HapticHead - Around-the-head tactile display

HapticHead is a novel around-the-head tactile display which can be used in a variety of applications such as guidance utilizing moving tactile cues, important tactile notifications or immersive Virtual- and Augmented Reality experiences.

One of the most interesting use cases and current research directions is aiding visually impaired individuals mostly in micro- but also in macro-navigation.

Developed by the Human-Computer Interaction group at the University of Hannover, HapticHead is under active development and evaluation as of 2020.

Guidance

HapticHead can generate moving tactile cues which allow intuitive spatial awareness of nearby virtual or real objects, positions or orientations. This also allows navigating visually impaired people which is an active topic of research.

Immersion

Applications in Virtual- and Augmented Reality aim to immerse the user in a fully-fletched experience in which a HapticHead display can play a major role in by letting the user feel virtual snowflakes, shockwaves or objects close to their head.

Notifications

Getting a directional tactile notification directly on the surface of the head in the event of emergency may help save precious time. This kind of notification cannot be missed and is interpreted intuitively, giving the user just that little bit of extra time to react.

2020
Design and Evaluation of On-the-Head Spatial Tactile Patterns Oliver Beren Kaul, Michael Rohs, Marc Mogalle 19th International Conference on Mobile and Ubiquitous Multimedia - MUM '20
Full Paper
        
We propose around-the-head spatial vibrotactile patterns for representing different kinds of notifications. The patterns are defined in terms of stimulus location, intensity profile, rhythm, and roughness modulation. A first study evaluates recall and distinguishability of 30 patterns, as well as agreement on meaning without a predetermined context: Agreement is low, yet the recognition rate is surprisingly high. We identify which kinds of patterns users recognize well and which ones they prefer. Static stimulus location patterns have a higher recognition rate than dynamic patterns, which move across the head as they play. Participants preferred dynamic patterns for comfort. A second study shows that participants are able to distinguish substantially more around-the-head spatial patterns than smartphone-based patterns. Spatial location has the highest positive impact on accuracy among the examined features, so this parameter allows for a large number of levels.
Vibrotactile Funneling Illusion and Localization Performance on the Head Oliver Beren Kaul, Michael Rohs, Benjamin Simon, Kerem Can Demir, Kamillo Ferry Proceedings of the 2020 CHI Conference on Human Factors in Computing Systems
Full Paper
        
The vibrotactile funneling illusion is the sensation of a single (non-existing) stimulus somewhere in-between the actual stimulus locations. Its occurrence depends upon body location, distance between the actuators, signal synchronization, and intensity. Related work has shown that the funneling illusion may occur on the forehead. We were able to reproduce these findings and explored five further regions to get a more complete picture of the occurrence of the funneling illusion on the head. The results of our study (24 participants) show that the actuator distance, for which the funneling illusion occurs, strongly depends upon the head region. Moreover, we evaluated the centralizing bias (smaller perceived than actual actuator distances) for different head regions, which also showed widely varying characteristics. We computed a detailed heat map of vibrotactile localization accuracies on the head. The results inform the design of future tactile head-mounted displays that aim to support the funneling illusion.
2019
3DTactileDraw: A Tactile Pattern Design Interface for Complex Arrangements of Actuators Oliver Beren Kaul, Leonard Hansing, Michael Rohs Extended Abstracts of the 2019 CHI Conference on Human Factors in Computing Systems
Poster
        
Creating tactile patterns for a grid or a 3D arrangement of a large number of actuators presents a challenge as the design space is huge. This paper explores two different possibilities of implementing an easy-to-use interface for tactile pattern design on a large number of actuators around the head. Two user studies were conducted in order to iteratively improve the prototype to fit user needs.
Concept for Navigating the Visually Impaired using a Tactile Interface around the Head Oliver Beren Kaul, Michael Rohs Hacking Blind Navigation Workshop at CHI '19
Workshop Paper
     
2018
Requirements of Navigation Support Systems for People with Visual Impairments Oliver Beren Kaul, Michael Rohs Proceedings of the 2018 ACM International Joint Conference and 2018 International Symposium on Pervasive and Ubiquitous Computing and Wearable Computers
Workshop Paper
        
2017
HapticHead: A Spherical Vibrotactile Grid around the Head for 3D Guidance in Virtual and Augmented Reality Oliver Beren Kaul, Michael Rohs Proceedings of the 2017 CHI Conference on Human Factors in Computing Systems - CHI '17
Full Paper
        
Current virtual and augmented reality head-mounted displays usually include no or only a single vibration motor for haptic feedback and do not use it for guidance. We present HapticHead, a system utilizing multiple vibrotactile actuators distributed in three concentric ellipses around the head for intuitive haptic guidance through moving tactile cues. We conducted three experiments, which indicate that HapticHead vibrotactile feedback is both faster (2.6 s vs. 6.9 s) and more precise (96.4{%} vs. 54.2{%} success rate) than spatial audio (generic head-related transfer function) for finding visible virtual objects in 3D space around the user. The baseline of visual feedback is as expected more precise (99.7{%} success rate) and faster (1.3 s) in comparison, but there are many applications in which visual feedback is not desirable or available due to lighting conditions, visual overload, or visual impairments. Mean final precision with HapticHead feedback on invisible targets is 2.3° compared to 0.8° with visual feedback. We successfully navigated blindfolded users to real household items at different heights using HapticHead vibrotactile feedback independently of a head-mounted display.
Increasing Presence in Virtual Reality with a Vibrotactile Grid Around the Head Oliver Beren Kaul, Kevin Meier, Michael Rohs Human-Computer Interaction -- INTERACT 2017: 16th IFIP TC 13 International Conference, Mumbai, India, September 25-29, 2017, Proceedings, Part IV
Short Paper
        
A high level of presence is an important aspect of immersive virtual reality applications. However, presence is difficult to achieve as it depends on the individual user, immersion capabilities of the system (visual, auditory, and tactile) and the concrete application. We use a vibrotactile grid around the head in order to further increase the level of presence users feel in virtual reality scenes. In a between-groups comparison study the vibrotactile group scored significantly higher in a standardized presence questionnaire compared to the baseline of no tactile feedback. This suggests the proposed prototype as an additional tool to increase the level of presence users feel in virtual reality scenes.
2016
HapticHead: 3D Guidance and Target Acquisition through a Vibrotactile Grid Oliver Beren Kaul, Michael Rohs Proceedings of the 2016 CHI Conference Extended Abstracts on Human Factors in Computing Systems
Poster
        
Current generation virtual reality (VR) and augmented reality (AR) head-mounted displays (HMDs) usually include no or only a single vibration motor for haptic feedback and do not use it for guidance. We present HapticHead, a system utilizing 20 vibration motors distributed in three concentric ellipses around the head to give intuitive haptic guidance hints and to increase immersion for VR and AR applications. Our user study indicates that HapticHead is both faster (mean=3.7s, SD=2.3s vs. mean=7.8s, SD=5.0s) and more precise (92.7{%} vs. 44.9{%} hit rate) than auditory feedback for the purpose of finding virtual objects in 3D space around the user. The baseline of visual feedback is as expected more precise (99.9{%} hit rate) and faster (mean=1.5s, SD=0.6s) in comparison but there are many applications in which visual feedback is not desirable or available due to lighting conditions, visual overload, or visual impairments.
Wearable Head-mounted 3D Tactile Display Application Scenarios Oliver Beren Kaul, Michael Rohs Proceedings of the 18th International Conference on Human-Computer Interaction with Mobile Devices and Services Adjunct
Workshop Paper
        

HapticHead is developed by the Human-Computer Interaction Group at the University of Hannover. For additional details see our papers, available in the publications section.

For inquiries, please contact Oliver Beren Kaul - kaul@hci.uni-hannover.de.