Wrapped Into Sound: Development of the Immersive Audio Quality Inventory (IAQI)

Although virtual reality, video entertainment, and computer games are dependent on the three-dimensional reproduction of sound (including front, rear, and height channels), it remains unclear whether 3D-audio formats actually intensify the emotional listening experience. There is currently no valid inventory for the objective measurement of immersive listening experiences resulting from audio playback formats with decreasing degrees of immersion (from mono to stereo, 5.1, and 3D). The development of the Immersive Audio Quality Inventory (IAQI) could close this gap. An initial item list (N = 25) was derived from studies in virtual reality and spatial audio, supplemented by researcher-developed items and items extracted from historical descriptions. Psychometric evaluation was conducted by an online study (N = 222 valid cases). Based on controlled headphone playback, participants listened to four songs/pieces, each in the three formats of mono, stereo, and binaural 3D audio. The latent construct “immersive listening experience” was determined by probabilistic test theory (item response theory, IRT) and by means of the many-facet Rasch measurement (MFRM). As a result, the specified MFRM model showed good model fit (62.69% of explained variance). The final one-dimensional inventory consists of 10 items and will be made available in English and German.

Immersive Audio Application Coding Proposal to the SBTVD TV 3.0 Call for Proposals

In July 2020 the Brazilian Terrestrial Television System Forum (SBTVD) has issued a Call for Proposals (CfP) for their next-generation digital TV system called TV 3.0. Fraunhofer IIS and ATEME have proposed the MPEG-H Audio system, based on the open international standard ISO/IEC 23008-3, MPEG-H 3D Audio, as a candidate technology for the Application Coding component of SBTVD TV 3.0. The submitted proposal specifies a new Application Programming Interface (API) enabling applications to make use of the nextgeneration interactivity features of the MPEG-H Audio system. This paper provides a detailed description of the proposed API, as well as the submitted JavaScript implementation, and the architecture of the prototype system. Additionally, the paper outlines the proposed evaluation process demonstrating how the MPEG-H Audio system fulfills the TV 3.0 Application Coding requirements for 3D object-based immersive audio interaction and emergency warning information delivery

Immersive audio-visual scene reproduction using semantic scene reconstruction from 360 cameras

As personalised immersive display systems have been intensely explored in virtual reality (VR), plausible 3D audio corresponding to the visual content is required to provide more realistic experiences to users. It is well known that spatial audio synchronised with visual information improves a sense of immersion but limited research progress has been achieved in immersive audio-visual content production and reproduction. In this paper, we propose an end-to-end pipeline to simultaneously reconstruct 3D geometry and acoustic properties of the environment from a pair of omnidirectional panoramic images. A semantic scene reconstruction and completion method using a deep convolutional neural network is proposed to estimate the complete semantic scene geometry in order to adapt spatial audio reproduction to the scene. Experiments provide objective and subjective evaluations of the proposed pipeline for plausible audio-visual VR reproduction of real scenes.

Enhancing Audio Description: Inclusive Cinematic Experiences Through Sound Design

This paper explores the creation of an alternative to traditional Audio Description for visually impaired film and television audiences. The Enhanced Audio Description (EAD) methods utilise sound design as the main vehicle for accessibility and advocate for the integration of accessibility practices to filmmaking workflows. Moreover, this integrated strategy results in an organic form of accessibility that can cater for both visually impaired and sighted audiences, championing inclusive cinematic experiences. The present article reflects on the discussions held during focus groups in which mixed audiences of visually impaired and sighted people watched the same film, with the same EAD soundtrack over headphones. The discussions highlight the potential of the format as an example of universal design and accessible filmmaking, which can be enjoyed regardless of audience’s sight condition and can be offered alongside traditional Audio Description (AD) in order to cater for different aesthetic preferences. Lay summary Audio Description (AD) is a third person commentary added to film and television productions to make them accessible for visually impaired audiences. Traditionally, AD is added to productions after they have been completed, meaning that the creative and accessibility teams do not work together to produce the accessible version of the production. This paper explores an alternative to traditional AD, called Enhanced Audio Description (EAD), whose methods are integrated to filmmaking workflows. EAD moves away from a focus on verbal descriptions and instead focuses on sound design strategies. In EAD the traditional third person commentary is replaced by the combination of three techniques. The first is the addition of sound effects to provide information on actions, convey abstract scenes as well as indicate time, place, and the presence of characters. The second is the use of binaural audio (3D audio over headphones) to convey the position of characters and objects portrayed on the screen. Finally, first-person narration is used to portray feelings, gestures, colours as well as certain actions. The application of EAD methods results in a form of accessibility that can cater for both visually impaired and sighted audiences, championing inclusive cinematic experiences. Focus groups with audiences of visually impaired and sighted people demonstrated the potential of the format to be widely enjoyed, and to be offered alongside traditional Audio Description (AD) in order to provide accessible experiences which cater for different aesthetic preferences.

3D sound spatialization with game engines: the virtual acoustics performance of a game engine and a middleware for interactive audio design

This study analyses one of the most popular game engines and an audio middleware to reproduce sound according to sound propagation physics. The analysis focuses on the transmission path between the sound source and the receiver. Even if there are several ready-to-use real-time auralization platforms and software, game engines' use with this aim is a recent study area for acousticians. However, audio design needs with game engines and the limits of their basic releases require additional tools (plugins and middleware) to improve both the quality and realism of sound in virtual environments. The paper discusses the use of Unreal Engine 4 and Wwise's 3D audio production methods in a set of different test environments. It assesses their performance in regard to a commercial geometrical acoustics software. The results show that the investigated version of the game engine and its sound assets are insufficient to simulate real-world cases and that significant improvements can be achieved with use of the middleware.

Characterising thermal water circulation in fractured bedrock using a multidisciplinary approach: a case study of St. Gorman’s Well, Ireland

A hydrogeological conceptual model of the source, circulation pathways and temporal variation of a low-enthalpy thermal spring in a fractured limestone setting is derived from a multidisciplinary approach. St. Gorman’s Well is a thermal spring in east-central Ireland with a complex and variable temperature profile (maximum of 21.8 °C). Geophysical data from a three-dimensional(3D)audio-magnetotelluric(AMT) survey are combined with time-lapse hydrogeological data and information from a previously published hydrochemical analysis to investigate the operation of this intriguing hydrothermal system. Hydrochemical analysis and time-lapse measurements suggest that the thermal waters flow within the fractured limestones of the Carboniferous Dublin Basin at all times but display variability in discharge and temperature. The 3D electrical resistivity model of the subsurface revealed two prominent structures: (1) a NW-aligned faulted contact between two limestone lithologies; and (2) a dissolutionally enhanced, N-aligned, fault of probable Cenozoic age. The intersection of these two structures, which has allowed for karstification of the limestone bedrock, has created conduits facilitating the operation of relatively deep hydrothermal circulation (likely estimated depths between 240 and 1,000 m) within the limestone succession of the Dublin Basin. The results of this study support a hypothesis that the maximum temperature and simultaneous increased discharge observed at St. Gorman’s Well each winter is the result of rapid infiltration, heating and recirculation of meteoric waters within a structurally controlled hydrothermal circulation system.