Article 1. Dynamic Displays

A "dynamic" or "transient" display is a computer screen that changes in response to user input. Information on the display can be pictographic or text-based. Color, various fonts, high resolution graphics, animation, speech, sound and even video are possible.

Powerful laptop computers with high-resolution displays have made dynamic display technology portable and useful for AAC devices. In a summary article, Woltosz contrasts the use of dynamic displays on AAC devices with static displays, i.e., symbols/words/letters printed on paper.¹ For years static displays were our only option, he says. Persons using AAC devices with static displays rarely have access to more than 128 symbols/ messages unless their overlays are changed or they learn codes (e.g., semantic encoding, abbreviation expansion). Literate users who spell and have unlimited access to language, need to learn codes or use linguistic prediction to reduce keystrokes and increase speed.

AAC devices with static displays place cognitive, motor, perceptual and learning requirements on persons using devices to communicate. Professionals also have experienced difficulty learning to use this equipment. Many feel transient displays substantially reduce these demands, as well as enhance rate. Why? The technology allows individuals to change screens quickly and to configure the size, color and arrangement of symbols, words and phrases on their screen. They can select (or construct) messages without remembering codes or physically switching overlays. Also, sufficient computer memory allows storage of libraries of pictures, symbols, animation, text, sounds and speech.

Features inherent in dynamic displays also carry cognitive, motor, visual-perceptual and learning loads that challenge some users. For example, moving between and among screens to construct messages requires visual attention and decision-making. Although memory demands are reduced, automaticity in generating messages (or parts of messages) may be difficult to achieve. Off-the-shelf computers are not designed to be mounted on wheelchairs and used as communication aids; however, concerns raised about their ruggedness remain unsubstantiated. We simply don't know about a lot of things –despite all the claims being made! Users, researchers, manufacturers and clinicians need to document their experiences so we can determine which individuals, with what types of abilities, benefit from what types of technology.

AAC devices with dynamic displays and several communication software packages are listed in Table I (not included). The Dynavox and Lingraphica are dedicated to communication; they are computers turned into communication devices. Lingraphica has features carefully designed for people with aphasia. The Dynavox is used by people across a broad spectrum of ages and disability categories. Dynasyms, a symbol system developed by Faith Carlson, and Dynawrite, a word processing program, make this a versatile device.

System 2000 is a complete communication system including an IBM-compatible computer, voice synthesizer and input device. Talking Screen and EZ Keys are soft- ware for use on System 2000 or other computers. Symbol options for Talking Screen are Mayer-Johnson.

The Gus Multimedia Speech System converts any Windows-compatible PC into a dynamic display device. It supports standard Windows bitmap pictures or any PC-compatible symbol set (e.g., Mayer-Johnson, Imaginart) and includes a synthesizer.

Speaking Dynamically runs on a Macintosh laptop computer. Developed at Mayer-Johnson for use with Boardmaker, this popular program provides access to their entire symbol set, a talking word processor, and more.

Talk-About will be released by Don Johnston Inc. in June, 1994. This text-based program is for literate individuals. It uses a dynamic display to provide a conversational structure. Based on pragmatic research at the University of Dundee, Talk-About allows users to identify their partner. The program can automatically shift conversational style and highlight topics and vocabulary relevant to that dyad. The display is configured so components of conversation are accessible. Users can greet, chat, introduce a new topic, tell a story or related experience and create novel messages using Co: Writer. Text can be saved on-the-spot and retold later.

KE:NX is a combination of hardware and software that now allows a user to address a broad range of communication needs

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When selecting a device with a dynamic display, consider the:

Final Comments

Will dynamic displays replace all devices with static displays? I doubt it. For one thing, people need access to language everywhere. Low-tech aids, which are static displays, will continue to be important. Also, some people prefer to use what is already familiar. Finally, the use of dynamic displays is relatively new. We need to document our observations and share information about whose needs can be met by this technology. There is, however, a growing chorus of enthusiasts in the AAC community for dynamic display technology; and many are consumers.