An Axisymmetric Object-Based Search for a Flat Compact Dimension

A method is presented to search for a hypertorus symmetry axis by the alignment of distant objects. This offers greater sensitivity than previously proposed object-based methods that rely on accurate true distances. When applied to the catalog of objects with z > 1, we find no evidence for a compact dimension. We deduce a lower limit to the compact dimension size D > 0.9 of the distance to the cosmic horizon. This is consistent with independent constraints from the recent analysis of the WMAP microwave background data.Comment: 12 pages, 10 figures, minor revision, accepted by JCA

Virtual intimacy: Phya as an instrument

Phya is an open source C++ library originally designed for adding physically modeled contact sounds into computer game environments equipped with physics engines. We review some aspects of this system, and also consider it from the purely aesthetic perspective of musical expression

Horizontal sound field reproduction with point sources using distributed constraints

A preliminary investigation is presented of horizontal sound field control using a rectangular array of spherical wave driving sources, with focus on wide area plane wave reproduction. Comparison is made between Wave Field Synthesis and a method based on distributed pressure and velocity constraints. Advantages of the second approach are discussed, and modifications of the both methods are propose

Horizontal sound field reproduction with point sources using distributed constraints

A preliminary investigation is presented of horizontal sound field control using a rectangular array of spherical wave driving sources, with focus on wide area plane wave reproduction. Comparison is made between Wave Field Synthesis and a method based on distributed pressure and velocity constraints. Advantages of the second approach are discussed, and modifications of the both methods are propose

Holophonic synthesis of musical sources

The composition of a soundfield containing complex nearfield sources has interesting musical applications. A method is presented here using freefield expansions about exterior points of a harmonic multipole field. A derivation and verification are included. Binaural rendering is the natural method for displaying such soundfields. Some possible musical applications are discussed

A theoretical analysis of sound localisation, with application to amplitude panning

Below 700Hz sound fields can be approximated well over a region of space that encloses the human head, using the acoustic pressure and gradient. With this representation convenient expressions are found for the resulting Interaural Time Difference (ITD) and Interaural Level Difference (ILD). This formulation facilitates the investigation of various head-related phenomena of natural and synthesised fields. As an example, perceived image direction is related to head direction and the sound field description. This result is then applied to a general amplitude panning system, and can be used to create images that are stable with respect to head direction