This paper introduces Shape2Vibe, a co-design tool for collaboratively designing vibrotactile feedback with people with deafblindness. We outline how a first version of Shape2Vibe was developed and tested. We explain to what extent the tool supports communication during the design process and how it can be used to design meaningful vibrotactile feedback for any given situation. The results from a co-design evaluation study indicate that Shape2Vibe sufficiently supports communication in a co-design session to enable co-design between a designer and people with deafblindness.

Many devices, such as smart phones, implement vibration motors for tactile feedback. When multiple vibration motors are placed on, for instance, the backrest of a chair it is possible to trace shapes on the back of a person by sequentially switching motors on and off. Social Haptic Communication (SHC) is a tactile mode of communication for persons with deafblindness that makes use of tracing shapes or other types of spatiotemporal patterns with the hand on the back of another person. This could be emulated using vibrotactile patterns. Here we investigated whether SHC users with deafblindness would recognize the vibrotactile patterns as SHC signs (Haptices). In several cases the participants immediately linked a vibrotactile patterns to the Haptice that is was meant to imitate. Together with the participants we improved and expanded the set of vibrotactile patterns.

Social Haptic Communication (SHC) is one of the many tactile modes of communication used by persons with deafblindness to access information about their surroundings. SHC usually involves an interpreter executing finger and hand signs on the back of a person with multi-sensory disabilities. Learning SHC, however, can become challenging and time-consuming, particularly to those who experience deafblindness later in life. In this work, we present PatRec: a mobile game for learning SHC concepts. PatRec is a multiple-choice quiz game connected to a chair interface that contains a 3x3 array of vibration motors emulating different SHC signs. Players collect scores and badges whenever they guess the right SHC vibration pattern, leading to continuous engagement and a better position on a leaderboard. The game is also meant for family members to learn SHC. We report the technical implementation of PatRec and the findings from a user evaluation.

Vibrotactile Morse code provides a way to convey words using the sense of touch with vibrations. This can be useful in applications for users with a visual and/or auditory impairment. The advantage of using vibrotactile Morse code is that it is technically easy to accomplish. The usefulness of tactile Morse code also depends on how easy it is to learn to use without providing a visual representation of the code. Here we investigated learning of the vibrotactile the Morse code alphabet without any visual representation of the code and whether the learned letters can immediately be used to recognize words. Two vibration motors were used: one was attached to the left arm (dots) and the other to the right arm (dashes). We gave the participants a learning session of 30 minutes and determined how many letters they had learned. All participants managed to learn at least 15 letters in this time. Directly afterward, they were presented with 2-, 3-, 4-, or 5-letter words consisting of only the letters they had learned. Participants were able to identify words, but correct rates decreased rapidly with word length. We can conclude that it is possible to learn vibrotactile Morse code using only a vibrotactile representation (15 to 24 letters in 30 minutes). After the learning session, it was possible to recognise words, but to increase the recognition rates extra training would be beneficial.

The size of an object can be perceived by pinching it between thumb and index finger. Here we show a new haptic illusion in which the length of objects with large local curvature is overestimated. Participants pinched ellipses between the thumb and the index finger and matched the size of the major axis to a set of rectangles which carry no curvature information. Ellipses with high local curvature at the contact areas were consistently rated to be larger than those with smaller curvature. This illusion shows that local shape information can influence judgment the size of an object.