视听触同步刺激的数字化盲文学习方法

盲文是视障人士获取信息,学习知识的重要媒介.然而,目前基于纸质书籍的盲文学习方法只能提供盲文点位的触觉刺激,存在不便携、不易用且内容陈旧等问题.为此,本文提出了一种视觉、听觉和触觉同步刺激的数字化盲文学习方法,能够提高视障人士的盲文学习效率.基于多感知盲文学习机,本文设计了一种多感知信息匹配算法,能够输出文字、声音和盲文点位相同内容的信息,为视障人士无障碍学习盲文提供条件.短期记忆的盲文学习效果实验表明:(1)在视觉、听觉和触觉的共同刺激下,盲文学习效率最高,即在盲文学习过程中,增加视觉刺激对于视力残余人士提升盲文学习效率有显著正向促进作用;(2)在听觉和触觉的共同刺激下,盲文学习效率并不高,即全盲人士学会盲文有一定难度,需要有较长的学习曲线;(3)仅在听觉刺激下,盲文学习效率很低,即开发语音学盲文的APP不具备实践意义.     

Contrasting usability evaluation methods with blind users

Usability tests are a part of user-centered design. Usability testing with disabled people is necessary, if they are among the potential users. Several researchers have already investigated usability methods with sighted people. However, research with blind users is insufficient, for example, due to different knowledge on the use of assistive technologies and the ability to analyze usability issues from inspection of non-visual output of assistive devices. From here, the authors aspire to extend theory and practice by investigating four usability methods involving the blind, visually impaired and sighted people. These usability methods comprise of local test, synchronous remote test, tactile paper prototyping and computer-based prototyping. In terms of effectiveness of evaluation and the experience of participants and the facilitator, local tests were compared with synchronous remote tests and tactile paper prototyping with computer-based prototyping. Through the comparison of local and synchronous remote tests, it has been found that the number of usability problems uncovered in different categories with both approaches was comparable. In terms of task completion time, there is a significant difference for blind participants, but not for the visually impaired and sighted. Most of the blind and visually impaired participants prefer the local test. As for the comparison of tactile paper prototyping and computer-based prototyping, it has been revealed that tactile paper prototyping provides a better overview of an application while the interaction with computer-based prototypes is closer to reality. Problems regarding the planning and conducting of these methods as they arise in particular with blind people were also discussed. Based on the authors’ experiences, recommendations were provided for dealing with these problems from both the technical and the organization perspectives.     

A novel multimodal interface for improving visually impaired people’s web accessibility

This paper introduces a novel interface designed to help blind and visually impaired people to explore and navigate on the Web. In contrast to traditionally used assistive tools, such as screen readers and magnifiers, the new interface employs a combination of both audio and haptic features to provide spatial and navigational information to users. The haptic features are presented via a low-cost force feedback mouse allowing blind people to interact with the Web, in a similar fashion to their sighted counterparts. The audio provides navigational and textual information through the use of non-speech sounds and synthesised speech. Interacting with the multimodal interface offers a novel experience to target users, especially to those with total blindness. A series of experiments have been conducted to ascertain the usability of the interface and compare its performance to that of a traditional screen reader. Results have shown the advantages that the new multimodal interface offers blind and visually impaired people. This includes the enhanced perception of the spatial layout of Web pages, and navigation towards elements on a page. Certain issues regarding the design of the haptic and audio features raised in the evaluation are discussed and presented in terms of recommendations for future work.     

Exploration of architectural spaces by blind people using auditory virtual reality for the construction of spatial knowledge

Navigation within a closed environment requires analysis of a variety of acoustic cues, a task that is well developed in many visually impaired individuals, and for which sighted individuals rely almost entirely on visual information. For blind people, the act of creating cognitive maps for spaces, such as home or office buildings, can be a long process, for which the individual may repeat various paths numerous times. While this action is typically performed by the individual on-site, it is of some interest to investigate at which point this task can be performed off-site, at the individual's discretion. In short, is it possible for an individual to learn an architectural environment without being physically present? If so, such a system could prove beneficial for navigation preparation in new and unknown environments. The main goal of the present research can therefore be summarized as investigating the possibilities of assisting blind individuals in learning a spatial environment configuration through the listening of audio events and their interactions with these events within a virtual reality experience. A comparison of two types of learning through auditory exploration has been performed: in situ real displacement and active navigation in a virtual architecture. The virtual navigation rendered only acoustic information. Results for two groups of five participants showed that interactive exploration of virtual acoustic room simulations can provide sufficient information for the construction of coherent spatial mental maps, although some variations were found between the two environments tested in the experiments. Furthermore, the mental representation of the virtually navigated environments preserved topological and metric properties, as was found through actual navigation.     

基于国家通用盲文标调规则的汉盲转换系统

信息时代推进盲文数字化, 关乎我国广大盲人文化素质的提高和生活水平的改善. 本文实现了一种基于国家通用盲文标调规则的汉盲转换系统, 能够快速生成海量符合国家通用盲文方案的数字化资源, 满足视障人士无障碍获取信息的需求. 此系统按通用盲文规则处理汉语文本, 将其转换为符合标调规则、简写规则的盲文结果. 测试结果表明, 此系统可以准确处理标调规则、简写规则, 可得到准确的符合国家通用盲文方案的盲文数字化结果. 声调省写覆盖率、韵母简写覆盖率和篇幅增加量均与国家通用盲文方案的理论值相当, 能够快速处理长篇语料文件, 程序执行效率高, 具有实用价值, 可以用于推广国家通用盲文, 促进我国盲文数字化无障碍建设.     

Accessible smartphones for blind users: A case study for a wayfinding system

While progress on assistive technologies have been made, some blind users still face several problems opening and using basic functionalities when interacting with touch interfaces. Sometimes, people with visual impairments may also have problems navigating autonomously, without personal assistance, especially in unknown environments. This paper presents a complete solution to manage the basic functions of a smartphone and to guide users using a wayfinding application. This way, a blind user could go to work from his home in an autonomous way using an adaptable wayfinding application on his smartphone. The wayfinding application combines text, map, auditory and tactile feedback for providing the information. Eighteen visually impaired users tested the application. Preliminary results from this study show that blind people and limited vision users can effectively use the wayfinding application without help. The evaluation also confirms the usefulness of extending the vibration feedback to convey distance information as well as directional information. The validation was successful for iOS and Android devices.     

Assisting people with visual impairments in aiming at a target on a large wall-mounted display

Large interactive displays have become ubiquitous in our everyday lives, but these displays are designed for the needs of sighted people. In this paper, we specifically address assisting people with visual impairments to aim at a target on a large wall-mounted display. We introduce a novel haptic device, which explores the use of vibrotactile feedback in blind user search strategies on a large wall-mounted display. Using mid-air gestures aided by vibrotactile feedback, we compared three target-aiming techniques: Random (baseline) and two novel techniques – Cruciform and Radial. The results of our two experiments show that visually impaired participants can find a target significantly faster with the Cruciform and Radial techniques than with the Random technique. In addition, they can retrieve information on a large display about twice as fast by augmenting speech feedback with haptic feedback in using the Radial technique. Although a large number of studies have been done on assistive interfaces for people who have visual impairments, very few studies have been done on large vertical display applications for them. In a broader sense, this work will be a stepping-stone for further research on interactive large public display technologies for users who are visually impaired.     

Ergonomic principles and map design

Ergonomic principles have seldom been applied to the design of maps for use in aviation. Maps are not usually evaluated as displays of information, and the contents of maps often do not match the needs of the user. Most maps are visually so complex that it is not immediately apparent whether standard recommendations for the coding and display of information apply to them. Methods for evaluating maps have to be devised, and comparisons made between subjective and objective measures. A series of experiments has considered the content of maps in relation to the needs of the users, and has examined new methods for presenting information on maps, with a view to increasing the efficiency of map communication.     

An empirical investigation into the difficulties experienced by visually impaired Internet users

In this paper, an empirical based study is described which has been conducted to gain a deeper understanding of the challenges faced by the visually impaired community when accessing the Web. The study, involving 30 blind and partially sighted computer users, has identified navigation strategies, perceptions of page layout and graphics using assistive devices such as screen readers. Analysis of the data has revealed that current assistive technologies impose navigational constraints and provide limited information on web page layout. Conveying additional spatial information could enhance the exploration process for visually impaired Internet users. It could also assist the process of collaboration between blind and sighted users when performing web-based tasks. The findings from the survey have informed the development of a non-visual interface, which uses the benefits of multimodal technologies to present spatial and navigational cues to the user.     

Computer access for persons who are blind or visually impaired: human factors issues

Suitably adapted computers hold considerable potential for integrating people who are blind or visually impaired into the mainstream. The principal problems that preclude the achievement of this potential are human factors issues. These issues are discussed, and the problems presented by icon-based interfaces are reviewed. An argument is offered that these issues, which ostensibly pertain to the blind or visually impaired user, are fundamental issues confronting all users. There is reason to hope that the benefits of research into the human factors issues of people with vision impairments will also extend to the sighted user.     

Interactive spatial sonification for non-visual exploration of virtual maps

This paper presents a multimodal interactive system for non-visual (auditory-haptic) exploration of virtual maps. The system is able to display haptically the height profile of a map, through a tactile mouse. Moreover, spatial auditory information is provided in the form of virtual anchor sounds located in specific points of the map, and delivered through headphones using customized Head-Related Transfer Functions (HRTFs). The validity of the proposed approach is investigated through two experiments on non-visual exploration of virtual maps. The first experiment has a preliminary nature and is aimed at assessing the effectiveness and the complementarity of auditory and haptic information in a goal reaching task. The second experiment investigates the potential of the system in providing subjects with spatial knowledge: specifically in helping with the construction of a cognitive map depicting simple geometrical objects. Results from both experiments show that the proposed concept, design, and implementation allow to effectively exploit the complementary natures of the “proximal” haptic modality and the “distal” auditory modality. Implications for orientation & mobility (O&M) protocols for visually impaired subjects are discussed.     

Evaluation of a university website’s usability for visually impaired students

Today websites are the tools most commonly used to access information. People with disabilities face difficulties accessing or using information, and the importance of website usability in their lives needs to be recognized. Visually impaired students need to be able to use university websites that inform them about the opportunities and events taking place on campus. This study aims to evaluate the usability of a university website by visually impaired students. In this research, six visually impaired students were interviewed. The assistive technologies they use, as well as the various web pages they wished to use unaided were identified. Following data collection, usability tests were conducted and satisfaction surveys were completed. The usability test was done with five visually impaired students. They were asked to think aloud while performing 11 tasks involving their university’s web pages, including the main page and the pages of student affairs, library and departments and then to accomplish these tasks. In this test, five tasks were not successfully completed by all students. According to the test results, finding final exam dates on the academic calendar posed major difficulties, and accessing the course schedule web page was the task that required the most time. The test results indicated the need for a search engine on each page, a text version for all pages, rearrangement of the web link sequences with tabs and more information about visuals. Suggestions related to the visually impaired students’ needs were offered.     

Simulating a full screen of braille

A comparison is made between traditional embossed braille, which provides important information about page format, and speech, which presents information sequentially, thus losing page format information. Advances in technology have led to the advent of machines with dynamic braille displays which present the equivalent of a single line of embossed braille and which also provide computer access to blind users. These devices retain many of the advantages of embossed braille with added features such as editing flexibility. However, with speech-based systems, they do not present the user with the spatial relationships among the words on a page, the format information of a page layout, or the structure of columnar information. It was hypothesized that these format characteristics were important to locating information on a page, and that if these could be restored, the reader would operate more efficiently. A test apparatus was devised and a testing methodology was developed to test this thesis. The apparatus simulated a situation in which the reader utilized a single-line dynamic braille display mounted on a track so it could be moved vertically from line to line, much as one might move one's hands when scanning a page of embossed braille. This gives the reader direct feedback through arm location as to where he is reading on the page. Testing consisted of having subjects read sections of text and columnar information, and then respond by locating the answer in the text. It was discovered that physically scanning up and down the document allowed the users to develop a clearer sense of the overall gestalt of the page. Furthermore, readers were able to locate information using this technique approximately 80% faster than when using a single-line dynamic display which required the use of pushbuttons or a joystick to navigate around the page.     

Assisting Visually Impaired People to Acquire Targets on a Large Wall-Mounted Display

Large displays have become ubiquitous in our everyday lives, but these displays are designed for sighted people.This paper addresses the need for visually impaired people to access targets on large wall-mounted displays. We developed an assistive interface which exploits mid-air gesture input and haptic feedback, and examined its potential for pointing and steering tasks in human computer interaction（HCI）. In two experiments, blind and blindfolded users performed target acquisition tasks using mid-air gestures and two different kinds of feedback（i.e., haptic feedback and audio feedback）. Our results show that participants perform faster in Fitts＇ law pointing tasks using the haptic feedback interface rather than the audio feedback interface. Furthermore, a regression analysis between movement time（MT） and the index of difficulty（ID）demonstrates that the Fitts＇ law model and the steering law model are both effective for the evaluation of assistive interfaces for the blind. Our work and findings will serve as an initial step to assist visually impaired people to easily access required information on large public displays using haptic interfaces.     

Accessibility of audio and tactile interfaces for young blind people performing everyday tasks

Increasingly, computers are becoming tools of communication, information exploring and studying for young people, regardless of their abilities. Scientists have been building knowledge on how blind people can substitute hearing or touch for sight or how the combination of senses, i.e., multimodalities, can provide the user with an effective way of exploiting the power of computers. Evaluation of such multimodal user interfaces in the right context, i.e., appropriate users, tasks, tools and environment, is essential to give designers accurate feedback on blind users’ needs. This paper presents a study on how young blind people use computers for everyday tasks with the aids of assistive technologies, aiming to understand what hindrances they encounter when interacting with a computer using individual senses, and what supports them. A common assistive technology is a screen reader, producing output to a speech synthesizer or a Braille display. Those two modes are often used together, but the research studied how visually impaired students interact with computers using either form, i.e., a speech synthesizer or a Braille display. A usability test has been performed to assess blind grade-school students’ ability to carry out common tasks with the help of a computer, including solving mathematical problems, navigating the web, communicating with e-mail and using word processing. During the usability tests, students were allowed to use either auditory mode or tactile mode. Although blind users most commonly use a speech synthesizer (audio), the results indicate that this was not always the most suitable modality. While the effectiveness of the Braille display (tactile user interface) to accomplish certain tasks was similar to that of the audio user interface, the users’ satisfaction rate was higher. The contribution of this work lies in answering two research questions by analysing two modes of interaction (tactile and speech), while carrying out tasks of varying genre, i.e., web searching, collaboration through e-mail, word processing and mathematics. A second contribution of this work is the classification of observations into four categories: usability and accessibility, software fault, cognitive mechanism and learning method. Observations, practical recommendations and open research problems are then presented and discussed. This provides a framework for similar studies in the future. A third contribution of this work is the elaboration of practical recommendations for user interface designers and a research agenda for scientists.     

Multiple spatial sounds in hierarchical menu navigation for visually impaired computer users

This paper describes a user study on the benefits and drawbacks of simultaneous spatial sounds in auditory interfaces for visually impaired and blind computer users. Two different auditory interfaces in spatial and non-spatial condition were proposed to represent the hierarchical menu structure of a simple word processing application. In the horizontal interface, the sound sources or the menu items were located in the horizontal plane on a virtual ring surrounding the user’s head, while the sound sources in the vertical interface were aligned one above the other in front of the user. In the vertical interface, the central pitch of the sound sources at different elevations was changed in order to improve the otherwise relatively low localization performance in the vertical dimension. The interaction with the interfaces was based on a standard computer keyboard for input and a pair of studio headphones for output. Twelve blind or visually impaired test subjects were asked to perform ten different word processing tasks within four experiment conditions. Task completion times, navigation performance, overall satisfaction and cognitive workload were evaluated. The initial hypothesis, i.e. that the spatial auditory interfaces with multiple simultaneous sounds should prove to be faster and more efficient than non-spatial ones, was not confirmed. On the contrary—spatial auditory interfaces proved to be significantly slower due to the high cognitive workload and temporal demand. The majority of users did in fact finish tasks with less navigation and key pressing; however, they required much more time. They reported the spatial auditory interfaces to be hard to use for a longer period of time due to the high temporal and mental demand, especially with regards to the comprehension of multiple simultaneous sounds. The comparison between the horizontal and vertical interface showed no significant differences between the two. It is important to point out that all participants were novice users of the system; therefore it is possible that the overall performance could change with a more extensive use of the interfaces and an increased number of trials or experiments sets. Our interviews with visually impaired and blind computer users showed that they are used to sharing their auditory channel in order to perform multiple simultaneous tasks such as listening to the radio, talking to somebody, using the computer, etc. As the perception of multiple simultaneous sounds requires the entire capacity of the auditory channel and total concentration of the listener, it does therefore not enable such multitasking.     

Evaluation of multimodal graphs for blind people

This paper introduces the development of a multimodal data visualisation system and its evaluations. This system is designed to improve blind and visually impaired peoples access to graphs and tables. Force feedback, synthesized speech and non-speech audio are utilised to present graphical data to blind people. Through the combination of haptic and audio representations, users can explore virtual graphs rendered by a computer. Various types of graphs and tables have been implemented, and a three-stage evaluation has been conducted. The experimental results have proven the usability of the system and the benefits of the multimodal approach. The paper presents the details of the development and experimental findings, as well as the changes of role of haptics in the evaluation.     

An Open Road Evaluation of a Self-Driving Vehicle Human–Machine Interface Designed for Visually Impaired Users

ABSTRACT

Fully autonomous or “self-driving” vehicles are an emerging technology that may hold tremendous mobility potential for individuals who are visually impaired who have been previously disadvantaged by an inability to operate conventional motor vehicles. Prior studies however, have suggested that these consumers have significant concerns regarding the accessibility of this technology and their ability to effectively interact with it. We present the results of a quasi-naturalistic study, conducted on public roads with 20 visually impaired users, designed to test a self-driving vehicle human–machine interface. This prototype system, ATLAS, was designed in participatory workshops in collaboration with visually impaired persons with the intent of satisfying the experiential needs of blind and low vision users. Our results show that following interaction with the prototype, participants expressed an increased trust in self-driving vehicle technology, an increased belief in its likely usability, an increased desire to purchase it and a reduced fear of operational failures. These findings suggest that interaction with even a simulated self-driving vehicle may be sufficient to ameliorate feelings of distrust regarding the technology and that existing technologies, properly combined, are promising solutions in addressing the experiential needs of visually impaired persons in similar contexts.     

Blind and visually impaired people studying computer science and mathematics

The author runs an educational experiment at his university where blind and visually impaired people can study computer science or mathematics under conditions adequate to their disabilities. The project is now in its first semester. The paper reveals the problems blind and visually impaired students are presently facing, and it describes the methods used in our educational experiment to overcome these difficulties. It also reports our experience with the project gained so far. An appendix is devoted to a brief survey about the technology used to make computers accessible to blind and visually impaired people.