The Virtual Acoustics and Auralization Database

The buildings we inhabit everyday affect us all in terms of how we communicate, project our voice, listen to our environment, and respond to excessive noise. The sound of the built environment and good acoustic design is critical in modern architectural practice and this is in part based on a clear understanding of what has gone before, hence the fascination with, for example, the great concert halls and opera houses of Europe and their influence on modern design practices. More recently there has also been interest in the research and preservation of the acoustics of heritage sites which presents additional opportunities for both understanding and interpretation of the past as well as developing new audiences for work of this nature through novel virtual reality style interaction. Acoustic data also provides additional opportunities to inform issues relating to preservation and measurement of degradation or change over time. A key example being the destruction by fire of the Gran Teatro La Fenice in Venice in 1996, and its subsequent restoration, where acoustic measurements taken just prior to the fire played a key role in the acoustic redesign. The main application for this data however is in music production, where the acoustic effects of real spaces, played back around a listener or audience over many loudspeakers presents exciting, dramatic and highly realistic acoustic environments in which recorded musical works can be contextualised.

Developments in measuring the acoustics of concert halls and opera houses have resulted in standardised methods of impulse response capture for a wide variety of auralization applications. The impulse response is the acoustic fingerprint for a given space and uniquely defines its acoustic characteristics for particular sound source and listener positions. From these measurements objective acoustic parameters, as used in the design process can be determined. The result can also be used to create a virtual acoustic representation of the space so that a listener can experience the same aural sensations remotely as if they were actually there - this is what auralization is, a term derived as the audio equivalent to visualisation. These techniques are now commonly used in both architectural acoustics and in the field of acoustic archaeology (archeoacoustics). Measurements of existing real environments can be further extended by analogous techniques employed for virtual sites that only exist as part of a 3D computer model - these latter techniques are highly applicable in the field of acoustic archaeology where an existing site may have little resemblance to how it looked or sounded at the height of its use.

Researchers at York currently have extensive acoustic survey data for 12 actual sites and 2 3D computer models. This work was initiated through an AHRB/ACE Science/Heritage Fellowship in 2004 but to date only a small part of this work has been made more widely available. The aim of this project is to produce a sustainable online repository for this data and a more general resource for research in virtual acoustics. This will consist of a database of high-resolution acoustic impulse responses for sites across and beyond the UK, starting with the 14 that have currently already been completed. These measurements will be supported with software to enable third parties to conduct their own acoustic surveys, upload the impulse responses obtained and audition the final results using specially recorded anechoic audio material that will also be made available.

This resource will have significant impact in music production as well as in the fields of architectural/archaeological acoustic studies. There will also be related impact in the field of audio engineering where auralization and its effective delivery to the listener are key issues relating to, for example, the development of interactive entertainment and communication, high definition television, and computer game audio development.

Who will benefit from this research?

The main beneficiaries for this research will be those computer musicians and composers interested in working with the highest quality or most realistic options for rendering acoustic space. Additional beneficiaries include acoustic consultants working in industry who will be able to use new software, acoustic data and recordings to inform their work with the possibility of demonstrating new or extended auralization techniques for their clients.
Also benefitting will be the owners and custodians of the sites themselves. An acoustic snapshot of the space in question will provide a record for posterity which may be of use for future restoration or act as an additional means of measuring degradation or change. This data, if appropriate, may be used in the development of visitor interactives, audio guides or VR representations.
Finally, the new experiences and enhanced understanding that will result from this work together with the development of new means for interacting with a site through its acoustic representation will ultimately be of benefit to the wider public as the visitors to these sites, and the consumers of the new music and interactive virtual experiences that may well result.

How will they benefit?

The outcome of this research will provide computer musicians with an expanded toolset for the capture, exploration and auditioning of acoustic spaces. The developing library of acoustic impulse responses will help to expand creativity through an increased palette of acoustic environments in which musical works might be contextualised.
For acoustic consultants and architectural acousticians the additional data, robustly measured and validated can be used to inform current design strategies through a better understanding of existing practice. New software will enable beneficiaries to conduct their own measurement work more effectively and the expanded library of anechoic material will be invaluable in developing new auralization demonstrations.
Site owners and custodians will have new data available to inform curatorial, building management and environmental decision making. Where the acoustic environment is more critical (e.g. concert halls, performance venues, classrooms, public spaces), the acoustic data will provide an invaluable record of current performance against which possible future changes, planned improvements or natural degradation might be measured.
Auralization and VR applications, audio guides, or site interactives will demonstrate the potential for new means of engagement and provide another important dimension alongside more usual visual presentations. Hence there is also the potential for developing new audiences for these sites.
The public will ultimately benefit from the development of new musical works, the opportunities to listen to and experience important architectural or archaeological spaces in new ways, the potential for new means of visitor understanding and engagement with these sites and through their acoustic preservation for future generations.

What will be done to ensure that they benefit?

This whole project is focused on the wider dissemination of this existing and future work and the valuable resource that is generated as a result. All aspects will be documented and made available online for all potential users to interact with. All new procedures and workflow practices will be tested for efficiency and effective ease of use. To highlight the potential benefits of acoustic simulation for a variety of applications and as a means to explore, audition and interact with acoustic space, a demonstration of walk-through auralization will be prepared and made available for all visitors to the site. We will make use of the University of York press office to announce the launch of the completed website and target potential user groups through