Research_
Spatial Audio and Acoustics
Improving the quality of the sound environment
We research sound in the built environment and how sound and acoustics affect people, to improve environmental sound and acoustics, audio systems and sound design, and the auditory experience for building occupants.
Acoustics is one of the main contributors to the quality of the built environment, with sound having a profound effect on human communication, comfort, productivity and enjoyment. This poses many challenges in architecture because of the significant sizes and enormous range of audible sound wavelengths, the permeability of building fabric to sound, and the many ways in which sound is perceived (eg, as speech, music, noise and soundscape). Consequently, there are many problems yet to be solved about how to optimise the acoustics of spaces for their human occupants, and answering related research questions requires expertise in many areas, including physical acoustics, psychoacoustics, and spatial audio.
While conventional audio systems are a part of almost every building, playing a substantial role in supporting human activity, work employing spatial audio systems typically involves advanced signal processing to control and analyse sound fields, to simulate and deepen understanding of sound in the built environment.
Our group supports research and teaching concerned with sound in the built environment. We conduct advanced research on problems of acoustics and audio applications, and contribute to improving the sound environment in which we live.
The Indoor Environmental Quality Laboratory provides infrastructure for our research on how acoustics affect comfort and productivity. It is equipped with an integrated multichannel audio system for simulating sound fields (such as masking noise, external sources of sound, and human-like talkers).
Our approach to research
Our research is focused on the ways in which sound and acoustics affect people. Psychoacoustics – the field of research relating characteristics of audio (or auditory) signals to human sensation, perception and cognition – plays an important role in many of our research projects. Psychoacoustics is often used to assess sound quality, including the quality of sound environments, room acoustics, audio systems and auditory displays. We develop and use computational models to predict the human experience of sounds and acoustic systems. This allows us to improve the practice of sound design in the built environment.
Sound field simulation, or auralization, is an important tool for research in psychoacoustics, and methods for simulation are part of our research. Our research uses:
- binaural systems (eg headphone and loudspeakers with cross-talk cancellation)
- oral-binaural systems
- multi-loudspeaker installations.
We can create highly realistic simulations of acoustic environments and we have developed methods of measuring acoustic environments that are suited to particular simulation approaches. Our research mainly uses scientific or empirical methods, although some research also involves artists or designers.
We have developed a variety of measurement and analysis methods. Some are focused on psychoacoustic algorithms, and we have published software (PsySound and AARAE) to implement our methods. In-room acoustics, spatial measurement techniques have developed quickly over the past decade. Our work uses both loudspeaker arrays and microphone arrays.
Research in architectural acoustics is supported by physical and computational modelling. The school’s Design Modelling and Fabrication Lab provides substantial capabilities for physical modelling, for example, using robot fabrication, CNC milling, laser cutting, 3D printing, or manual fabrication. Computational modelling includes ray-based and wave-based acoustic modelling, including boundary element method and finite difference time domain method using high-performance computing facilities.
Engagement
We welcome opportunities to collaborate with community groups, businesses, government and other external parties in formally funded research or through consultancy.
Please email Associate Professor Densil Cabrera.
Current funded projects
ARC DP DP160103978
Australian Research Council (ARC)
Professor Richard de Dear, Dr Densil Cabrera, Dr Jungsoo Kim
Without internal walls, open-plan offices are designed to make people interact more frequently and therefore be more collaborative and productive. Yet there is a high level of dissatisfaction with open-plan layout because of frequent distraction by background speech from co-workers, which has been shown to significantly decrease work performance and productivity. This project aims to better understand how irrelevant speech in open-plan offices affects the occupants’ cognitive performance and creates annoyance. The intended outcomes are the development of powerful new tools to measure, model and predict the degree of speech distraction at work, enabling establishment of new international standards.
Our researchers
- Associate Professor Densil Cabrera
- Honorary Associate Dr Manuj Yadav
- Mr Jonothan Holmes
Publications
- Cabrera, D., Miranda, L., Jimenez, D., Edser, C., & Martens, W. L. (2015). A Facility for Simulating Room Acoustics, Employing a High Density Hemispherical Array of Loudspeakers. Acoustics Australia, 43(1), 77-81.
- Martens, W. L., Cabrera, D., Miranda, L., & Jimenez, D. (2015). Potential and Limits of a High-Density Hemispherical Array of Loudspeakers for Spatial Hearing and Auralization Research. Journal of Applied Mathematics and Physics, 3(02), 240.
- Jeon, J., Kim, Y., Lim, H., Cabrera, D. (2015). Preferred positions for solo, duet, and quartet performers on stage in concert halls: In situ experiment with acoustic measurements. Building And Environment, 93(P2, November 01, 2015), 267-277.
- Cabrera, D., Lee, D., Leembruggen, G., & Jimenez, D. (2014). Increasing robustness in the calculation of the speech transmission index from impulse responses. Building Acoustics, 21(3), 181-198.
- Cabrera, D., Jimenez, D., & Martens, W. L. (2014, November). Audio and Acoustical Response Analysis Environment (AARAE): a tool to support education and research in acoustics. In Proceedings of Internoise.
- Reinhardt, D., Cabrera, D., Niemelä, M., Ulacco, G., & Jung, A. (2014). TriVoc. In Robotic Fabrication in Architecture, Art and Design 2014 (pp. 163-180). Springer International Publishing.
- de Dear, R., Nathwani, A., Cândido, C., & Cabrera, D. (2013). The next generation of experientially realistic lab-based research: The University of Sydney's Indoor Environmental Quality Laboratory. Architectural Science Review, 56(1), 83-92.
- Cabrera, D., Miranda, L., Crow, R., & De Dear, R. (2013, June). Audio and acoustic design of the University of Sydney′ s Indoor Environmental Quality Laboratory. In Proceedings of Meetings on Acoustics (Vol. 19, No. 1, p. 015016). Acoustical Society of America.
- Jofre, L. A. M., Cabrera, D., Yadav, M., Sygulska, A., & Martens, W. (2013, June). Evaluation of stage acoustics preference for a singer using oral-binaural room impulse responses. In Proceedings of Meetings on Acoustics (Vol. 19, No. 1, p. 015074). Acoustical Society of America.
- Lee, D., Cabrera, D., & Martens, W. L. (2012). Accounting for listening level in the prediction of reverberance using early decay time. Acoustics Australia, 40(2), 103-110.
- Lee, D., Cabrera, D., & Martens, W. L. (2012). The effect of loudness on the reverberance of music: Reverberance prediction using loudness models. The Journal of the Acoustical Society of America, 131(2), 1194-1205.
- Yadav, M., Cabrera, D., & Martens, W. L. (2012). A system for simulating room acoustical environments for one’s own voice. Applied Acoustics, 73(4), 409-414.
