Tactile maps support blind and visually impaired people in orientation and to familiarize with unfamiliar environments. Interactive approaches complement these maps with auditory feedback. However, commonly these approaches focus on blind people. We present an approach which incorporates visually impaired people by visually augmenting relevant parts of tactile maps. These audiovisual tactile maps can be used in conjunction with common tablet computers and smartphones. By integrating conductive elements into 3D printed tactile maps, they can be recognized by a single touch on the mobile device's display, which eases the handling for blind and visually impaired people. To allow multiple elevation levels in our transparent tactile maps, we conducted a study to reconcile technical and physiological requirements of off-the-shelf 3D printers, capacitive touch inputs and the human tactile sense. We propose an interaction concept for 3D printed audiovisual tactile maps, verify its feasibility and test it with a user study. Our discussion includes economic considerations crucial for a broad dissemination of tactile maps for both blind and visually impaired people.

Tactile graphics play an essential role in knowledge transfer for blind people. The tactile exploration of these graphics is often challenging because of the cognitive load caused by physiological constraints and their complexity. The coupling of physical tactile graphics with electronic devices offers to support the tactile exploration by auditory feedback. Often, these systems have strict constraints regarding their mobility or the process of coupling both components. Additionally, visually impaired people cannot appropriately benefit from their residual vision. This article presents a concept for 3D printed tactile graphics, which offers to use audio-tactile graphics with usual smartphones or tablet-computers. By using capacitive markers, the coupling of the tactile graphics with the mobile device is simplified. These tactile graphics integrating these markers can be printed in one turn by off-the-shelf 3D printers without any post-processing and allows us to use multiple elevation levels for graphical elements. Based on the developed generic concept on visually augmented audio-tactile graphics, we presented a case study for maps. A prototypical implementation was tested by a user study with visually impaired people. All the participants were able to interact with the 3D printed tactile maps using a standard tablet computer. To study the effect of visual augmentation of graphical elements, we conducted another comprehensive user study. We tested multiple types of graphics and obtained evidence that visual augmentation may offer clear advantages for the exploration of tactile graphics. Even participants with a minor residual vision could solve the tasks with visual augmentation more quickly and accurately.