TY - CHAP A1 - Brettschneider, Nico A1 - Herder, Jens A1 - de Mooij, Jeroen A1 - Ryskeldiev, Bektur ED - Herder, Jens T1 - Audio vs. Visual Avatars as Guides in Virtual Environments T2 - 21th International Conference on Human and Computer, HC-2018, March 27–28, 2019, Shizuoka University, Hamamatsu, Japan. N2 - Through constant technical progress, multi-user virtual reality is transforming towards a social activity that is no longer only used by remote users, but also in large-scale location-based experiences. We evaluate the usage of realtime-tracked avatars in co-located business-oriented applications in a "guide-user-scenario" in comparison to audio only instructions. The present study examined the effect of an avatar-guide on the user-related factors of Spatial Presence, Social Presence, User Experience and Task Load in order to propose design guidelines for co-located collaborative immersive virtual environments. Therefore, an application was developed and a user study with 40 participants was conducted in order to compare both guiding techniques of a realtime-tracked avatar guide and a non-visualised guide with otherwise constant conditions. Results reveal that the avatar-guide enhanced and stimulated communicative processes while facilitating interaction possibilities and creating a higher sense of mental immersion for users. Furthermore, the avatar-guide appeared to make the storyline more engaging and exciting while helping users adapt to the medium of virtual reality. Even though no assertion could be made concerning the Task Load factor, the avatar-guide achieved a higher subjective value on User Experience. Due to the results, avatars can be considered valuable social elements in the design of future co-located collaborative virtual environments. KW - Virtual Reality KW - Co-located Collaborations KW - Networked Immersive Virtual Environments KW - Head-mounted Display KW - Avatars KW - Lehre Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-23859 UR - https://vsvr.medien.hs-duesseldorf.de/publications/hc2018-avatar/ PB - Hochschule Düsseldorf CY - Düsseldorf ER - TY - CHAP A1 - Amano, Katsumi A1 - Matsushita, Fumio A1 - Yanagawa, Hirofumi A1 - Cohen, Michael A1 - Herder, Jens A1 - Koba, Yoshiharu A1 - Tohyama, Mikio T1 - The Pioneer sound field control system at the University of Aizu Multimedia Center T2 - RO-MAN '96 Tsukuba N2 - The PSFC, or Pioneer sound field control system, is a DSP-driven hemispherical 14-loudspeaker array, installed at the University of Aizu Multimedia Center. Collocated with a large screen rear-projection stereographic display the PSFC features realtime control of virtual room characteristics and direction of two separate sound channels, smoothly steering them around a configurable soundscape. The PSFC controls an entire sound field, including sound direction, virtual distance, and simulated environment (reverb level, room size and liveness) for each source. It can also configure a dry (DSP-less) switching matrix for direct directionalization. The PSFC speaker dome is about 14 m in diameter, allowing about twenty users at once to comfortably stand or sit near its sweet spot. KW - Acoustic reflection KW - Auditory displays KW - Control systems KW - Delay effects KW - Electronic mail KW - Large screen displays KW - Loudspeakers KW - Multimedia systems KW - Reverberation KW - Size control Y1 - 1996 SN - 0-7803-3253-9 U6 - https://doi.org/10.1109/ROMAN.1996.568887 SP - 495 EP - 499 PB - IEEE CY - Piscataway ER - TY - CHAP A1 - Herder, Jens A1 - Cohen, Michael T1 - Sound Spatialization Resource Management in Virtual Reality Environments T2 - ASVA’97 ‐- Int. Symp. on Simulation, Visualization and Auralization for Acoustic Research and Education N2 - In a virtual reality environment users are immersed in a scene with objects which might produce sound. The responsibility of a VR environment is to present these objects, but a system has only limited resources, including spatialization channels (mixels), MIDI/audio channels, and processing power. The sound spatialization resource manager controls sound resources and optimizes fidelity (presence) under given conditions. For that a priority scheme based on human psychophysical hearing is needed. Parameters for spatialization priorities include intensity calculated from volume and distance, orientation in the case of non-uniform radiation patterns, occluding objects, frequency spectrum (low frequencies are harder to localize), expected activity, and others. Objects which are spatially close together (depending on distance and direction) can be mixed. Sources that can not be spatialized can be treated as a single ambient sound source. Important for resource management is the resource assignment, i.e., minimizing swap operations, which makes it desirable to look-ahead and predict upcoming events in a scene. Prediction is achieved by monitoring objects’ speed and past evaluation values. Fidelity is contrasted for Zifferent kind of resource restrictions and optimal resource assignment based upon unlimited dynamic scene look-ahead. To give standard and comparable results, the VRML 2.0 specification is used as an application programmer interface. Applicability is demonstrated with a helical keyboard, a polyphonic MIDI stream driven animation including user interaction (user moves around, playing together with programmed notes). The developed sound spatialization resource manager gives improved spatialization fidelity under runtime constraints. Application programmers and virtual reality scene designers are freed from the burden of assigning and predicting the sound sources. Y1 - 1997 SP - 407 EP - 414 CY - Tokyo ER - TY - JOUR A1 - Amano, Katsumi A1 - Matsushita, Fumio A1 - Yanagawa, Hirofumi A1 - Cohen, Michael A1 - Herder, Jens A1 - Martens, William A1 - Koba, Yoshiharu A1 - Tohyama, Mikio T1 - A Virtual Reality Sound System Using Room-Related Transfer Functions Delivered Through a Multispeaker Array: the PSFC at the University of Aizu Multimedia Center JF - TVRSJ N2 - The PSFC, or Pioneer Sound Field Controller, is a DSP-driven hemispherical loudspeaker array, installed at the University of Aizu Multimedia Center. The PSFC features realtime manipulation of the primary components of sound spatialization for each of two audio sources located in a virtual environment, including the content (apparent direction and distance) and context (room characteristics: reverberation level, room size and liveness). In an alternate mode, it can also direct the destination of the two separate input signals across 14 loudspeakers, manipulating the direction of the virtual sound sources with no control over apparent distance other than that afforded by source loudness (including no simulated environmental reflections or reverberation). The PSFC speaker dome is about 10 m in diameter, accommodating about fifty simultaneous users, including about twenty users comfortably standing or sitting near its ``sweet spot,'' the area in which the illusions of sound spatialization are most vivid. Collocated with a large screen rear-projection stereographic display, the PSFC is intended for advanced multimedia and virtual reality applications. KW - audio signal processing, audio telecommunications KW - auralization KW - calm technology KW - directional mixing console KW - multichannel sound reproduction KW - room-related transfer functions KW - roomware KW - sound localization KW - virtual conferencing environment Y1 - 1998 U6 - https://doi.org/10.18974/tvrsj.3.1_1 VL - 3 IS - 1 SP - 1 EP - 12 PB - J-STAGE ER - TY - CHAP A1 - Cohen, Michael A1 - Herder, Jens ED - Göbel, Martin ED - Landauer, Jürgen ED - Lang, Ulrich ED - Wapler, Matthias T1 - Symbolic representations of exclude and include for audio sources and sinks: Figurative suggestions of mute/solo & cue and deafen/confide & harken T2 - Virtual Environments ’98, Proceedings of the Eurographics Workshop Y1 - 1998 SN - 3-211-83233-5 U6 - https://doi.org/10.1007/978-3-7091-7519-4_23 SP - 235 EP - 242 PB - Springer-Verlag CY - Stuttgart ER - TY - JOUR A1 - Herder, Jens T1 - Tools and Widgets for Spatial Sound Authoring JF - Computer Networks & ISDN Systems Y1 - 1998 VL - 30 IS - 20-21 SP - 1933 EP - 1940 PB - Elsevier ER - TY - CHAP A1 - Martens, William L. A1 - Herder, Jens T1 - Perceptual criteria for eliminating reflectors and occluders from the rendering of environmental sound T2 - 137th Regular Meeting of the Acoustical Society of America and the 2nd Convention of the European Acoustics Association N2 - Given limited computational resources available for the rendering of spatial sound imagery, we seek to determine effective means for choosing whatcomponents of the rendering will provide the most audible differences in the results. Rather than begin with an analytic approach that attempts to predict audible differences on the basis of objective parameters, we chose to begin with subjective tests of how audibly different the rendering result may be heard to be when that result includes two types of sound obstruction: reflectors and occluders. Single-channel recordings of 90 short speech sounds were made in an anechoic chamber in the presence and absence of these two types of obstructions, and as the angle of those obstructions varied over a 90 degree range. These recordings were reproduced over a single loudspeaker in that anechoic chamber, and listeners were asked to rate how confident they were that the recording of each of these 90 stimuli included an obstruction. These confidence ratings can be used as an integral component in the evaluation function used to determine which reflectors and occluders are most important for rendering. KW - audio rendering KW - first-order reflection KW - human perception KW - level of detail KW - occluder KW - sound spatialization resource management Y1 - 1999 PB - Acoustical Society of America, European Acoustics Association CY - Berlin ER - TY - CHAP A1 - Martens, William L. A1 - Herder, Jens A1 - Shiba, Yoshiki T1 - A filtering model for efficient rendering of the spatial image of an occluded virtual sound source T2 - 137th Regular Meeting of the Acoustical Society of America and the 2nd Convention of the European Acoustics Association N2 - Rendering realistic spatial sound imagery for complex virtual environments must take into account the effects of obstructions such as reflectors and occluders. It is relatively well understood how to calculate the acoustical consequence that would be observed at a given observation point when an acoustically opaque object occludes a sound source. But the interference patterns generated by occluders of various geometries and orientations relative to the virtual source and receiver are computationally intense if accurate results are required. In many applications, however, it is sufficient to create a spatial image that is recognizable by the human listener as the sound of an occluded source. In the interest of improving audio rendering efficiency, a simplified filtering model was developed and its audio output submitted to psychophysical evaluation. Two perceptually salient components of occluder acoustics were identified that could be directly related to the geometry and orientation of a simple occluder. Actual occluder impulse responses measured in an anechoic chamber resembled the responses of a model incorporating only a variable duration delay line and a low-pass filter with variable cutoff frequenc KW - audio rendering KW - first-order reflection KW - human perception KW - occluder Y1 - 1999 PB - Acoustical Society of America, European Acoustics Association CY - Berlin ER - TY - CHAP A1 - Ishikawa, Kimitaka A1 - Hirose, Minefumi A1 - Herder, Jens T1 - A Sound Spatialization Server for a Speaker Array as an Integrated Part of a Virtual Environment T2 - IEEE YUFORIC Germany 98 N2 - Spatial sound plays an important role in virtual reality environments, allowing orientation in space, giving a feeling of space, focusing the user on events in the scene, and substituting missing feedback cues (e.g., force feedback). The sound spatialization framework of the University of Aizu, which supports number of spatialization backends, has been extended to include a sound spatialization server for a multichannel loudspeaker array (Pioneer Sound Field Control System). Our goal is that the spatialization server allows easy integration into virtual environments. Modeling of distance cues, which are essential for full immersion, is discussed. Furthermore, the integration of this prototype into different applications allowed us to reveal the advantages and problems of spatial sound for virtual reality environments. KW - distance cue KW - loudspeaker array KW - psychoacoustic KW - sound spatialization server Y1 - 1998 UR - http://vsvr.medien.hs-duesseldorf.de/publications/ve98-spatial-server/welcome.html PB - IEEE CY - Stuttgart ER - TY - CHAP A1 - Herder, Jens A1 - Yamazaki, Yasuhiro T1 - A Chatspace Deploying Spatial Audio for Enhanced Conferencing T2 - Third International Conference on Human and Computer KW - VSVR Y1 - 2000 SP - 197 EP - 202 PB - University of Aizu CY - Aizu-Wakamatsu ER -