Discriminating Between Intensities and Velocities of Mid-Air Haptic Patterns

Abstract

This study investigates people's ability in discriminating between different intensities and velocities of mid-air haptic (MAH) sensations. Apart from estimating the just noticeable differences (JND), we also investigated the impact of age on discrimination performance, and the relationship between someone's confidence in his/her performance and the actual discrimination performance. In an experimental setup , involving 50 participants, we obtained a JND of 12.12% for intensities and 0.51 rev/s for velocities. Surprisingly, the impact of age on discrimination performance was only small and almost negligible. Furthermore, participants' subjective perception of their discrimination performance aligned well with their actual discrimination performance. These results are encouraging for the use of intensities and velocities as dimensions in the design of MAH patterns to convey information to the user.

Designing Distinguishable Mid-Air Ultrasound Tactons with Temporal Parameters

“…They found that the static focal point with 200 Hz AM frequency showed a higher amplitude detection threshold of 556.9 Pa compared to the 334.1 Pa detection threshold by the STM moving the focal point along a line path. Regarding discrimination thresholds or just noticeable differences, prior research has investigated the JND for the STM drawing frequency [48,68]. Wojna et al showed an average JND of 20.7% for five reference drawing frequencies ranging from 30 Hz to 70 Hz [68].…”

“…Wojna et al showed an average JND of 20.7% for five reference drawing frequencies ranging from 30 Hz to 70 Hz [68]. Also, for six reference drawing frequencies ranging from 1 Hz to 2 Hz with the step size of 0.2 Hz, the average JND was 25.5% when the moving focal point vibrated at a 125 Hz AM frequency [48]. Our work complements this literature by contributing data on the JND for AM frequency as another temporal parameter for mid-air ultrasound haptic design.…”

DOLPHIN: A Framework for the Design and Perceptual Evaluation of Ultrasound Mid-Air Haptic Stimuli

“…Hoshi et al [Hoshi et al 2009b[Hoshi et al , 2010 studied the identification and discrimination of movement directions for linear, circular, spiral, and random AM focal point motions. Using Ultraleap's Sensation Editor, Rutten et al assessed the identification of both static and dynamic AM focal point [Rutten et al 2019], and later the discrimination between intensities and velocities of dynamic AM mid-air haptic patterns [Rutten et al 2020].…”

“…To the best of our knowledge, all psychophysics studies involving mid-air haptic stimuli have used either custom stimuli written "from scratch" or they have restricted themselves to the use of a limited set of standard stimuli available thanks to, e.g., commercial stimulus generation tools such as the Ultraleap Sensation Editor (e.g. [Rutten et al 2020[Rutten et al , 2019). All of these works could have benefited from a framework to facilitate design and later reuse of stimuli.…”

Perception of Ultrasound Haptic Focal Point Motion

“…They investigated the perception of circles created by a rapidly moving focal point, finding a relationship between circle size, movement speed, and perceived intensity. Rutten et al [33] investigated the just-noticeable difference (JND) for output intensity and focal point velocity when rendering haptic patterns. They found JNDs of 12.1% and 0.51 rev s -1 , respectively.…”