Directional-band-dominant spectral region for the sound localisation in the median plane

Previous studies have reported that the direction of a band-limited sound stimulus in the median plane is localised based on its centre frequency instead of its actual location. The frequency band that determines this localisation is referred to as the directional-band. However, since most relevant studies employed a coarse localisation response scale or a limited range of frequency bands, the precise localisation sensitivity of each frequency band over the whole audible range is not yet clearly established. Therefore, this paper employed a comprehensive approach to the localisation of band-limited stimuli, utilising a continuous response scale within the whole median plane circle and consecutive 1/3-octave frequency bands within 100Hz-16kHz in the listening test. The results show that the `directional-bands' fall exclusively within the spectral region between 2.5kHz and 8kHz. Moreover, a `pitch-height effect' is observed within this spectral region, correlating to the elevation range of around 20 to 90. Although previous studies find directional-bands dispersed over a wide frequency range, not limited to a particular region, the responses in the directional-band-dominant spectral region from this study were statistically distinct against the other spectral regions for all subjects and source directions.