Acoustic simulations in complex spaces

ICARE functionning principle

Icare is Acoustic or electromagnetic propagation simulation tool developed by CSTB using asymptotic methods (beam tracing). It allows working on complex closed or open 3D environments using beam tracing, ray tracing, particle tracing and time dependent radiosity type simulations. It takes in account reflection and diffraction phenomena on plane or curved surfaces, and handles point and area sources (defined by their acoustic vibration velocity fields).

From the 3D model of the considered scene, the geometric paths are computed. The ICARE simulation methods are complementary to the finite-element method for medium and high frequencies taking into account complex phenomena (diffraction, curved surfaces), independent of the frequency and the materials. The transfer functions between sources and receivers are then computed, including the acoustic (or electromagnetic) properties of materials. It is then possible to get the corresponding impulse responses or echograms and to compute a possible sound synthesis using virtual acoustic tools.

ICARE allows to find acoustic solutions from the design to the completion af a hall, a building, or every closed or opened volume. It is also possible to work on acoustic solutions after the completion of a project.

ICARE model of the Oriental Arts Center Auditorium, Shanghai, China
ICARE model of the National Grand Theatre of China Opera, Beijing, China
Pressure load on a train coach, OSCAR tool
Geometric paths in the Gerland Stadium, Lyon, France

Main features of the software


  • Calculation of frequency response functions (FRF) and impulse responses (RI)
  • Handling of diffraction and diffusion phenomena
  • Precise handling of curved surfaces
  • Possibility to use surface sources defined by the vibration velocity field (GRIM)
  • Interfacing and complementary with finite-element calculations

Practical use :

  • An external data import tool (geometry, ...)
  • A material database management tool
  • A graphical interface (controlling and viewing)
  • Computation core (geometrical and acoustical)
  • A post-processing tool (GUI and command-line)
Practical use of ICARE

Usage examples

1. Computation of transfer function computation with ICARE. Comparisons with BEM in both frequency and time domain.

2. Impulse response calculations

  • Heterogeneous material properties (specular and diffuse reflections).
  • Accurate calculation of early reflections.
  • Determinist calculation of late reflections.
  • Realistic impulse responses auralisation.

3. Computation of acoustic transfer functions in car cabins

4. OSCAR, a dedicated software based on ICARE for comfort and intelligibility in railway coaches

5. Using ICARE radiosity module (car acoustics)

  • Input data: a coarse unstructured mesh of car underhood, absorptions spectra (diffuse alpha) and transmission / insertion losses spectra (TL & IL), power radiated by faces of the engine
  • Results: power radiated by outer shape of the car (solid shapes and holes), SPL at inner and outer microphones

6. Using GRIM within ICARE for interior noise (helicopter cabin) prediction.


The ICARE software is developed and distributed by CSTB. The software is delivered with an installation CD, a dongle and a technical and user manual.
The ICARE software can be used in network with a license server. It can be installed on all computers within the company or institution the software is licensed to.
To purchase please send an e-mail to: nicolas.noe@remove-this.cstb.fr


  • N. Noé, N. Hermant, C. Rougier, I. Schmich, ”A Hybrid Beam and Particle Tracing Solution for Accurate Time Response Prediction of Rooms”, in proceedings of Forum Acusticum, Aalborg, Denmark (2011)
  • N. Noé, M. Vermet ”Application de l’acoustique géométrique à la simulation de la réflexion et de la diffraction par des surfaces courbes”, in proceedings of 10ème Congrès Français d’Acoustique, Lyon, France, 2010.
  • M. Vermet, N. Noé, ”Using asymptotic methods to compute diffracted pressure by curved surfaces”, in proceedings of the 9th ICTCA, Dresden, Germany, 2009.
  • N. Noé, F. Gaudaire, P. Jean, M. Vermet, ”A general ray-tracing solution to reflection on curved surfaces and diffraction by their bounding edges, in proceedings of the 9th ICTCA, Dresden, Germany, 2009.
  • J.-F. Rondeau and al, “SONVERT: hybrid traffic noise simulation approach”, In SAE conference, St Charles, Illinois, USA, 2009.
  • A. Duval an al, “Vehicle Acoustic Synthesis Method 2nd Generation: an effective hybrid simulation tool to implement acoustic lightweight strategies”, In Journee SFA, 2005.
  • J.-F. Rondeau and al, “Vehicle Acoustic Synthesis Method: improving acquisition time by using p-u probes”, In SAE conference, Traverse, Michigan, USA, 2005.
  • N. Noe and al, “A general ray-tracing solution to reflection on curved surfaces and diffraction by their bounding edges”, In ICTCA conference, Dresde, Germany, 2009.
  • M. Vermet and al, “Using asymptotic methods to compute diffracted pressure by curved surfaces”, in ICTCA conference, Dresde, Germany, 2009.
  • J. Caillet and al, “Diagnosis and modelling of interior noise in helicopter cabins”, In 31st European Rotorcraft forum, Florence, Italy, 2005.
  • P. Gabet and al, “Prediction of Acoustic Comfort of a Trainset using Ray-tracing Technology”, In proceedings of Confort Automobile et Ferroviaire, Le Mans, France, 2000.
  • P. Jean and al, “Calculation of Tyre noise radiation with a mixed approach”, Acta Acustica united with Acustica, Volume 94, 2008.

Other informations

OSCAR : a specific software developped from the ICARE core calculation tool.

Download the brochure


Nicolas NOÉ

Tél : +33 (0)2 40 37 20 85

Email : nicolas.noe@remove-this.cstb.fr