Virtual Acoustics for the Built Environment
Nowadays more and more aspects of a building can be experienced while a building is in its design phase with the help of VR simulations. Where traditionally a building was solely described using two-dimensional drawings, it is now possible to walk a fully-fledged three-dimensional visualization of the building. This technological advancement gives architects new possibilities to reinforce and convey their design decisions to clients. These technological advancements, however, are currently limited to the visual representation of buildings, the acoustical representation of a building is still lacking in a sense that at present it is merely represented by means of room acoustical parameter values or simple visual descriptions of acoustical performance. Auralization being the acoustic equivalent of visualization can step in and provide an acoustic experience together with visuals in a VR setting.
Building Acoustics group is currently working on the following research topics under the aim of “creation of a VR-system that can convey the acoustics of a room alongside the visuals to convey acoustical performance during the design phase of a building.”
Development of a Setup for Virtual Reality Auralization
In a traditional VR-setup 3D visuals of an environment are updated real-time according to the position and head orientation of the user. VR can be used in a similar manner with regards to 3D acoustics. The acoustics of a room are defined by the characteristics of the bounding surfaces of that room and the source and receiver (user) positioning and orientation. Using real-time interpolation between precomputed acoustical Impulse Responses of a room (for numerous positions and orientations), the virtual space can be traversed acoustically as well as visually.
Hybrid Modeling for Acoustical Prediction in a Room
Room acoustical prediction software used in VR applications, generally based on geometrical acoustical models, often neglect or oversimplify important wave behaviors of sound in rooms. Wave-based acoustical prediction models can model all relevant wave behavior with high accuracy but have a very high computational demand making them unsuitable for applications in VR acoustics. In hybrid modeling, different modeling methodologies are combined in such a way that accuracy is maintained while computational demand is kept within boundaries.
Psychoacoustics research is vital in understanding to which extent room acoustical phenomena (reflection, interference, and diffraction), geometrical detailing, material properties, and source and receiver properties are perceived. The incorporation of Virtual Reality in psychoacoustic experiments provides audio and visual cues and thus gives the listener a better sense of space. Listening experiments pertaining to sound quality rating and subjective assessment of perceptual attributes provide valuable difference limen that can be used for the development of computationally efficient hybrid models and evaluation of the quality of auralization.