Visually Augmented Audio-Tactile Graphics for Visually Impaired People

Abstract

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.

Tactile cartography in the digital age: A review and research agenda

“…Holloway et al (2018) conjecture that 3D printed maps reduce the cognitive load for map users by reducing the need for graphical tools that help illustrate an abstracted 2D landscape -such as side views or occlusion -allowing for a more 'purely' tactile experience; however, they note that it is unclear as to whether these benefits extend to maps specifically. 3D-printed touchplates that attach to tablet computers have been a popular research topic (Götzelmann, 2018;O'Modhrain et al, 2015), but the user experience has not been uniformly positive. Kane et al (2013) observed that users in their study were reluctant to learn how to operate a new device, although the users noted that it may be useful as a training device for people who have recently become B/ VI.…”

“…That said, reading a tactile map is a much more cognitively intensive task than reading a visual map due to the need for constant referencing and orientation via touch (Ducasse et al, 2018;Perdue and Lobben, 2016), a task made even more difficult by the lack of a standardized symbol set. Digital tactile maps do have the capacity to reduce cognitive load by incorporating highfidelity media such as audio information (Bardot et al, 2016;Götzelmann, 2018), reducing the need to memorize symbols and labels, and so on. Digital tactile maps can also encourage exploration (Zeng and Weber, 2016) and facilitate learning to create further tactile media (Rassmus-Gröhn et al, 2007).…”

Educational Integration of People With Vision Impairments

“…These audiovisual tactile maps can be used in conjunction with tablets and smart phones. By integrating conductive elements into tactile maps printed in 3D, they can be recognized with a single touch on the screen of a mobile device, which facilitates the management of blind and partially sighted people 37 . Schools for the blind suffer from marginalization in terms of easy access and use of communication and assistive technology 38 .…”

"If you've gone straight, now, you must turn left" - Exploring the use of a tangible interface in a collaborative treasure hunt for people with visual impairments

“…Because touch and tactile (passive) interfaces are largely used by educators for VI students [28], research on TUIs for people with VIs has investigated different curricular fields. Tangible interfaces have been developed and evaluated to assist the exploration of diagrams [22], graphics [33], mathematics [2] and maps [6,20]. For instance, Ducasse and colleagues [17,18] developed a TUI to help people with VIs explore zoomable geographical maps.…”