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Sonification is a promising way for blind and visually impaired people to capture and process information purely auditory, e.g., by mapping distance metrics on sound characteristics. To optimally use the users' sensory bandwidth and cognitive load a sequential scanning at multiple azimuth angles instead of only one measuring point straight ahead could be a suitable option. Thus, we present a preliminary cross-platform implementation and evaluation of such a sequential 'line-scanning sonification' using off-the-shelf components while comparing frequency (FM) and amplitude modulation (AM). In our user study with blindfolded and visually impaired participants, users gained a more accurate mental model in significantly shorter time by means of FM compared to AM and the HoloLens' usability was rated better than our LIDAR prototype's. These initial findings show possibilities for further improvement, so that similar approaches could be used more and better in blind and visually impaired peoples' everyday life.

Virtual Reality (VR) promises expanded access to spatial information, especially for blind and visually impaired people. Through haptic and acoustic feedback, real world's limitations like the risk of injury or the necessity of a sighted safety assistant can be circumvented. However, the best possible profit of this technology requires interactive locomotion in large virtual environments to overcome real world space limitations. Thus, we present formative insights of blind people's egocentric VR locomotion by comparing four different implementations (i.e., two VR treadmills, trackers on the ankles or joystick based locomotion) in a qualitative and quantitative user study with seven blind and visually impaired participants. Our results reveal novel insights on characteristics of each implementation in terms of usability and practicability and also provide recommendations for further work in this field with the target user group in sight.

When thinking of Virtual Reality (VR), most people think of stunning audio-visual environments in the context of entertainment. However, VR can also provide haptic information, e.g., to convey spatial information to blind and visually impaired people. In this context of accessibility they might be able to explore independently and self-determined tactile graphics, e.g., the structure of unknown real places prior to visiting them. Thus, we propose and evaluate tabletop virtual objects that can be felt by nowadays commercially available VR components, instead of exploring physical models (e.g., 3D printed maps) with the bare hand. These can be easily placed on an empty table, giving the blind user faster and more independent access to tactile information than with real physical representations. Our comprehensive pilot user study shows that it is possible to recognize floor plans and simple geometric shapes in this context. Also, the insights gained with regard to the suitability for practical application in this context point out the way to eased access to spatial (virtual) information using off-the-shelf components which can significantly support blind and visually impaired users' autonomy.

As urbanization progresses, cities are becoming increasingly complex. To make this complexity advantageous, Smart Cities integrate intelligent sensors that communicate with each other and are invisible to citizens, so that they can offer additional services. Despite the fact that the inclusion of diverse citizens is an essential requirement of Smart Cities, Ambient Intelligence is often not considered under accessibility aspects. The central question in this context is how disadvantaged groups in particular can benefit from Smart Cities. It is extremely important for people with disabilities to be able to move autonomously in public spaces. For this purpose, however, people who are blind sometimes need to be able to ask other people for directions. Knowing whether people are present can be important information. In our exemplary case study, Ambient Intelligence is used for people with visual impairments, so that they can decide whether they want to go to this or an alternative place based on the information about the density of people in a place.

3D models are an important means for understanding spatial contexts. Today these models can be materialized by 3D printing, which is increasingly used at schools for people with visual impairments. In contrast to sighted people, people with visual impairments have so far, however, neither been able to search nor to print 3D models without assistance. This article describes our work to develop an aid for people with visual impairments that would facilitate autonomous searching for and printing of 3D models. In our initial study, we determined the requirements to accomplish this task by means of a questionnaire and developed a first approach that allowed personal computer-based 3D printing. An extended approach allowed searching and printing using common smartphones. In our architecture, technical details of 3D printers are abstracted by a separate component that can be accessed via Wi-Fi independently of the actual 3D printer used. It comprises a search of the models in an annotated database and 3D model retrieval from the internet. The whole process can be controlled by voice interaction. The feasibility of autonomous 3D printing for people with visual impairments is shown with a first user study. Our second user study examines the usability of the user interface when searching for 3D models on the internet and preparing them for the materialization. The participants were able to define important printing settings, whereas other printing parameters could be determined algorithmically.

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.

Neben herkommlichen taktilen Drucktechniken fur blinde Menschen findet auch der 3D-Druck zunehmend Verbreitung. Wahrend anfangliche Ansatze beabsichtigten, mit dieser alternativen Drucktechnologie qualitativ ahnliche Druckresultate zu erzielen, nutzen neuere Ansatze deren Potenzial, um interaktive Drucke zu erstellen. Ausgehend von dieser Entwicklung verschafft dieser Artikel einen Uberblick uber wesentliche Ansatze fur die Erstellung von vielfaltigen taktilen Materialen mittels 3D-Druckern. Er zeigt dabei insbesondere den Wandel von statischen zu interaktiven Ansatzen auf. Dabei muss bei Letzteren eine Kopplung zwischen den taktilen 3D-Drucken und elektronischen Entitaten erfolgen, welche durch unterschiedliche Sensorik umgesetzt werden kann. Zukunftige Entwicklungen konnten es erlauben, die Interaktion des Benutzers mit der kompletten Oberflache von 3D-Drucken sensorisch zu erfassen und somit komplexe neue Interaktionsmoglichkeiten zu erschliesen, welche blinden wie auch sehenden Menschen hilfreich sein konnen.

Tactile materials play a major role in making information available to blind people and support their understanding for spatial matters. Due to the complex manual manufacturing process there is still a lack of suitable models for the visually impaired. Millions of 3D models are currently available on the internet and can be searched by dedicated retrieval sites. Most of them can be printed by 3D printers; however, this often isn't a trivial task even for sighted users. Blind peoples' self-dependence could be drastically increased if they were able to autonomously print 3D models at home. This paper analyses the individual tasks to actually print 3D models and adapts them to steps accessible for blind people. We introduce a workflow for the combined use of 3D printing software and consumer hardware. We verified our approach by a formal user study with visually impaired people which showed its feasibility.

Tactile maps may contribute to the orientation of blind people or alternatively be used for navigation. In the past, the generation of these maps was a manual task which considerably limited their availability. Nowadays, similar to visual maps, tactile maps can also be generated semi-automatically by tools and web services. The existing approaches enable users to generate maps by entering a specific address or point of interest. This can in principle be done by a blind user. However, these approaches actually show an image of the map on the users display which cannot be read by screen readers. Consequently, the blind user does not know what is on the map before it is printed. Ideally, the map selection process should give the user more information and freedom to select the desired excerpt. This paper introduces a novel web service for blind people to interactively select and automatically generate tactile maps. It adapts the interaction concept for map selection to the requirements of blind users whilst supporting multiple printing technologies. The integrated audio review of the map’s contents allows earlier feedback to review if the currently selected map extract corresponds to the desired information need. Changes can be initiated before the map is printed which, especially for 3D printing, saves much time. The user is able to select map features to be included in the tactile map. Furthermore, the map rendering can be adapted to different zoom levels and supports multiple printing technologies. Finally, an evaluation with blind users was used to refine our approach.

Electronic markers can be used to link physical representations and virtual content for tangible interaction, such as visual markers commonly used for tabletops. Another possibility is to leverage capacitive touch inputs of smartphones, tablets and notebooks. However, existing approaches either do not couple physical and virtual representations or require significant post-processing. This paper presents and evaluates a novel approach using a coding scheme for the automatic identification of tangibles by touch inputs when they are touched and shifted. The codes can be generated automatically and integrated into a great variety of existing 3D models from the internet. The resulting models can then be printed completely in one cycle by off-the-shelf 3D printers; post processing is not needed. Besides the identification, the object's position and orientation can be tracked by touch devices. Our evaluation examined multiple variables and showed that the CapCodes can be integrated into existing 3D models and the approach could also be applied to untouched use for larger tangibles.

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.

Nowadays, 3D models can be downloaded from the internet and increasingly be printed by low cost 3D printers. In the future, blind people could benefit from this tendency. Unfortunately, many of these models are rather complex and not appropriate for the purely tactile exploration. To obtain quantitative data about how 3D printable models for blind people should be constructed, the tactile exploration can be recorded by video. However, the analysis of these videos is quite time consuming and expensive. Additionally, inaccuracies and masking effects may impede the use of this technique. In this paper we introduce a novel approach to automatically equip existing 3D models with a mesh of conductive wires which enable a touch sensitive surface for the printed 3D objects. These touch sensing 3D models can be printed in one turn by off-the-shelf 3D printers and used as an alternative to video recording. It allows exact registration of when and where the 3D object has been touched. In our multi-touch solution, particular attention has been paid to limit the number of necessary wires between 3D object and sensing electronics. Finally, our approach is evaluated by a feasibility study.

Haptic feedback may support immersion and presence in virtual reality (VR) environments. The emerging market of consumer devices offers first devices which are expected to increase the degree of feeling being actually present in a virtual environment. In this paper we introduce a novel evaluation that examines the influence of different types of haptic feedback on presence and performance regarding manual tasks in VR. Therefore, we conducted a comprehensive user study involving 14 subjects, who performed throwing, stacking and object identification tasks in VR with visual (i.e., sensory substitution), vibrotactile or force feedback. We measured the degree of presence and task-related performance metrics. Our results indicate that regarding presence vibrotactile feedback outperforms haptic feedback which performs better than visual feedback only. In addition, force feedback significantly lowered the execution time for the throwing and the stacking task. In object identification tasks, the vibrotactile feedback increased the detection rates compared to the vibrotactile and force feedback, but also increased the required time of identification. Despite the inadequacies of the still young consumer technology, there were nevertheless strong indications of connections between presence, task fulfillment and the type of haptic feedback.

The interest in virtual and augmented reality increased rapidly in the last years. Recently, haptic interaction and its applications get into focus. In this paper, we suggest the exploration of virtual objects using off-the-shelf VR game controllers. These are held like a pen with both hands and were used to palpate and identify the virtual object. Our study largely coincides with comparable previous work and shows that a ready-to-use VR system can be basically used for haptic exploration. The results indicate that virtual objects are more effectively recognized with closed eyes than with open eyes. In both cases, objects with a bigger morphological difference were identified the most frequently. The limitations due to quality and quantity of tactile feedback should be tackled in future studies that utilize currently developed wearable haptic devices and haptic rendering involving all fingers or even both hands. Thus, objects could be identifiable more intuitively and haptic feedback devices for interacting with virtual objects will be further disseminated.

Although most readers associate the term virtual reality (VR) with visually appealing entertainment content, this technology also promises to be helpful to disadvantaged people like blind or visually impaired people. While overcoming physical objects’ and spaces’ limitations, virtual objects and environments that can be spatially explored have a particular benefit. To give readers a complete, clear and concise overview of current and past publications on touchable and walkable audio supplemented VR applications for blind and visually impaired users, this survey paper presents a high-level taxonomy to cluster the work done up to now from the perspective of technology, interaction and application. In this respect, we introduced a classification into small-, medium- and large-scale virtual environments to cluster and characterize related work. Our comprehensive table shows that especially grounded force feedback devices for haptic feedback (‘small scale’) were strongly researched in different applications scenarios and mainly from an exocentric perspective, but there are also increasingly physically (‘medium scale’) or avatar-walkable (‘large scale’) egocentric audio-haptic virtual environments. In this respect, novel and widespread interfaces such as smartphones or nowadays consumer grade VR components represent a promising potential for further improvements. Our survey paper provides a database on related work to foster the creation process of new ideas and approaches for both technical and methodological aspects.

Virtual reality is currently experiencing a comeback. A considerable market has developed for VR computer games and educational applications. Some solutions integrate tracked devices which allow users to freely move within a certain space. Virtual 3D model can be visually explored, implemented collision detected allows users to get a feedback for instance by sound or vibration. For research projects there are several approaches which offer to get the actual feedback for the fingers of a hand, when the users virtually touches the surface of a 3D model. However, in the consumer market currently no product is sold which offers this direct feedback for the whole hand. In this paper we introduce a low-cost hand exoskeleton which is usable in conjunction with commodity hardware. It covers each of the five fingers of the user's hand, its design is open-source, low-cost, can be customized and 3D printed by individuals. It aims at improving the haptic perception of users, bases of a popular physical computing platform and is designed to be assembled even by electronically unexperienced users. We show the integration of our lean interface of the wireless exoskeleton into exemplary VR environment and describe a calibration process which is flexible for customizations.