Localization in a Head-Related Transfer Function-based virtual audio synthesis using additional high-pass and low-pass filtering of sound sources

Abstract

Listening tests were carried out for investigating the localization judgments of untrained subjects through equalized headphones and with HRTF synthesis. The investigation was made on the basis of the former ‘Graphical User Interface for Blind Persons’ project in order to determine the possibilities of a 2D virtual sound screen and headphone playback. 50 untrained subjects evaluated a virtual audio display in front of the listener using different horizontal and vertical resolutions on a 2D surface. A listening test using white and filtered noise signals was followed by a special investigation using simple high-pass and low-pass filtering of the original sound in order to increase correct vertical localization judgments. The simulation uses high-pass filtering for higher elevations and low-pass filtering for lower elevations in a 5×2 and a 3×3 spatial resolution. Results of the listening test will be presented and the efficiency of the filtering in correct localization judgments will be discussed.