v3.1, 20040329, ME
Session B Saturday, May 8 09:30 h–11:00 h
SPATIAL PERCEPTION AND PROCESSING—PART 1
(focus on spatial perception in virtual space)
Chair: Günther Theile, Institut für Rundfunktechnik, Munich, Germany
B-1 Unidimensional Simulation of the Spatial Attribute “Ensemble Depth” for Training Purposes—Part 2: Creation and Validation of Reference Stimuli—Tobias Neher, Tim Brookes, Francis Rumsey, University of Surrey, Guildford, Surrey, UK
In the context of devising a spatial ear-training system, a study into the perceptual construct “ensemble depth” was executed. Based on the findings of a pilot study into the auditory effects of early reflection (ER) pattern characteristics, exemplary stimuli were created. Changes were highly controlled to allow unidimensional variation of the intended quality. To measure the psychological structure of the stimuli and hence evaluate the success of the simulation, multidimensional scaling (MDS) techniques were employed. Supplementary qualitative data were collected to assist with the analyses of the perceptual (MDS) spaces. Results show (1) that syllabicity of source material (rather than ER design) is crucial to depth hearing and (2) that unidimensionality was achieved, thus suggesting the stimuli to be suitable for training purposes.
B-2 Audibility Thresholds of Spatial Variations in a Single Acoustic Reflection—Marinus M. Boone, Hiske W. Helleman, Technical University of Delft, Delft, The Netherlands
When recording impulse responses of a concert hall for later processing in a spatial audio reproduction system such as Wave Field Synthesis (WFS), the question arises as to how far these impulse responses can be used for different source positions without a loss in spatial perception. A preliminary study has been carried out to find the threshold of audibility of spatial variations in the position of a single reflection. It was found that the minimum audible distance variation of a single reflection is 1 to 2 m, or 5 to 10 degrees, depending on the spatial configuration and whichever is the largest. From that result preliminary conclusions can be drawn about the necessary resolution in recording and synthesis of reflection patterns for WFS rendering or other spatial reproduction systems.
B-3 Spatial Perception in Wave Field Synthesis Rendered Sound Fields: Distance of Real and Virtual Nearby Sources—Helmut Wittek1, 2, Stefan Kerber1, 3, Francis Rumsey2, Günther Theile1
1 Institut für Rundfunktechnik, Munich, Germany
2 University of Surrey, Guildford, Surrey, UK
3 Technical University of Munich, Munich, Germany
Wave Field Synthesis is capable of reproducing a sound field by means of loudspeaker arrays. It is desired to make a copy of the original sound field in order to create a virtual sound field with the same properties. It has been shown that the characteristics are similar but not congruent, which leads to the question of what the agreements and differences are with regard to auditory perception. Considerations and experiments are made to illuminate the case of distance perception of virtual sources, and, in particular, the role of the curvature of the wave front for distance perception.
