A Spherical Basis Function Neural Network for Modeling Auditory Space

Dr. Rick Jenison
Department of Psychology
University of Wisconsin-Madison
jenison@wavelet.psych.wisc.edu

2:30 pm Fri. Nov. 4 in 2310 Computer Sciences and Statistics Bldg.

This talk will describe a novel neural network for approximation problems on the sphere. The von Mises basis function is introduced, whose activation depends on spherical rather than Cartesian input coordinates. Spherical data arise in many areas of science such as geophysics and meteorology, and projection geometry has been the focus of cartographic interest for problems involving a transformation of the spherical earth into a planar map. The architecture of the von Mises Basis Function (VMBF) neural network will be presented along with the corresponding gradient-descent learning rules for optimizing the position and shape of the spherical basis functions. The VMBF neural network has been used to solve a particular spherical problem of approximating acoustic parameters used to model perceptual auditory space. This model uses digital signal processing techniques to synthesize a virtual auditory environment under headphone listening conditions. Advantages of using VMBFs over standard Radial Basis Functions (RBFs) for spherical approximation will be discussed.