for hearing impaired people

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1 TCT Education of Disabilities, 2002 Vol. 1 (1) Computer education and assistive equipment for hearing impaired people Hiroshi MURAKAMI, Hiroki MINAGAWA, Tomoyuki NISHIOKA and Yutaka SHIMIZU Department of Information Science Tsukuba College of Technology, Ibaraki Japan Abstract: Computer education for the hearing impaired student was studied. Various errors in computer programming were analyzed for the past ten years. Although there was difficulty in perceiving an auditory warning from a computer, no drawback in the aptitude for programming was found. Two aids for improving the computer education for the hearing impaired people were considered further. One is an alternate receptive device with an auditory warning. The second is lecture equipment for group education in overcoming the hearing difficulty. Elaboration for educational equipment and slight improvement of human interface seemed to be important for hearing impaired people in computer education. Key Words: computer education, hearing impaired, programming error 1. Introduction There is a law in Japan stating that 1.8% of a company's employees must be handicapped people. Particularly, about 370,000 people are acknowledged as being severely hearing impaired. Efforts to assist their social independence are required now. Because of this, the Tsukuba College of Technology was established as the only national college to educate hearing impaired or visually impaired people. Computer related occupations are promising for hearing impaired people. The Tsukuba College of Technology has the Division of Information Science for computerrelated education. The objective of the present study is to analyze computer education for the hearing impaired at the Division of Information Science during the past 10 years, and to improve the educational system for hearing impaired students. The students whom we educate fall into the range of hearing loss in excess of 60dB and they can barely receive speech by a hearing aid. Therefore, some adaptation for computer education is needed. It is necessary to confirm at computer-related work is suitable as an occupation for the hearing impaired. Therefore, tendencies of software errors observed in computer programming are analyzed. According to the resulst examined, it is considered that some assistance is needed. Furthermore, special adaptation seems to need for group lessons for the hearing impaired. 2. Aptitude for computer related works To confirm whether hearing impaired people have the aptitude for computer related works is important. Cumulated data in computer education during the past 10 25

2 operation ""known error 14% 3o syntax ~ ^. /- error "Y 48% logical 11 mmmssf error 35% Fig. 1 Ratio of observed errors in programming categorized by operation, syntax and logical errors. years were analyzed. Examined computer tasks in this study were a numerical computation and an image processing by the C programming under the X Window System and the Java. The observed errors are classified as the following four categories: operation errors, syntax errors, logical errors, and other errors by unknown causes. Fig. 1 shows the ratio of observed errors. operation errors These were found during the stage of the OS (Operating System) and several software applications. Since most of these errors were warned from a computer, the students noticed them easily. However the hearing impaired students could not hear the auditory warning. Stopping of the task because of hearing loss has been rarely observed. syntax errors As most of them were inexperienced they made mistakes in writing statements or missing by typing. Sometimes an inconsistency of parameter between subroutine and main-routine was recognized. logic errors The correct answer was not gotten or was stopped by mistakes in logic. These kinds of errors bothered many students and took a long time to correct. Typical examples of these errors are summarized in Table 1. Similar errors caused by syntax, or logical mistakes are observed frequently in normal hearing students. In addition, most of the hearing impaired students noticed the operation errors and corresponded correctly. Therefore, it was confirmed that hearing impaired students have the same ability to solve computer tasks as normal hearing students. In summary, there is no hindrance even if they hold a computer related occupation, except for sound related work, such as the watching or creation of a game by synthesized sound. 3. Improvement of computer operation to assist the hearing impaired Although hearing impaired students operate a computer in the same way as the 26

3 Computer education and assistive equipment for hearing impaired people Table 1 Example of errors observed in software training. operation errors fails file operation: erases files overwrites a bad file on an important file saves onto unknown partition misses current working directory stops operating system: inputs strange key misses the auditory warning syntax errors mismatch statements: constant: constant values versus variables variables: integer versus real { } [ ] (parentheses) typing errors: (. period) in stead of (, comma), (: colon) versus (; semicolon) etc. spelling (destroy in stead of destoroy) definition (RootWindow in stead of Rootwindow) mismatch subroutine: main (a, b, c) in stead of subroutine^, y) misuse function: mistakes usage of parameter ( XDrawLine(a,b,c) ) needs long variable( sin(x) ) logical errors jumps to wrong statement: return, break, while, else, else if divides by wrong variable: overflow or underflow mistakes logic: trap in loop stop running constructs wrong algorithm not obtain correct result hearing, human interface should be improved for them. A computer based on the GUI (Graphical User Interface) raises a serious drawback for a blind person because the human interface is made by a combination of the visual display terminal, the keyboard and the mouse1*. On the contrary, there is no serious problem for the hearing impaired except the failure to hear the sound of the speech synthesizer. Two considerations can be pointed out for computer operation for hearing impaired people. One consideration is to inform the sound which has emerged from a computer. 27

4 There are two ways to substitute for the sound alarm. One is to transmit the alarm visibly, and the other is to transmit on a tactile channel. Recent operating systems have a function which flickers on the visual display when a user has made a mistake. For example, the function can be set from the control panel by the handicapped support in the Windows and the Mac OS (Operating System). A screen flickering is also supported in the vi-editor of the UNIX OS. Although these famous OS present a visual warning, all applications do not always support this flickering at present. The second way is to present an alarm to the tactile sense. A device that vibrates a keyboard or a mouse by the alarm system will be considered. Fig. 2 shows a vibrating mouse that we have developed. Although the vibrating mouse that presents a screen image has been devised for the blind, the mouse for the hearing impaired is not so complicated2). This device receives an alarm signal from a sound port of a PC (Personal Computer) and activates a vibrator that is mounted on the mouse. The hearing impaired user perceives an alarm via the palm. Tasks using the mouse such as image processing and picture drawing are effective for our students. Another necessary consideration is to present information about the running state of peripheral devices connected to a computer. Since a working indicator is not clear, there exists a risky situation in which a person may forcibly pick up the read/write medium (the floppy diskette and the Magneto Optical diskette etc.). Recent technological progress has expanded this risk further, because any rise of mechanical noise during the access to the read/write medium has been suppressed. The mechanical noise from the peripheral device, sometimes gave an auditory cue to notice their accessing condition. Therefore much caution is needed to operate them. It can be said that the hearing impaired students do not always use the functions described above, i.e., it means that the hearing impaired rarely fall into a serious problem during their computer operation. Fig. 2 Illustration of vibrating mouse for the hearing impaired. Alarm is presented to the palm by a vibrator mounted in the mouse. 28

5 Computer education and assistive equipment for hearing impaired people 4. Assistance for computer education Some effort is needed when we practice computer education for the hearing impaired. The following equipment has been designed for this purpose. lecture A lecturer needs sign language as well as voicing at a usual lecture. Moreover, visual media such as graphs, charts and tables are used frequently for computer education. The hearing impaired student have to depend on vision more because of the defect of hearing. Therefore, designation of educational presentation is important for a lecturer. Since we often have to improve educational contents, the teaching material presented by the OHP, the slide projector or the video player is not ideal for frequent change. The recent PC is useful for this purpose. Application software that assists presentation such as the MS Power Point, commercially available now, is effective for a lecture. The merits of a PC introduced for computer education are as follows: (a) Since a communication line is established between students and a teacher by PCs, response from one student can be transferred to other students and a lecturer. (b) Since a hard copy of each presentation is easily delivered, efforts to take notes can be reduced. This fact is important because the students concentrate their sight on the lecturer's explanation. (c) Since a series of contents can be retrieved after each lecture from a database stored in a computer system, it is useful for a review of the lesson. Most students evaluated the lectures using PCs to be fine. The presentation system that we have designed for computer education is shown in Fig. 3. Large Sized LCI witri Touch Panel Screen Matrix Switdher Assistant s^ Languagey interpreter Pen Tablet OHP LAN (VMreless) at Ceiling Fig. 3 Structure of lecture room equipped with various presentation devices for the hearing impaired. 29

6 Fig. 4 Education system making use of a large LCD panel display. Recently, an LCD-panel beamer is used for visual presentations. However, a large sized PDP (Plasma Display Panel) or a LCD display with touch panel system is more effective for the following reasons: (a) Since the students need to get knowledge from a presented medium as well as a lecturer's sign language and lip shape visually, lighting is needed to illuminate the lecturer's mouse and the hands. This lighting demand decreases the contrast of the presentation. However, the flat panel display does not need any illumination to be seen. (b) Since the LCD projector radiates a strong light beam, a lecturer always feels a dazzling sensation from the strong light, except when in the rear projecting condition. However, the flat panel display does not radiate the strong beam directly to a lecturer. (c) Since the touch panel is available, comments by a lecturer can directly be written on the panel by a finger. This direct writing is effective for computer education because direct suggestions are important for software operation. Fig. 4 shows a scene of a lecture using a large sized flat display (Liquid Crystal Display). Students evaluated this system excellently. lesson for software operation For practical lessons for using the computer, man-to-man education corresponding to a student level is necessary. Ideally, 10 teachers are needed when we teach 10 students simultaneously. However, 2 teachers take charge of about 10 students in our lessons. Sometimes a teacher wants to transmit a comment that is common to all the students. A teacher's voice cannot reach the student's ears because of hearing impairment. Moreover, their attention is always concentrated on the visual display to solve their task. A chat system was applied to overcome the problem. Fig. 5 shows the training room in which the chat function was introduced. A teacher inputs a message from a PC terminal, when a comment is needed (left panel). Since a network system is established to each PC, the message from a teacher appears 30

7 Computer education and assistive equipment for hearing impaired people Fig. 5 A chat system that presents attention to each student, (a) before message, (b) after message. on each visual display with the first priority. Students respond by a message presented on the visual display (right panel). Any attention will be offered simultaneously even if the room light is turned on or off. 5. Concluding remarks Computer education for the hearing impaired students who study at the Tsukuba College at Technology was examined. It was clarified that they had the aptitude for the computer-related tasks. Therefore the situation that it is not a severe problem in getting a computer-related job seems to exist at present. However, some assistance that announces the warning signal from a computer is needed for the hearing impaired. The vibrating mouse was introduced for this purpose. Furthermore, an educational system to improve group lessons seems to be needed. The designed equipment was accepted by the students, since they were helpful for learning. However, further elaboration is needed to improve education for the hearing impaired. References 1) Shinohara M, Shimizu Y & Mochizuki A. Three-dimensional Tactile Display for the Blind. IEEE Transactions on Rehabilitation Engineering, 1998; 6(3): ) Shimizu Y, Shinohara M, Sasaki T, Watanabe T, Minagawa H & Nagaoka H. Assisting system for a GUI-based PC for the blind, in Edwards A, Arato A & Zagler W. (Eds) Computers and assistive technology, Osterreichische Computer Gesellschaft, Wien, 1998;