Exploration of a Biologically Inspired Model for Sound Source Localization In 3D Space

Sound localization in 3D space relies on a variety of auditory cues resulting from the encoding provided by the lower and higher regions of the auditory path. During the last 50 years different theories and models have been developed to describe psychoacoustic phenomena in sound localization inspired by the processing that is undertaken in the human auditory system. In this paper, a biologically inspired model of human sound localization is described and the encoding of the known auditory cues by the model is explored. In particular, the model takes as an input binaural and monaural stationary signals that carry information about the Interaural Time Difference (ITD), the Interaural Level Difference (ILD) and the spectral variation of the Head Related Transfer Function (HRTF). The model processes these cues through a series of linear and nonlinear units, that simulate the peripheral and the pre-processing stages of the auditory system. The encoded cues, which in the model are represented by excitation-inhibition (EI) and the time average (TA) activity patterns, are then decoded by a central processing unit to estimate the final location of the sound source