ADA Definition: Assistive [Adaptive] Technology is any aid or device that provides individuals with disabilities with an effective method to access information that has traditionally been inaccessible because of a disability.
Screen Readers and Synthetic Speech Access
A synthetic speech system is composed of two parts: the synthesizer that does the speaking, and the screen reader that tells the synthesizer what's on the screen to "read." The synthesizers used with PCs are text-to-speech systems. Their programming includes the grammatical rules of a language. This allows them to pronounce words correctly. Sometimes, names and compound words can cause problems because they often contain unusual spellings and/or letter combinations.
The synthesizer can be a card that is inserted into the computer, a box attached to the computer by a cable, or software that works with the computer's sound card. Some synthetic speech sounds robotic, although some can sound almost human. Prices range from approximately $150 to $1,300.
The speech program is software that works in conjunction with the synthesizer. A user may read the screen by: (1) pressing different key combinations on the computer keyboard; (2) pressing keys on a separate keypad; or (3) automatically when changes occur on the computer screen. These actions instruct the synthesizer to read a word, line, or full screen of text. Different key combinations are used to spell a word, find a string of text on the screen, announce the location of the PC cursor or focused item, and so on. They can also perform more advanced functions such as: locating text that is written in a certain color, reading predesignated parts of the screen on demand, or reading text that is highlighted - allowing the user to know which is the active choice on a menu. They also permit the user to employ the spell checker in a word processor or to read the cells of a spreadsheet.
There are screen access programs available currently for use with PCs running DOS, Windows 95, Windows 98, Windows NT, Windows 2000, and Windows XP. Each incorporates a different command structure and most support a variety of speech synthesizers. Prices range from approximately $400-$1500.
Evaluating and Purchasing a Windows Screen Reading Program
- What version of Windows will be used? Is the screen reader compatible with this version of Windows?
- Are there standard system configurations with which the screen reader does not work (color schemes, common video cards, etc.)?
- What synthesizers are/are not supported?
- From among the applications that will likely be used, are there some with which the screen reader does not work, no matter the skill level of the user?
- How much "automatic" speech does the screen reader give when the user is performing standard Windows functions such as selecting menu items or moving through items in dialog boxes? Can the amount of speech be adjusted to suit the user's skill level and preferences?
- How difficult is it to change simple standard features such as voice rate or the choice of a reading key?
- What must the user do in order to make an unfriendly program work well enough to be usable?
- What useful and unique features does the screen reader have?
- What problems does the screen reader add to Windows use?
- Is the manual accessible and accurate?
- Is there a tutorial in a usable format?
- If you are a computer lab considering this purchase, what program is being used by your school system or campus?
Screen Magnification for a Computer
Screen magnification software is used to magnify the text and graphics that appear in programs and applications.
Most of today's screen magnification programs are compatible with Windows 95, 98, and NT, Windows 2000, and XP. Magnification programs compatible with DOS text and graphics are still in use. Windows-compatible screen magnification products cost approximately $350 to $600. For those who need more than magnification, it is possible to use screen magnification and synthetic speech together. There are also large-print text editors and word processors - specialized programs that combine features of screen magnification programs and text editors or word processors. Such programs cannot be used as general purpose magnification programs. Prices range from about $30 (for shareware distributed programs) to about $300.
The magnification available varies - the least expensive screen magnification products limit magnification to 2x and some of the more expensive products provide up to 32x magnification. A limitation of screen magnification software (and magnification in general) is that as on-screen material is magnified, less of it fits on the screen.
Magnification programs function similarly to a magnifying glass moving over a page. Programs can automatically follow the cursor, magnifying the area around it. It is also common to be able to automatically move across and down a magnified page at a preset speed. Additionally, in the event of losing your place in a magnified document, programs can show the unmagnified screen, emphasizing the magnified area with color or shading. Fonts used in magnification programs are usually designed to smooth out the jagged or "stair-step" appearance of computer-produced diagonal or curved lines. Most programs allow the user to change colors.
Most Windows screen magnification programs can magnify all screen items, including the mouse pointer, text cursor, icons, buttons, and title bars. In addition, some programs provide a set of mouse tracking features, such as the option to link the mouse pointer to screen movement, increase the size and visibility of the mouse pointer, and limit mouse movement to horizontal or vertical directions only. Others offer the ability to use a sound card to provide basic screen reading.
Windows 95 screen magnification programs also offer a variety of screen options for viewing the magnified area of the screen. Common features include a viewfinder that can be moved around the screen, a feature that splits the screen into magnified and unmagnified areas, and the ability to automatically move across and down a magnified page at a preset speed. Other features include breaking lines of magnified text automatically so that they fit on the screen and the option of selecting various contrast levels.
Most programs work with many but not all video drivers built into Windows 95. Manufacturers often recommend a specific driver, resolution, and color depth setting. Even when they do, users may need to experiment to get the program to run properly.
Closed Circuit Television
A closed-circuit television (CCTV) system uses a stand-mounted or hand held video camera to project a magnified image onto a video monitor or a television (TV) screen. There is considerable versatility in types of CCTV systems available today. Cameras with zoom lenses provide variable magnification and are used in the more expensive CCTVs. In most of these systems, magnification level and focus are set after choosing a comfortable and functional working distance between the camera and the material to be viewed. Lower cost CCTVs often use cameras that have a fixed focus and cannot vary magnification or camera-to-target distance.
Cameras that are mounted on a fixed stand require the reading material to be placed under the camera and moved across and down the page. Stand-mounted cameras are particularly effective for handwriting because a hand can fit under the camera. To make the process of viewing easier, a table that is movable from the top of the page to the bottom and side to side is used with most stand-mounted cameras.
In contrast to stand-mounted cameras, hand held cameras are portable systems designed for bringing the camera to the material to be viewed. They can magnify almost anything within reach, including labels on packages of food and medicine. Hand held cameras are often on rollers, which make them easier to move across a flat working surface. When used in conjunction with a small (5" screen) video monitor or TV, hand held cameras can be highly portable. Some manufacturers of CCTV systems that use hand held cameras offer a writing stand as an accessory.
Assistive Software for Viewing the Internet
A new generation of software has been developed to assist the blind or visually impaired user to access the Internet. Using the keyboard to navigate, a person who is blind or who has a visual impairment can hear the full range of Web page content provided in a logical, clear, and understandable manner. If the objective is to access email or just surf the Internet, one of the programs in this category may be for you!
Typically, these programs speak text, frames, image and text links, alternate text for images and image maps, form elements including JavaScript, graphics descriptions, text in column format, and data input fields. It even includes special table navigation features that allow users to understand even the most complex tables, such as television listings.
Reading Machines
Reading Machines come in two configurations; stand-alone or computer program. They both use Text to Speech (TTS) software to convert machine produced text in to the spoken word. With either configuration you can read a single page or a complete book.
The software programs allow for editing of your information on the fly. These programs can be used with a variety of off-the-shelf scanners. The stand-alone machines do not require knowledge of computer skills to operate them. This reduces training time to a minimum. The two configurations range in price from $995 to $3,300.
Updated 03/13/2008
Printer Friendly
Text Version 
Email Page
