features of CadnaA software for our own benefit; read more here.