From OpenAIR to the Open Air: The Application of Virtual Acoustic Techniques in Landscapes and Novel Environments for Computer Games

The OpenAIR (Open Acoustic Impulse Response Library) website (www.openairlib.net) is a repository of 3-D Ambisonic B-format impulse responses for auralization together with anechoic recordings that can be used to audition the sound of the acoustically surveyed buildings included on the site. This follow-on project is about developing new pathways to impact for the outcomes of this research through a collaboration with Codemasters, one of the world's leading, BAFTA award winning, UK based, computer game companies.

The acoustics of the environments that we inhabit everyday affect us all in terms of how we communicate, project our voice, listen to our surroundings, and respond to excessive noise. For example, in music performance spaces the quality of the acoustics are critical for both audience and performer, and by considering the acoustic environment of heritage sites we make available new opportunities for both understanding and interpreting of the past.

Developments in measuring the acoustic characteristics of concert halls and opera houses have resulted in standardised methods of impulse response capture for auralization. The impulse response is the acoustic fingerprint of a given space, uniquely defining 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. Using audio convolution a virtual acoustic representation of the space can be constructed so that a listener can experience the same aural sensations as if they were actually present within it - this defines auralization, a term derived as the audio equivalent to visualisation.

OpenAIR was established to facilitate wider access to a database of 3-D Ambisonic B-format impulse responses, together with the capability for further expansion and content management. Datasets from 16 acoustic spaces are currently available on the site and this data can be explored and processed non-destructively, with various combinations of impulse response measurements available for download.

Codemasters advocate Ambisonic B-format audio in computer game sound design due to the flexible nature of how this 3-D audio format (that is, surround-sound with height information) might be used as a means of delivering high quality immersive audio content, despite almost certain variation in home playback systems or gaming platform. This common interest in the use of B-format audio highlights the synergy between the Codemasters team and the OpenAIR project. With OpenAIR, research questions in the acoustic modelling, measurement and characterisation of heritage spaces has driven dataset content. Codemasters however, require content that is appropriate for their games - which includes the acoustic impulse response of car interiors, open landscapes and the recording of particular ambiences to populate the sonic background of the virtual environments they create - all of which should be in Ambisonic B-format.

New techniques are needed for effective measurement in such challenging real-world environments and OpenAIR needs to adapt to this new audio content to be of relevance to the requirements of the gaming industry. The effective use and integration of these audio assets in typical game audio authoring tools and workflows also needs to be investigated. This project will develop new means of acoustic measurement appropriate to both open landscapes and compact interiors, and redevelop OpenAIR to manage this new content. This project will result in new datasets specific to the needs of the gaming industry and Codemasters in particular, which will then be used in their next generation computer game titles. We will be able to test the feasibility of our research in a more commercial context and facilitate knowledge transfer between our two teams. Aspects of the datasets will also be made available via the OpenAIR website for the wider virtual acoustics community.

Who will benefit from this research?

This follow-on project is about developing new, previously unforeseen, pathways to potential impact for already existing research, together with the pursuit and development of new user contacts related to the ongoing use of the OpenAIR website.

The main beneficiaries for this research will be Codemasters, one of the world's leading, UK based computer game companies, who we are collaborating with on this project to develop the OpenAIR online resource so that it more directly meets their needs in terms of gathering, archiving and accessing high quality 3-D Ambisonic B-format audio content. This content will include both acoustic impulse responses and specific environmental recordings.

The new learning developed through this collaboration will also have a wider impact on the computer game/game audio industry and this will be enabled through our dissemination of the project's outcomes at the Audio Engineering Society's International Audio for Games conference in 2013 (as embedded in our project plan). This event is the most appropriate forum for knowledge transfer between those working in the game audio industry, related academic research and sound design practice.

The novel content produced and made accessible via OpenAIR will also benefit sound designers (working in TV, film, computer games), making available a wider palette of 3-D surround sound ambiences, environmental sounds and novel acoustic impulse responses.

The final, and perhaps more important beneficiaries will be the consumers of the new entertainment experiences (next generation computer games, TV shows, films) that will be developed by Codemasters and other leading companies as a result of this work.

How will they benefit?

The outcome of this collaboration will provide Codemasters with new high quality 3-D Ambisonic B-format audio content for their next generation releases that will enable them to design more immersive, realistic and engaging game play experiences, and in such a way that the results are standardized across playback systems and gaming platforms.

The game audio industry will benefit from the learning developed in terms of how such content is gathered, and how these complex audio assets are best integrated into typical game audio authoring tools and workflows as part of the sound design and game programming processes.

Sound designers in the wider entertainment industries will be able to access high quality 3-D surround-sound material via the OpenAIR website and integrate it into their working practices, appropriate for current trends in 3-D/HD delivery of multimedia content.

The end users will benefit from enhanced, more immersive, standardized and/or engaging multimedia experiences that will arise from the implementation of the understanding gained and roll-out of this novel audio content.

What will be done to ensure that they benefit?

This project is focused on testing the feasibility of applying the ideas emerging from our research in different business (computer games) and practice (sound design) contexts. The collaboration with Codemasters has been established to realise our common aims and objectives and a plan for implementation will be formalized and agreed in the early stages of the project to ensure that Codemasters and the wider gaming industry will benefit directly. We will disseminate the results of our collaboration through a joint paper at the AES Audio for Games conference maximising the potential for knowledge transfer across multiple audiences. All new procedures and workflow practices will be documented and made available via the OpenAIR website. Developing OpenAIR's flexibility in terms of the content that can be managed and made available will enhance its capabilities and extend the community who might contribute and help to sustain the resource, maximising its benefit and potential for impact beyond its funded life.