Scientific Article

Auralizing arbitrary urban environments including diffraction

Institute for Hearing Technology and Acoustics, RWTH Aachen University, Aachen, Germany

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 22 September 2025
Accepted: 3 April 2026

Abstract

The auralization of urban environments presents significant challenges due to their often convex geometries and dynamic nature involving fast-moving sound sources and receivers. In this work, we introduce an open-source auralization tool specifically designed to address these challenges by efficiently simulating sound propagation in dynamically changing, arbitrarily built environments for diverse environmental sound sources which are characterized by their power and directivity. By leveraging principles from geometrical acoustics and specifically from the uniform theory of diffraction, our method efficiently models mixed reflections and diffraction effects, including higher-order diffraction and Doppler effects. The tool is evaluated with benchmark scenarios intended to stress-test its capabilities. While some limitations related to underlying assumptions – such as infinite-length edges – are identified, these findings underscore its potential for accurately auralizing urban environments. The evaluation highlights the need for the simulation of diffraction and higher-order diffraction effects not only in shadow regions but also around edges, which significantly influences overall sound propagation accuracy. Furthermore, our implementation provides a modular and flexible framework with open interfaces and exchange formats that facilitate integration with existing tools and adaptation to diverse use cases.