For persons with physical, sensory, and/or cognitive disabilities, computers can provide a whole new realm of independence. Computer hardware and software can speak for non-verbal persons; read for persons with blindness or low vision; assist individuals with learning disabilities to more easily perform cognitive activities; allow persons who are deaf to communicate by phone; activate environmental controls for persons with paralysis; and much more.
For someone who knows little or nothing about computers, however, the prospect of selecting and purchasing the appropriate hardware and software to meet their individual needs can be overwhelming. The following is a brief introduction to the different types of computer technology available for persons with disabilities.
A good first step in looking into computer equipment is to focus on whether someone needs help inputting information into a computer, or receiving output from a computer, or both.
For anyone who either cannot use, or cannot easily use, a standard keyboard because of motor function or visual limitations, alternative input interfaces, modified keyboards, or voice input may be solutions.
a. General Input Interfaces
These devices/software provide an alternative means of controlling the cursor on the computer screen. These interfaces would replace or be used in addition to the standard keyboard. An eye controlled input system involves an interface which tracks the eye movements of the user as he/she looks at different squares on an on-screen keyboard. This sophisticated system accepts the key indicated on a square if the user's gaze remains on that square for longer than 2 seconds. On-screen keyboards can also be used with touch screens. These monitor attachments allow the user to touch on a key-square with a fist, finger, headwand or mouthstick. A mouse, while often not considered specific to persons with disabilities, can be coupled with software to click and point to keys on-screen or otherwise control the cursor without using the keyboard. Trackballs work essentially as "upside down" mouse units, and allow persons with limited hand and arm motion to spin a rotating ball in the direction they wish the cursor to move, rather than having to move the entire unit.
b. Keyboard Modifications and Modified Keyboards
Sometimes a simple modification to a keyboard or a keyboard with a different layout than the standard QWERTY layout (this is the name assigned to any keyboard configuration with the Q, W, E, R, T, and Y keys at the top left portion of the alphabetical keypad) is all that is required to make a computer more accessible to people with limited hand function. Keylocks are keyboard modifications designed to enable the user to press more than one key at a time. For example, to use the function keys with Shift, Alt, or Control as many programs require, the user must depress two keys at once. For someone using a mouthstick, this becomes difficult, if not impossible. Keylocks are designed to attach to standard keyboards and to pivot onto a key, thereby "holding" it in a depressed position so that a second key can be pressed at the same time. Sticky key functions and programs perform in much the same way. The "sticky" comes from the fact that these programs tell the computer to extend the function time of a keystroke beyond the moment in which the key is actually depressed. The computer then accepts the next key pressed as the "second half" of a function command. For example, with a sticky Shift key, when the Shift key is pressed, the computer waits for a second key to be pressed before acting on the input. On the other hand, many keyboards will respond to prolonged depression of a key with multiple key strokes of that key (e.g. depressing the "k" key for more than a second will produce "kkkkkkkkk" until no longer depressed). An auto repeat function disabler tells the computer to indicate on screen only one character per key depression, regardless of how long the key is depressed. This type of device is helpful to individuals with limited hand/arm control.
Keyguards and keyboard overlays are keyboard accessories. They can help decrease the number of unwanted keystrokes (due to someone with poor manual coordination hitting more than one key at a time, for example), keep the mechanics of a keyboard safe from the effects of spills and drooling, and help individuals identify the keys. Braille keytop overlays provide blind computer users with the Braille equivalent of the information printed on the keys for easier keyboard navigation. Similarly, there are large print keytop overlays to help persons with low vision to read the keys.
Modified keyboards include expanded keyboards and keypads to provide a larger target area per key; one hand keyboard configurations to increase the typing speed and efficiency of persons with the use of only one hand (often called Dvorak keyboards); and split keyboards which allow the two sides of a keyboard to be positioned independently of one another to allow greater access by the user. Keyboard interfaces also include hand-held units which do not require "typing" in the traditional sense but rather pressing a succession of different buttons to perform all the functions of a standard keyboard. Keyboard interfaces also include devices and programs which allow keyboard input by means of puff/sip (pneumatic) switches, touch and contact switches, scanning selection, or morse code. Remote keyboards were designed for individuals who cannot position themselves close enough to the computer terminal to use the keyboard.
c. Voice Input
Computers and cursor movement can also be controlled by using one's voice. Through voice recognition technology, the user speaks into a microphone and the commands and text are relayed to the computer. These systems involve both hardware and software, but once set up can be used with many different types of software packages. Voice input can also be used for purposes of environmental control (turning on and off lights, adjusting room temperature, operating appliances, etc.) when coupled with an environmental control unit or program.
In general, modified output devices and programs are designed to benefit individuals with sensory disabilities. Output refers to information displayed on-screen as well as to hard copy printouts.
a. Screen Output Options
The design of standard computer monitors assumes an individual can visually digest the information displayed there. For persons with 20/20 (whether natural or corrected to 20/20) vision, confirmation of what was input into the computer, response to computer generated questions, and perusal of computer-generated results is as easy as looking at the monitor. For persons with blindness or low vision, however, no information or responses can be conveyed by means of the monitor without technical assistance. With the use of speech synthesizers and screen review software, persons who are blind can access monitor output by hearing what sighted individuals see. Voice output screen review software, or screen readers, convert strings of characters into auditory voice output, and the speech synthesizers act as the voice for this output. This technology has become so advanced that the choice of speech synthesized "voices" now include child or adult, female or male, and different accents. Screen readers can be used with many different commercially-available software packages including word processing, spreadsheet, and database applications. There are even several screen reading programs for use in Windows environments.
Voice output also assists individuals with learning disabilities by providing auditory reinforcement to visual learning.
Braille displays provide Braille readers with tactile feedback of information which would otherwise be displayed on screen. These devices have rows and columns of pins which are raised electronically to form Braille characters. This dynamic display operates like a three-dimensional ticker-tape which is "read" by the user's fingers.
For persons with low vision, large print programs are available which magnify the screen display and/or display the information in different contrasting colors. These programs often work with both text and graphics. Special features such as automatic scrolling, toggling between large print and page view, underlining, and contrast adjustments make these programs customizable to the specific needs of the user. Screen magnifiers can also be used to provide enhanced screen output at a constant rate of magnification. These devices often take the form of a monitor attachment.
Closed-circuit televisions, or cctv's, are also computer-compatible for use magnifying any written text, including handwriting.
Visual beep indicators alert individuals with hearing disabilities to computer "beeps" produced when something is wrong with the computer, when a function of the computer or a program cannot be performed or when the computer generates a question or message for the user by means of a visual message on screen.
b. Hard Copy Output
Braille printers used in conjunction with text-to-braille translation programs allow not only text but also graphics to be printed out in Grade 1 or 2 Braille and/or raised dot configurations for Braille readers. Some software programs also print text in Braille on regular paper for individuals learning Braille.
Similarly, large print programs can print text in various enlarged fonts from a variety of software packages. Many word processing packages available on the market, however, allow text to be printed in enlarged fonts without any special software additions or print options.
In addition to input and output options, computers can also perform tasks and assist individuals with training, education, organization and recreation. Software packages have been developed for use on a variety of computer systems and models for computer-assisted instruction, cognitive and motor skills training, communication skills training, learning living skills, professional evaluations, and functional applications such as communication, environmental control, job readiness training, office and financial management, etc.
The ABLEDATA database of assistive technology and rehabilitation equipment for persons with physical, sensory, and cognitive disabilities and seniors can help in the search for the appropriate computer equipment to meet specific needs. To see a list of all of the computer-related assistive products, go to "Products" section of the ABLEDATA Web site (http://www.abledata.com), and click on "Computers," or call the ABLEDATA office at 800-227-0216 in the U.S. or 301-608-8998 (V) or 301-608-8912 (TT) and request a database search on a particular product (screen readers) or product area (Computer Assisted Training for Communication Skills). You can use the product information available from ABLEDATA to contact manufacturers directly for more specific details, or you can share the information with an occupational therapist, job coach, teacher, or another rehabilitation professional. By combining the information from the ABLEDATA database with professional evaluations — and even with hands-on trials at a demonstration center or trade show--you will be better equipped to make a decision about which assistive technology product is best for you.
This Fact Sheet is provided by AbleData, an assistive technology information service provided by the U.S. Department of Education’s National Institute on Disability and Rehabilitation Research (NIDRR). Neither the Department nor ICF Macro, which operates AbleData, has examined, reviewed, or tested any product, device, or resource contained in AbleData or referred to in this Fact Sheet. The Department and ICF Macro make no endorsement, representation, or warranty express or implied as to any product, device, or other information set forth in AbleData. The views expressed herein do not necessarily represent the opinions of the Department, NIDRR, or ICF Macro. For the original full text of this Fact Sheet, please go to the “”Library” section of www.abledata.com.