Localisation cues and features of the head-related transfer functions

Humans localize sound based on the sound signals at the two ears. The properties of the sound transmission from the sound source to the listener's eardrums - described by head-related transfer functions (HRTFs) - enable the listener to determine the direction of the sound. It has long been known that the perceived direction to the sound source, to a large extent, is influenced by the time difference between the two ears. Yet it is still unknown exactly which other features in HRTFs that are responsible for localization. It is for example unexplained, how a listener can perceive the elevation of a sound source with an unknown signal and placed in the median plane. Furthermore, the mechanism, which gives an out-of-head localization for real binaural signals but an in-the-head localization for other signals with level and time differences in the same order of magnitude at the two ears, is still not understood. The project attempts to contribute in the understanding of these matters. Supported by STVF/FTP.