Comparing Vibrotactile and Skin-Stretch Haptic Feedback for Conveying Spatial Information of Virtual Objects to Blind VR Users

TL;DR

This study investigates how two haptic modalities—skin-stretch and vibrotactile feedback—can render spatial information about static and moving virtual objects to blind VR users by applying cues to the dorsal hand. Using a within-subject design with 10 blind participants and a custom three-gantry device, the authors compare the accuracy of perceiving object location and trajectories under both cues, for static directions/distances and moving paths. Results show skin-stretch consistently yields higher accuracy than vibrotactile cues, though participant preferences are mixed due to familiarity; the work also reveals potential for multi-modal or wearable integrations to further improve VR accessibility. The findings highlight practical design principles, calibration necessities, and safety considerations for deploying on-skin haptics in accessible VR systems, suggesting a path toward compact, wearable solutions that enhance spatial comprehension for blind users.

Abstract

Perceiving spatial information of a virtual object (e.g, direction, distance) is critical yet challenging for blind users seeking an immersive virtual reality (VR) experience. To facilitate VR accessibility for blind users, in this paper, we investigate the effectiveness of two types of haptic cues - vibrotactile and skin-stretch cues - in conveying the spatial information of a virtual object when applied to the dorsal side of a blind user's hand. We conducted a user study with 10 blind users to investigate how they perceive static and moving objects in VR with a custom-made haptic apparatus. Our results reveal that blind users can more accurately understand an object's location and movement when receiving skin-stretch cues, as opposed to vibrotactile cues. We discuss the pros and cons of both types of haptic cues and conclude with design recommendations for future haptic solutions for VR accessibility.

Figures (14)

• Figure 1: Haptic device setup: a) Front view of the three-axis gantry system haptic device, b) the touch probe, and c) study conducted at a participant’s home.
• Figure 2: Coordinates and resolution on the dorsum of the hand. The coordinates comprise eight directions and two distances.
• Figure 3: a) The movement of the touch probe in skin-stretch mode. b) The movement of the touch probe in vibration mode.
• Figure 4: Score criteria: A correct answer, marked in blue, receives full points. A partially correct answer, marked in yellow, receives half points. An incorrect answer, marked in white, receives no points.
• Figure 5: The distribution of paired-score differences in Task One. The differences were approximately symmetrically distributed around zero.