Acoustic study of a pyrolysis factory using CadnaA software

Customer: Confidential
Area: Europe
Application : Energy

CadnaA (Computer Aided Noise Abatement Außenlärm) is the most powerful software solution on the market for the calculation, presentation, evaluation and prediction of environmental noise.

The software was developed by the German company DataKustik GmbH, partner of Acoem group, and is available in several versions depending on the requirement:


CadnaA (outdoor noise)

CadnaR (indoor noise)

The Issue

All industrial sites are subject to acoustic standards to protect exposed workers and ensure a limited impact on the surrounding environment.

The customer approached Metravib to carry out an acoustic study and to predict the noise levels in and around its industrial site processing biomass by a fast pyrolysis process (Fast Pyrolysis Bio Oil).

  • In all work areas accessible to workers during their activities, the noise level may not exceed 80 dBA.
  • For the impact on the neighbourhood of the industrial installation, the noise level may not exceed 40 dBA at 200 m from the installation.

Metravib teams thus performed an acoustic modelling based on CadnaA software in order to determine the contribution to airborne noise of each major source, then combine individual source effects and determine the overall noise radiation.

The Solution

Metravib teams started from a 3D representation of the industrial site.


By knowing the main noise sources and the associated acoustic power indicated on the technical notices of the machines, we were able to create a CadnaA model able to estimate the far field noise radiation.

The software is based on the general theory of noise propagation from point sources including the effects of reflection, screening and acoustic absorption (geometric and atmospheric). It takes into account all sources, obstacles, dimensions, diffraction sources, materials, and acoustic properties to calculate ray tracing from each source to the receiver points.

The study allowed to:

  • estimate the sound levels generated by the site equipment
  • provide a map of the operators’ exposure to noise
  • define areas where the individual hearing protective device (IHPD) are necessary
  • identify so-called hot spots (most noisy sources)
  • provide the regulatory authorities with the noise levels that will be generated in the site environment

CadnaA software covers a wide range of applications: acoustic impact of industrial equipment, buildings, factories, wind farms, etc.