Disparity in horizontal correspondence of sound and source positioning: The impact on spatial presence for cinematic VR

摘要

This study examines the extent to which azimuth disparity between sound-cue and image-target can be varied in cinematic virtual reality (VR), before spatial presence is broken. Exploring conscious self-reporting and autonomic arousal via galvanic skin response, it varies displacement of sound source along the horizontal plane, in five otherwise identical sound-image events, for stimuli of human and object types. The displacements are applied either consistently (at 5°, 10° or 15° offset to image) or inconsistently (two orders of randomness using 5°, 10° and 15° offsets) at uniform distance from the user/ camera position. It hypothesizes that consistently applied disparity in audio-visual lateral correspondence elicits higher tolerance before presence is broken. Stimuli of a bell alarm clock, and separately, a human actor, were produced and rendered for headset viewing and dynamic binaural headphone listening. Content was presented to participants under controlled conditions including familiarization trials. For both experiments the visual targets were associated with the sound cues through synchronous corresponding visual movement. Thirty-five participants were tested during 70 trials, using the BBC R&D 360TV player and BBC Spatial Sound Renderer. No support was found for the hypothesis relating consistency to presence. Consistency as a detenninant of arousal proved significant, but inversely to the expected direction. Presence ratings were high throughout conditions, and though some participants verbally discriminated precision in localization judgments, this did not impact ratings. The novice status of participants for both VR and dynamic binaural sound, could account for high ratings, despite familiarization trials. The multimodal environment of VR has many potentially confounding factors which affected the current study; ultimately, azimuth sound-image disparity did not noticeably affect novice experience. Further work in study design, and on the impact (both subjective and objective) of exposure on presence in VR is required at this time, to better analyze the perceptual correlates of its spatial sound technologies.