AES London 2010
Paper Session P14

P14 - Spatial Audio Perception

Monday, May 24, 09:00 — 12:00 (Room C3)
Chair: Russell Mason, University of Surrey - Guildford, Surrey, UK

P14-1 Perceptual Assessment of Delay Accuracy and Loudspeaker Misplacement in Wave Field Synthesis—Jens Ahrens, Matthias Geier, Sascha Spors, Technische Universität Berlin - Berlin, Germany
The implementation of simple virtual source models like plane and spherical waves in wave field synthesis (WFS) employs delays that are applied to the input signals. We present a formal experiment evaluating the perceptual consequences of different accuracies of these delays. Closely related to the question of delay accuracy is the accuracy of the loudspeaker positioning. The second part of the presented experiment investigates the perceptual consequences of improperly placed loudspeakers. Dynamic binaural room impulse response-based simulations of a real loudspeaker array are employed and a static audio scene setup is considered.
Convention Paper 8068 (Purchase now)

P14-2 Perceptual Evaluation of Focused Sources in Wave Field Synthesis—Matthias Geier, Hagen Wierstorf, Jens Ahrens, Ina Wechsung, Alexander Raake, Sascha Spors, Technische Universität Berlin - Berlin, Germany
Wave Field Synthesis provides the possibility to reproduce virtual sound sources located between the loudspeaker array and the listener. Such sources are known as focused sources. A previously published study including an informal listening test has shown that the reproduction of focused sources is subject to audible artifacts, especially for large loudspeaker arrays. The combination of the time-reversal nature of focused sources and spatial sampling leads to pre-echos. The perception of these artifacts is quite different depending on the relative listener position. This paper describes a formal test that was conducted to verify the perceptual relevance of the physical properties found in previous papers.
Convention Paper 8069 (Purchase now)

P14-3 Experiments on the Perception of Elevated Sources in Wave-Field Synthesis Using HRTF Cues—Jose J. Lopez, Maximo Cobos, Technical University of Valencia - Valencia, Spain; Basilio Pueo, University of Alicante - Alicante, Spain
Wave-Field Synthesis (WFS) is a spatial sound reproduction technique that has attracted the interest of many researchers in the last decades. Unfortunately, although WFS has been shown to provide excellent localization accuracy, this property is restricted to sources located on the horizontal plane. Recently, the authors proposed a hybrid system that combines HRTF-based spectral filtering with WFS. This system makes use of the conventional WFS approach to achieve localization in the horizontal plane, whereas elevation effects are simulated by means of spectral elevation cues. This paper provides a review of the proposed method together with a compilation of the last experiments carried out to evaluate the perception of elevated sources in this novel system.
Convention Paper 8070 (Purchase now)

P14-4 Comparison of the Width of Sound Sources in 2-Channel and 3-Channel Sound Reproduction—Munhum Park, Aki Härmä, Steven van de Par, Georgia Tryfou, Philips Research Laboratories - Eindhoven, The Netherlands
In this paper we present the result of listening tests where the width of the sound stage was compared between conventional 2-channel stereophony and 3-channel reproduction with an additional center loudspeaker. When listeners were seated at the axis of symmetry, there was no significant difference between the two cases. In off axis positions there was a clear trend that the perceived image width of the noise is influenced by the way an additional interfering stimulus is reproduced, which was found to depend on the correlation of the noise. The results suggest that the spatial attribute of one sound image may be affected by another, for which possible explanations based on the principles of binaural hearing will be discussed.
Convention Paper 8071 (Purchase now)

P14-5 Study of the Effect of Source Directivity on the Perception of Sound in a Virtual Free-Field—Sorrel Hoare, Alex Southern, Damian Murphy, University of York - York, UK
In the context of soundscape evaluation, an area that has yet to be explored satisfactorily concerns faithful modeling and auralization of outdoor spaces. A common limitation of popular acoustic modeling techniques relates to source characterization, an aspect of which considered here is source directivity. In terms of auralization, source directivity may be linked to perceived spatial sound quality. In a preliminary listening test a selection of audio samples are auralized in a virtual free-field where the directivity pattern of the source is varied. The results confirm the significance of this characteristic on the acoustic perception, thus validating the extension of this research to more complex models.
Convention Paper 8072 (Purchase now)

P14-6 Audio Spatialization for The Morning Line—David G. Malham, Tony Myatt, Oliver Larkin, Peter Worth, Matthew Paradis, University of York - York, UK
The Morning Line is a large-scale outdoor sculpture with a multi-dimensional sound system consisting of 41 small weatherproof main loudspeakers and 12 subs, configured in 6 surround arrays, or "rooms," distributed throughout the sculpture. The irregular nature of these arrays necessitated the use of VBAP panning on the sculpture but when preparing works to be played on it, Ambisonics is more often used. This paper describes the hardware and software developed for the sculpture, theories of spatial audio perception that prompted the design approach, as well as the production facilities provided for the composers whose works are performed on The Morning Line.
Convention Paper 8073 (Purchase now)