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

OpenAIR（开放声学脉冲响应库）网站（www.openairlib.net）是一个用于听觉化的3-D Ambisonic b格式脉冲响应的存储库，以及可用于试听网站上声学调查建筑物的声音的消声记录。这个后续项目是通过与Codemasters合作，开发新的途径来影响这项研究的结果，Codemasters是世界领先的，获得过BAFTA奖的英国电脑游戏公司之一。我们每天居住的环境的声学影响着我们所有人的交流方式，我们的声音，倾听我们周围的环境，以及对过度噪音的反应。例如，在音乐表演空间中，声学的质量对观众和表演者来说都是至关重要的，通过考虑遗产地的声学环境，我们为理解和解释过去提供了新的机会。在测量音乐厅和歌剧院声学特性方面的发展导致了标准化的脉冲响应捕获方法。脉冲响应是给定空间的声学指纹，它独特地定义了特定声源和听众位置的声学特性。从这些测量结果中可以确定设计过程中使用的客观声学参数。使用音频卷积，可以构建空间的虚拟声学表示，这样听众就可以体验到相同的听觉感觉，就好像他们真的在其中一样——这就是“听觉化”，一个衍生自音频的术语，相当于视觉化。OpenAIR的建立是为了促进对3d Ambisonic b格式脉冲响应数据库的更广泛访问，以及进一步扩展和内容管理的能力。目前网站上有来自16个声学空间的数据集，这些数据可以进行非破坏性的探索和处理，并且可以下载各种脉冲响应测量组合。Codemasters提倡在电脑游戏音效设计中使用Ambisonic b格式音频，因为这种3-D音频格式（即带有高度信息的环绕立体声）可以作为一种传递高质量沉浸式音频内容的手段，尽管在家庭播放系统或游戏平台中几乎存在一定的变化。这种对b格式音频使用的共同兴趣凸显了Codemasters团队和OpenAIR项目之间的协同作用。通过OpenAIR，有关声学建模、测量和遗产空间特征的研究问题推动了数据集的内容。然而，编码大师要求内容适合他们的游戏——包括汽车内部的声脉冲响应，开放的景观和特定的氛围记录，以填充他们创建的虚拟环境的声音背景——所有这些都应该是Ambisonic b格式。在这种具有挑战性的现实环境中，需要新的技术来进行有效的测量，OpenAIR需要适应这种新的音频内容，以满足游戏行业的要求。在典型的游戏音频创作工具和工作流程中有效地使用和整合这些音频资产也需要进行研究。该项目将开发适用于开放景观和紧凑室内的新声学测量方法，并重新开发OpenAIR来管理这些新内容。这个项目将产生新的数据集，专门针对游戏行业和Codemasters的需求，这些数据集将用于他们的下一代电脑游戏。我们将能够在更商业化的背景下测试我们研究的可行性，并促进我们两个团队之间的知识转移。数据集的各个方面也将通过OpenAIR网站提供给更广泛的虚拟声学社区。

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.