Real-time auralization of time-varying sound fields with moving sound sources and listeners

• Applicant: Professor Dr. Michael Vorländer
• Subject Area: Acoustics
• Term: from 2013 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 244441867

This research proposal deals with the real-time auralization of acoustic virtual scenes with fast moving sound sources and listeners. In recent years, sophisticated methods were developed, which allow the physically-based simulation of acoustics in real-time (geometrical acoustics, diffraction models, sound transmission models, etc.). Moving sources and listeners and the resulting Doppler effects have been simulated using simplified approaches only. In case of large distances between sources and listeners, these methods fail to simulate the sound propagation in a plausible way and free of artifacts. Trajectories of moving objects can be altered during runtime only to a limited degree, which puts a strong limitation on the interaction in virtual environments.Based on our long-term experience in this scientific domain, the aim of this project is to enhance recent approaches and to develop new real-time simulation methods for fast moving sources and listeners. The objective is not only to perform the auralization in real-time, enabling a passive listening experience in the virtual scene, but especially to focus on the user interaction, which is essential for Virtual Reality. Movements (trajectories) of all objects in the scene should be modifiable by the user in real-time. In order to achieve this goal new scientific findings are needed in the following areas: a) real-time motion modeling, b) physically-correct computation of sound propagation times in real-time and c) consideration of the temporally-correct parameters in the auralization, which demands the description of the variables in a virtual scene along a temporal history. These results will then be combined into a unified auralization approach. This requires not only an understanding of these individual fields, but also of their distinct interdependencies (motion modeling, sound propagation, scene data structures).The obtained scientific results will be implemented into the existing RWTH Aachen real-time auralization system, enabling it to serve as a tool for enhanced studies in the future (e.g. comprehensive noise scenarios in urban surroundings). The potential sound sources regarded in this project are cars, high-speed trains and aircrafts. Especially for noise research, like traffic and aircraft planning, such virtual environments could prove as a beneficial tool in the future.The initial two-year funding period is needed for the development of all required foundations and the implementation of the software tools. A subsequent third year is dedicated to subjective user studies with statistical psychoacoustic assessments. Here, the potential methods and parameters shall be compared in detail in order to optimize them for the application.

• DFG Programme: Research Grants