UbiBraille: designing and evaluating a vibrotactile Braille-reading device

Blind people typically resort to audio feedback to access information on electronic devices. However, this modality is not always an appropriate form of output. Novel approaches that allow for private and inconspicuous interaction are paramount. In this paper, we present a vibrotactile reading device that leverages the users' Braille knowledge to read textual information. UbiBraille consists of six vibrotactile actuators that are used to code a Braille cell and communicate single characters. The device is able to simultaneously actuate the users' index, middle, and ring fingers of both hands, providing fast and mnemonic output. We conducted two user studies on UbiBraille to assess both character and word reading performance. Character recognition rates ranged from 54% to 100% and were highly character- and user-dependent. Indeed, participants with greater expertise in Braille reading/writing were able to take advantage of this knowledge and achieve higher accuracy rates. Regarding word reading performance, we investigated four different vibrotactile timing conditions. Participants were able to read entire words and obtained recognition rates up to 93% with the most proficient ones being able achieve a rate of 1 character per second.