Auralization of Urban Environments - Real-time Simulation of Diffraction

• Applicant: Professor Dr. Michael Vorländer
• Subject Area: Acoustics
• Term: from 2015 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 274368052

Within the call for proposals from DFG and FAPERJ, a research group from Brazil (UFRJ, Universidade Federal Rio de Janeiro) and a research group from Germany (RWTH, Rheinisch-Westfälische Technische Hochschule Aachen) apply for a joint project. The objective of this proposal is an advanced methodology to achieve a 3D sound simulation (auralization) in the application of noise propagation and assessment: Auralization of Urban Environments. In particular, the German group will mainly focus on real-time simulation of sound diffraction in urban environments. The simulation methodology will be based on Geometrical Acoustics. It refers to standard noise mapping calculations but it will extend the established procedures by frequency-dependent diffraction at finite edges represented as digital filters. The first step will be identifying the major propagation paths based on a scene geometry. Concentrating on these contributions will decrease the computational effort to derive diffraction filters from analytic models (Biot-Tolstoy, Medwin, Svensson, etc.). A strategy to control the computation efforts will be pursued by implementing approximations to efficiently model diffraction (Maekawa, UTD, Svensson, etc.). These basic diffraction objects have their algorithmic counter parts in likewise basic operations, which will be solved efficiently using shared-memory parallelization. The distribution handling of these basic calculations to the available resources (units of a multicore processor, nodes of a PC-cluster) require intelligent scheduling. In order to simplify the exchange of geometrical input data, the German and Brazilian researchers will settle on established data formats, such as CityGML. By making it possible to integrate these formats as basis for the sound propagation simulation and auralization, already existing data can be used directly (e.g. cadastral maps and digital representations of large cities). The Brazilian research team will also focus on appropriately visually capturing and acoustically recording urban dynamics. In a joint effort, the results of the Brazilian and German accomplishments will be finally evaluated and compared numerically and psycho-acoustically using both the very different city models and noise situations in Aachen and Rio de Janeiro.

• DFG Programme: Research Grants
• International Connection: Brazil
• Partner Organisation: Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro
• Cooperation Partner: Professor Dr. Julio Cesar Boscher Torres