Importance of ITD and spectral cues for localization in the horizontal plane

When localizing spatial sound, our hearing makes use of certain characteristics of the sound usually called localization cues. The cues can be divided into two categories; one consisting of characteristics related to the timing and one based on spectral features. The timing cue is called the ITD and describes the difference in arrival time at the two ears. The spectral features give both monaural and interaural cues to the localization and are based on the directional filtering of the head, torso and especially the pinna of the listener. This work was done to reveal the importance of the two types of cues in the horizontal plane, and especially the robustness of the ITD as the leading cue has been of interest. The investigation was done through a series of listening experiments, where the two types of cues were extracted from HRTFs, manipulated independently and combined in new "artificial" HRTFs. The new set of HRTFs consisted of a large variety of combinations of cues ranging from combinations where the two cues supported each other to combinations where the two cues were highly conflicting. Supported by STVF.