Enabling blind and visually impaired (BVI) people to perceive and interact with two-dimensional data is a complex challenge. Blind users cannot perceive graphical information in visual user interfaces and can only access text information linearly with assistive technologies. An emerging technology, 2D refreshable audio-tactile devices, is capable of presenting two-dimensional data to blind persons. While hardware development for this technology has advanced, user interface development has not progressed likewise. Therefore, there is a need to improve these devices’ user interfaces to enable BVI persons to access and use two-dimensional information.

To accomplish this, it is necessary to systematically explore and validate all key aspects of audio-tactile user interfaces. This can only be done with the use of blind test users, and it needs to be grounded in a challenging application domain. Public places such as train and bus stations represent such a domain since there is a massive interest in enabling blind persons to access and use public places independently. The user interface aspects include, among others, the design of widgets, dynamic audio-tactile interactions for navigation and camera-based pointing and gesture recognition mechanisms. Main topic domains are Audio Pinpoint Navigation, Audio-Tactile Line Chart Exploration, and Audio-Tactile UI for Travel Planning. The development of these follows a human-centred design approach, including contextual inquiry analysis, brainstorming sessions, quantitative questionnaires (NASA TLX and the System Usability Scale, SUS) and usability tests.

The results from this dissertation are expected to improve the foundation for the user interfaces of the emerging 2D refreshable tactile displays.