SoundBar: exploiting multiple views in multimodal graph browsing

In this paper we discuss why access to mathematical graphs is problematic for visually impaired people. By a review of graph understanding theory and interviews with visually impaired users, we explain why current non-visual representations are unlikely to provide effective access to graphs. We propose the use of multiple views of the graph, each providing quick access to specific information as a way to improve graph usability. We then introduce a specific multiple view system to improve access to bar graphs called SoundBar which provides an additional quick audio overview of the graph. An evaluation of SoundBar revealed that additional views significantly increased accuracy and reduced time taken in a question answering task

Feeling what you hear: tactile feedback for navigation of audio graphs

Access to digitally stored numerical data is currently very limited for sight impaired people. Graphs and visualizations are often used to analyze relationships between numerical data, but the current methods of accessing them are highly visually mediated. Representing data using audio feedback is a common method of making data more accessible, but methods of navigating and accessing the data are often serial in nature and laborious. Tactile or haptic displays could be used to provide additional feedback to support a point-and-click type interaction for the visually impaired. A requirements capture conducted with sight impaired computer users produced a review of current accessibility technologies, and guidelines were extracted for using tactile feedback to aid navigation. The results of a qualitative evaluation with a prototype interface are also presented. Providing an absolute position input device and tactile feedback allowed the users to explore the graph using tactile and proprioceptive cues in a manner analogous to point-and-click techniques

MultiVis: improving access to visualisations for visually impaired people

This paper illustrates work undertaken on the MultiVis project to allow visually impaired users both to construct and browse mathematical graphs effectively. We start by discussing the need for such work, before discussing some of the problems of current technology. We then discuss Graph Builder, a novel tool to allow interactive graph construction, and Sound Bar which provides quick overview access to bar graphs

Tac-tiles: multimodal pie charts for visually impaired users

Tac-tiles is an accessible interface that allows visually impaired users to browse graphical information using tactile and audio feedback. The system uses a graphics tablet which is augmented with a tangible overlay tile to guide user exploration. Dynamic feedback is provided by a tactile pin-array at the fingertips, and through speech/non-speech audio cues. In designing the system, we seek to preserve the affordances and metaphors of traditional, low-tech teaching media for the blind, and combine this with the benefits of a digital representation. Traditional tangible media allow rapid, non-sequential access to data, promote easy and unambiguous access to resources such as axes and gridlines, allow the use of external memory, and preserve visual conventions, thus promoting collaboration with sighted colleagues. A prototype system was evaluated with visually impaired users, and recommendations for multimodal design were derived

Web-based multimodal graphs for visually impaired people

This paper describes the development and evaluation of Web-based multimodal graphs designed for visually impaired and blind people. The information in the graphs is conveyed to visually impaired people through haptic and audio channels. The motivation of this work is to address problems faced by visually impaired people in accessing graphical information on the Internet, particularly the common types of graphs for data visualization. In our work, line graphs, bar charts and pie charts are accessible through a force feedback device, the Logitech WingMan Force Feedback Mouse. Pre-recorded sound files are used to represent graph contents to users. In order to test the usability of the developed Web graphs, an evaluation was conducted with bar charts as the experimental platform. The results showed that the participants could successfully use the haptic and audio features to extract information from the Web graphs

Constructing sonified haptic line graphs for the blind student: first steps

Line graphs stand as an established information visualisation and analysis technique taught at various levels of difficulty according to standard Mathematics curricula. It has been argued that blind individuals cannot use line graphs as a visualisation and analytic tool because they currently primarily exist in the visual medium. The research described in this paper aims at making line graphs accessible to blind students through auditory and haptic media. We describe (1) our design space for representing line graphs, (2) the technology we use to develop our prototypes and (3) the insights from our preliminary work

Comparing two haptic interfaces for multimodal graph rendering

This paper describes the evaluation of two multimodal interfaces designed to provide visually impaired people with access to various types of graphs. The interfaces consist of audio and haptics which is rendered on commercially available force feedback devices. This study compares the usability of two force feedback devices: the SensAble PHANToM and the Logitech WingMan force feedback mouse in representing graphical data. The type of graph used in the experiment is the bar chart under two experimental conditions: single mode and multimodal. The results show that PHANToM provides better performance in the haptic only condition. However, no significant difference has been found between the two devices in the multimodal condition. This has confirmed the advantages of using multimodal approach in our research and that low-cost haptic devices can be successful. This paper introduces our evaluation approach and discusses the findings of the experiment

A generic approach for augmenting tactile diagrams with spatial non-speech sounds

Blind or visually impaired users typically access diagrams in the tactile medium. This paper describes TouchMelody, a system designed for augmenting such existing diagrams with 3D spatial auditory information to increase their usefulness, information content and reduce tactile clutter. The motivation for this system, an overview of its development and early experiences are presented. The two major technologies used are the Polhemus FASTRAK and the LakeDSP CP4 to facilitate the creation of a directly manipulated dynamic 3D spatial soundscape