The contribution of dynamic cues to externalization of virtual source in virtual auditory display

It is well known that static virtual auditory display with headphone is inclined to create the auditory perception of in-head-localization, especially for target virtual sources in the median plane. By introducing the dynamic variation of binaural pressures caused by head turning, dynamic virtual auditory display eliminates the in-head-localization effectively. The present work investigates the contributions of dynamic interaural time difference (ITD) and dynamic interaural level difference (ILD) in binaural pressures to the externalization of auditory perception. By modifying the head-related transfer functions used in a dynamic virtual auditory display, binaural signals with dynamic ITD or dynamic ILD alone are created and presented by headphone. A psychoacoustic experiment is conducted to evaluate the extent of perceived externalization. The experiment results prove that, for the target virtual source in the median plane, dynamic ITD and dynamic ILD contribute to the externalization of low and high frequency components of the stimuli respectively. For wideband stimulus with low and high frequency components, both dynamic ITD and dynamic ILD contribute externalization but dynamic ITD contributes more than that of dynamic ILD.