Contribution
A Toolbox for Filter-Based First- and Higher-Order Edge Diffraction Modeling
* Presenting author
Abstract:
Sound diffraction occurs at corners, objects and openings, prominently affecting occluded and reflected sounds. Particularly in outdoor environments, diffraction at buildings, barriers, and other structures is relevant for developing effective noise mitigation strategies as well as to render realistic soundscapes for applications in virtual and augmented reality. The Universal Diffraction Filter Approximation (UDFA) Toolbox offers a versatile computational tool to integrate diffraction filters in geometrical acoustic simulations. UDFA employs a physically-based, parametric filter model to simulate diffraction effects. The model uses fractional-order low-pass filters to approximate the diffraction at finite edges, with adjustable accuracy including an exact filter representation of the underlying diffraction solutions by Pierce, Kouyoumjian and Pathak (UTD), and Biot-Tostoy-Medwin and Svensson. By directly deriving filter parameters from the underlying geometry and by using a recursive filters, UDFA significantly reduces the computational load. This makes it suitable for real-time applications and large-scale acoustic simulations.Here, we demonstrate several use cases, ranging from the singly diffracted field at an infinite wedge, to double diffraction at a three-sided barrier. Results are compared to measurements and existing approaches like Maekawa’s approximation and sequential application of diffraction filters for the individual edges at the three-sided barrier.UDFA is freely available at https://zenodo.org/records/13771101