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Monday, July 22, 2013

Static Display in AAC

AAC refers to communication approaches that augment (add to) or serve as an alternative to speech.  It includes all methods that make communication easier or possible.  There are a great many options that fall under the heading of Augmentative and Alternative Communication.  A functional aac system is a compilation of strategies that allow the student to communicate effectively in an array of intents in an array of contexts, with all communication partners.  
At the no tech end of the scale are paper based systems that can range from simple picture displays and rotating choice options to complex Pragmatic Organized Dynamic Display books with more than 100 pages and Pixon boards of more than 100 icons.  At the high tech end of the range are a variety of dynamic display computerized systems; including dedicated devices, computer software, and tablet apps.  
In the middle are static display voice output devices.  These can have from 1 to 128 buttons, thought typically there are no more than 16 or 32.  These devices use recorded human speech and paper overlays that require someone with sufficient dexterity to change the overlay and, sometimes, the device ‘level’ button to match that overlay. Problem 1: Access. Those devices that offer multiple ‘levels’ to be pre-recorded to make the change of topic quicker are usually restricted to 7 or 8 or 12 levels.  Problem 2:  Breadth of vocabulary.  Each button can be a word, phrase, or sentence (or more).  But, typically, there is no ability to sequence buttons and retain them someplace from which they can be repeated as a fluid whole message.  Problem 3: Message construction.  Problem 4: Literacy.  If one can’t sequence buttons into a whole, one can’t create words.  There are no text-to-speech options here.
Static display devices are frequently used for choice-making or for responding in a specific context.  There is not sufficient vocabulary to meet all of a student’s needs.  There is not room for off-topic messages, clarifications, or comments.  There is little or no ability for genuine message construction.  Few of them provide scanning access for those who can’t direct select.  In most cases, the vocabulary location is not stable across overlays, making learning more difficult and obviating learning through motor planning.  In classrooms, these displays are most frequently used as activity-based displays.  The vocabulary is provided as needed in order of the activity and messages are chosen based on the steps of the activity. 
At the best possible scenario with static display, one can create overlays that use core vocabulary that is stable on every overlay and fringe vocabulary for specific topics, and have enough to cover a number of contexts - but likely not all.  Most kids can’t change the overlays themselves, so need a way to signal a change of topic to their partner.  Most kids are going to be limited in vocabulary learning and use with these limited displays and topics.  Most kids are not going to learn how to construct novel messages with a limited array of word choices.  Most are not going to learn literacy skills without the ability to sequence sounds. So, as a primary component of an aac system these devices fall a little flat for me.

This is not to say that static display devices don’t have their place.  They can be a valuable piece of an aac system.  And remember, aac is a system with multiple parts.  We all use more than just one way to communicate.  In fact, there are some amazing statistics about just how small a percentage of our communication is verbal.  But, back to the topic at hand - static display devices can be well used in a variety of communication contexts.  Given sufficient ‘buttons’ per page, it is possible to provide some basic core vocabulary for a small array of functions, as well as the fringe vocabulary basics needed for the activity or topic.  But for students to participate in their school environments, communicate effectively with their partners, and learn to use language effectively, I do not believe static display devices are sufficient to meet communication needs.  Click here to download a tech speak overlay template that provides some core vocabulary, as well as spaces to insert your own activity-related words.  
Please note that all symbols used in these displays are from Mayer-Johnson Co., a division of Dynavox.  The Picture Communication Symbols ©1981–2010 by Mayer-Johnson LLC. All Rights Reserved Worldwide. Used with permission.
Boardmaker™ is a trademark of Mayer-Johnson LLC.

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