Tham khảo tài liệu 'advances in sound localization part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Using Virtual Acoustic Space to Investigate Sound Localisation 187 the elevation of virtual sound sources or whether ILDs in single frequency bands could be used as well. After Hausmann et al. 2009 Fig. 2. ITDs and azimuthal head-turn angle under normal and ruffcut conditions. A The azimuthal head-turn angles of owls in response to azimuthal stimulation x-axis with individualised HRTFs dotted data of two owls non-individualised HRTFs of a reference animal normal black three owls and to the stimuli from the reference owl after ruff removal ruffcut blue three owls . Arrows mark 140 stimulus position in the periphery where azimuthal head-turn angle decreased for stimulation with simulated ruff removal in contrast to stimulation with intact ruff individualised and reference owl normal where they approach a plateau at about 60 . Significant differences between stimulus conditions are marked with asterisks depending on the significance level p p in black individualised versus reference owl normal respectively in blue reference owl normal versus ruffcut . Each data point includes at least 96 trials unless indicated otherwise by the number of trials n . B The ITD in ps contained in the HRTFs at 0 elevation is plotted against stimulus azimuth in degree for the reference owl normal black and ruffcut blue . Note the sinusoidal course of the ITD and the smaller ITD range after ruff removal. ITDs decrease at peripheral azimuths for both intact and removed ruff. 188 Advances in Sound Localization Due to the complex variations of ILDs with both elevation and azimuth in the barn owl the influence of specific cues on elevational localisation is difficult to investigate. Furthermore as we have just seen elevational localisation is influenced by cues other than the ILD which stands in contrast to the exclusive dependence of azimuthal head-turn angle on ITDs at least in the frontal field but see Hausmann et al. 2009 for azimuthal localisation in the rear . Since ILDs are .
