Assistive Technology for the Disabled Computer
User
By Linda Wilson, UNC-CH IAT Publications Intern
Revised by:
Jon Pishney,
Former UNC-CH
Institute for Academic Technology Publications Editor
Last updated: October
1996
Purpose
Introduction
Assistive Technology
Defined
Problem Areas for the
Disabled in Computer Access
Intended Users of the
Technologies
Current Technologies
· Visual
Impairments
· Mobility
Impairments
· Speech, Language and
Learning Impairments
Conclusion
Purpose
This technical paper has two purposes:
- To introduce administrators and staff of colleges and universities to the
assistive technology that helps the physically disabled student use a
computer; and
- To refer those who need more specific information -- whether on products
and prices, or on agencies that work with and assist the disabled -- to
resources in their area.
Introduction
The Americans with Disabilities Act (ADA), approved by Congress in 1990, has
broad implications for higher education. Although colleges routinely offer
disabled students services such as interpreters and readers, elevators,
wheelchair ramps and curb cuts on streets, access to computers is not as
widespread. The ADA not only requires employers to make reasonable adjustments
to accommodate the disabled in a job or work environment, but also mandates that
colleges and universities give disabled students equal access to computers on
public campuses.
The ADA reinforces two earlier laws that had a profound effect on American
education: the Rehabilitation Act of 1973, and its successor, Section 504. The
Rehabilitation Act prohibits discrimination against the handicapped at
institutions receiving or benefiting from federal funds. Section 504 of the
Rehabilitation Act, which took effect in 1977, requires the removal of barriers
that prevent the disabled from participating in higher education.
The ADA is likely to have two long-term effects on higher education:
- Increased enrollment of disabled students, many of whom would have been
too discouraged to apply for admission before passage of the ADA.
- Financial savings to colleges and universities. One-time expenditures on
assistive technology for disabled students will be more than recouped as the
jobs of readers and helpers become obsolete. In addition, as the independence
and self-esteem of disabled students on campus increases, so too should
retention rates for these students.
Assistive Technology
Defined
Computers were designed to perform at maximum efficiency when used by the
nondisabled. But almost all of us employ some type of adaptive technology when
using the computer. Adaptive technology ranges from wearing eyeglasses or wrist
supports, to simply adjusting the brightness of the screen display or the height
and angle of the monitor.
Broadly defined, assistive technology includes any device or piece of
equipment that increases the independence of a disabled person.
Assistive technology for the disabled, of course, is not new. For instance,
the wheelchair has long been an indispensable assistive device for those with
impaired mobility.
The distinction between adaptive technologies employed by the nondisabled and
assistive technologies for the disabled blurs at times. Some of the assistive
technologies designed for the disabled have proven so ergonomically sound that
they have been incorporated as standard features. One such example is the
placement of the keyboard on/off switch, which was designed so that people with
motor impairments would not have to reach to the back of the machine to turn the
power on and off.
Assistive technology has increased enormously the ability of the disabled to
lead independent lives. Computer-based environmental control units allow
disabled users to turn on lights and appliances and open doors from a
wheelchair. Augmentative communication devices enable those who cannot speak to
voice thoughts and needs using touch- or light-activated keyboards coupled to
synthetic speech systems. Screen reading programs for the blind, screen
magnification systems for those with low vision, and special ability switches
that permit the mobility-impaired to use a computer are only a few examples of
the technology by which the disabled gain access to the computer screen and
keyboard.
Although this paper addresses only those assistive technologies that help the
disabled use a computer, more information on environmental control technologies
and augmentative communication may be obtained through many of the resources
listed in the Assistive Technology Web Reporter.
Problem Areas for the Disabled in
Computer Access
The disabled user wants access to the personal computer or network
workstation for the same reasons as the nondisabled. However, modifications and
even alternatives to standard computer hardware and software are often necessary
to make the computer accessible to the disabled user.
The standard personal computer system -- disk drive, keyboard, mouse, monitor
and screen -- can present barriers to certain disabled users. Some common access
problems are discussed below:
- Disk drive -- Handling diskettes is impossible for some users due
to lack of strength or dexterity. In addition, those with impaired mobility
may not be able to turn the computer on or off if the power switch is located
to the rear of the hardware, as is frequently the case.
- Keyboard -- The standard QWERTY keyboard used on most personal
computers is often inaccessible to people with impaired mobility or fine motor
control. Many disabled users do not have the strength required to press the
keys on a standard keyboard. Those with limited range of motion are not able
to move their hands easily from the alphabetic keypad to the arrow keys,
function keys or number keypad. Other users with uncontrolled or involuntary
hand movements make frequent typing errors by pressing the wrong key, or by
pressing a key longer than normal, inadvertently activating the automatic
key-repeat feature of many keyboards.
- Mouse --Using a standard two- or three-button mouse may not be
possible for those with impaired vision, mobility or motor control; successful
use requires not only sufficient vision to follow the graphical representation
of the mouse on-screen, but also adequate fine motor control and strength to
activate and control the mouse. Manipulating text and graphic displays by
clicking, pointing and dragging with the mouse is an acquired computer skill
for all users, and requires considerable practice before mastery. Use of a
mouse also requires sufficient strength and motion in the shoulder and arm to
position and manipulate the device on the desktop or mousepad.
- Monitor and Screen -- The screen display is not accessible to blind
users or those with low vision without magnification or text-to-speech
conversion. On the other hand, the screen display is accessible to the deaf
user, but requires modification so that audible error messages or "beeps" are
converted to text that the deaf user can read.
Intended Users of the
Technologies
Five areas of human functioning -- the ability to see, to hear, to move about
freely, to speak and to learn -- are so critically important that by almost any
criteria, irreversible loss of any one of these abilities is disabling. Among
college and university students, access to computers is most often compromised
by impairments of vision, hearing and mobility.
For the disabled user with low vision, access to the computer requires one or
more means of assistance: speech, large print or Braille. The blind user employs
speech, Braille, or a combination of the two.
The hearing-impaired or deaf user usually adapts most easily to using the
computer, since the standard medium of exchange between user and computer is
visual. Often only minor modifications, such as an alternative to the audible
warning beep, are needed for this user.
Users with impaired mobility and motor disorders must be evaluated carefully
so that their best remaining function is incorporated in the plan of access to
the computer. The ability to stand and walk unassisted, the range of motion of
the joints and spine, and any loss of muscle strength, motor control or
coordination are all considered when selecting the appropriate assistive
technologies. A disabled user whose best voluntary, controlled movement is the
raising of an eyebrow can be fitted with a switch to access the keyboard. Those
with impaired mobility use alternative input devices such as joysticks, ability
switches and modified keyboards. Keyguards cut down on extra keystrokes, while
software modifications deactivate the automatic keystroke repeat feature.
Current Technologies
Visual Impairments
The technology available to disabled computer users who are blind or have low
vision is extensive. The choice of the appropriate technology depends on a
number of factors. Among these are the cause of the visual loss, the extent of
loss of visual acuity, the quality of peripheral vision, and any other physical
or mental limitations that might affect use of a computer. What follows is a
general description of the major types of technology available to the blind or
low-vision computer user.
Screen reading programs usually consist of two parts: a software program and
a speech synthesizer. The software program, working as an overlay between a
popular off-the-shelf application program and the disabled user, directs
keyboard input to the speech synthesizer.
The speech synthesizer typically attaches to a computer's RS232C port and
converts standard ASCII text into speech. The synthetic speech can be directed
to headphones, so that it does not disturb others. The user has the option of
controlling the output of the speech synthesizer in several ways; for example,
the rate of speech produced may be adjusted, or the output may be read
character-by-character, or line-by-line. When spelling out words or numbers, the
synthesizer can often be set to pronounce all spaces and punctuation marks as
well. For example, a capital letter might be read with altered pitch. The
aesthetic quality of synthetic speech varies greatly, ranging from the metallic
quality of cheaper synthesizers to almost life-like voices.
Large print screen displays are created in one of two ways: stand-alone
software programs, or hardware- and software-based magnification systems.
Stand-alone software magnification programs enlarge the normal text display of
other application programs.
Screen magnifying systems employ both hardware and software adaptations to
magnify the screen display. Typically, users can customize the magnification to
their own preference. Other options include the ability to invert the screen
display to show dark letters on a light background, since many people find the
reverse display reduces eyestrain.
Braille computer systems allow users to access the screen display in Braille
one line at a time. The user types input from a keyboard. Fitting between the
user and the keyboard is a hardware device that accepts input from the keyboard,
and translates it line-by-line into a tactile Braille display for the blind
user. The Braille-based computer system is especially useful to those who work
with large amounts of data. Pocket Braille computers contain both speech
synthesizer and Braille keyboard. They are used as portable note takers, address
books, calculators and clocks.
Braille software translators and embossers enable users to print high-quality
Braille documents from a PC. The software converts the screen display to Braille
before it is sent to the Braille embosser to be printed. Reading systems perform
optical character recognition to convert printed text into speech or computer
files. The machines are limited to reading printed material only; handwriting
and most newspapers are often indecipherable.
Mobility Impairments
Many adaptations are available to assist those with impaired mobility use the
computer. Although a standard keyboard and mouse are the input devices of choice
for most people, other devices have been developed. Among the most frequently
used are modified and alternate keyboards, ability switches, and headpointers
and joysticks. These methods are used in many variations and combinations, based
on the abilities and needs of the mobility-impaired user. Whatever the method,
the computer treats the input from these methods as if it had been received
through the standard keyboard.
Modified keyboards include some relatively simple assistive technologies
designed to decrease the number of typing errors, and thus increase productivity
of those with impaired mobility. Descriptions of three of these follow.
- The keyguard is a lightweight overlay, often plastic, that fits over the
regular keyboard; holes are punched out of the plastic so that each standard
key can be pressed if chosen deliberately, either with the fingers or
mouthstick. The keyguard cuts down on accidental keystrokes substantially.
- Permanent large print key labels can be placed on each character, number
and punctuation mark of the standard keyboard. The visually impaired user may
benefit from this adaptation, as do children.
- Software exists that will disable the automatic-repeat feature of most
keys on the PC keyboard.
Alternate keyboards come in many styles. The keyboards consist of a series of
membrane switches arranged for ease of use. Some alternate keyboard designs keep
the standard QWERTY keyboard arrangement, but omit numbers and enlarge the
letter keys. Users who input only numeric data may opt for a keyboard consisting
entirely of enlarged numbers. Other keyboards are arranged so that the most
frequently used characters and numbers are in a central position. Miniature
keyboards are available for those with good pointing skills within a limited
area. Many alternate keyboards require a separate hardware interface unit
between the keyboard and the serial port, although the trend is toward alternate
keyboards capable of direct attachment to the keyboard port.
Ability switches provide access to the screen display without using a
keyboard. Optimum use of ability switches requires careful assessment of the
user’s best voluntary function. The switches can be mounted mechanically to
wheelchairs, desks or almost anywhere else the user might need the switch
positioned. Switch mounting systems often consist of adjustable arms attached to
clamps and allow many users who have severe motor disabilities to use a
computer. A switch interface unit acts as the link between the switch and the
computer.
Due to the wide variety of user abilities, many types of switches are
available. Switches exist that can be activated by only a raised eyebrow, if
that is the user’s most reliable movement. Ability switches can provide feedback
for users who require it. This feedback often occurs in the form of an audible
click upon activation. Commonly-used switches include the following:
- Button switch.
- Plate switch.
- Infrared switch.
- Sound-activated switch.
- Treadle switch -- for those with arm, elbow, foot or knee control.
- Pillow switch -- a soft, fabric-covered switch often used when activation
is by a facial movement.
- Sip-and-puff switch -- controlled by voluntary inhaling and exhaling,
frequently used by those with spinal cord injuries.
- Eyeglass switch -- activated by a purposeful eye movement.
- Arm slot control switch -- for those without fine motor control. Shifting
the arm among the five arm slots activates switches that reproduce joystick or
mouse control.
Operating a computer with switches involves learning one of two techniques:
- With scanning, the cursor moves repeatedly from one character, or group of
characters, to the next, often in a clockwise or counterclockwise motion. The
user selects desired characters or words from the computer display by
activating the switch when the cursor falls on that character or word.
- With direct selection methods, the user points to target items with a
headpointer, mouthstick or joystick. Pointing devices allow users who have at
least one voluntary, functional movement access to the computer.
Speech, Language and Learning Impairments
Online computer instruction is a particularly good medium for intensive
remedial training. The strengths of the computer in education include its
capacity for constant, individual feedback to the student along with an
unlimited ability to carry out drill and practice exercises until a subject is
mastered.
Computer packages have been designed to improve the speech and language
capabilities of those with poor hearing and speech, and also to assist those
with cognitive injuries or learning disabilities. Among the current
adaptations are vehicles for speech therapy and word prediction software
programs.
Some software increases the efficiency of speech therapy by synchronizing
audio playback with interactive graphic displays of the user’s speech. For
example, the hearing- or speech-impaired user speaks into a microphone, and
if, for instance, loudness is the attribute being measured, an on-screen
balloon inflates as she or he speaks at the desired level.
Word prediction software programs are beneficial not only to the learning
disabled, but also to users with mobility impairments. The programs operate in
a way similar to the spelling check feature found in many word processing
programs: as the user types the first letters of a word, the word prediction
program compares it to a dictionary of words that begin with those same
letters. A window appears on-screen with the list of words; if the user finds
his or her intended word in the list, one keystroke is all it takes to insert
the word into a document. If not, the user can continue typing until the
program presents the correct match. Proper names and terms not included in the
software can be added to the program's dictionary for future use. For those
with mobility impairments, the saving in keystrokes adds greatly to their
productivity. Dyslexic students also benefit from the word prediction
programs.
Conclusion
No doubt the scope of assistive technology for the disabled computer user
will enlarge in the future. New opportunities for the disabled student in
higher education will naturally lead to increased assimilation into the work
force upon graduation. Assistive technology for disabled computer users
supports the precept behind the Americans with Disabilities Act -- that the
disabled should have equal access to all opportunities.
URL: http://www.unc.edu/cit/guides/irg-20.html
Maintained
by: Carolyn
Kotlas
© Copyright 1994-96, The University of North Carolina at Chapel
Hill. All rights reserved.
May be reproduced in any medium for
non-commercial purposes.
Reproduced here by permission from UNC-Chapel Hill Center for Instructional Technology.
Although this document is somewhat dated(and no longer maintained), it nevertheless contains valid if not historical information.
