AAC devices and systems: The main categories of AAC The following are the main categories of AAC. They do not represent the entire range of communication modes in use. This list focuses only on systems that require the child to be an intentional communicator and understand symbols. (See Assessing intentionality, and the understanding of means-end, causality and symbols.) It does not include the myriad other ways in which a child communicates intentionally or unintentionally, such as facial expressions, body position, muscle tone, vocalizations, etc.
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Aided vs. unaided AAC systems An aided AAC system is one that utilizes an external device. Examples are voice output communication devices (VOCAs), computers and communication boards. Unaided systems are those which are independent of a device, such as speech, vocalization, gestures or sign language. There are advantages and disadvantages to both types of systems.
In addition, it is highly recommended that a child be taught at least one unaided system, even if only for emergency purposes. The reason for this is that aided systems can be lost, stolen or otherwise unavailable. Lack of availability is one of the most common reasons for lack of use of AAC cited by adult AAC users (Murphy, Markova, Collins, & Moodie, 1996). Unless the child has an alternative mode, he or she may be without the means to communicate for a long period of time. (See Multimodal communication.)
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Issues with different AAC devices and systems Here are some of the many issues that need to be considered in the selection of an AAC device or system. Some of the answers will be inherent to the device or system itself, others have to come from the manufacturer of the device. (See Finding answers to specific AAC questions.)
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Issues with symbol systems A symbol is anything that represents something else. Symbols are useful because they allow us to refer to objects and events that are not currently present, or are abstract. A child who is pre-symbolic points at, looks at, gestures towards or otherwise refers to what is present and happening in the here and now. (See Assessing intentionality, and the understanding of means-end, causality and symbols and The first goal: Intentional communication.) Symbol systems include speech, sign languages, formal gesturing, and graphical systems (i.e. picture-, drawing- or text-based systems). The type of symbol system is somewhat determined by the choice of AAC. For example, speech encompasses English and other languages, sign language may be American or some other type, a graphical system may use pictures or the alphabet. (See The main categories of AAC.) Once the broad choices have been made, it is necessary to select the specific symbol systems to be used with each type of AAC. Although there are different types of sign language and gesturing systems from which to choose, discussions regarding symbol system selection typically refer to those used with communication boards, voice output communication aids (VOCAs), computers, and other graphical systems because the options are very diverse. The selection of a symbol system is important and individualistic. It cannot be decided by age, cognitive ability or developmental level of the child, although these do influence the decision. A predominant physical issue that impacts the choice of a symbol system is whether the child has a sensory impairment, which may affect his or her ability to perceive and process certain types of symbols. Children with visual impairments may require tactile or auditory symbols alone or in conjunction with enhanced visual symbols. (See Children with sensory disabilities.) In addition, it is important to consider whether the persons with whom the child will be communicating already know a specific symbol system. Choosing an already familiar symbol system means that teachers or family members do not have to learn a new one, and may have had some experience in teaching it. On the other hand, it is important to make sure that a particular symbol system is not being recommended simply due to someone’s desire not to have to learn a new system, or to lack of information about other systems (Romich & Zangari, 1989). (See Teaching symbols.) Sometimes a child will initially be taught one symbol system and then move on to a more abstract system that allows for increased sophistication of messages and speed of production. Studies have shown that, in general, the more concrete and real-looking the symbol, the easier it is learn to use, although the less flexible it is. For example, focusing on nouns, the order from easiest to hardest to learn among the following symbol systems is: objects, color photographs, black-and-white photographs, miniature objects (i.e. the identical object but on a smaller scale), black-and-white line symbols (including Picsyms, Self-Talk, Picture Communication symbols and rebuses), Blissymbols, and, finally, written words. (Beukelman & Mirenda, 1992; Reichle, York, & Sigafoos, 1991). A child who is a pre-intentional communicator, for example, may have to start out learning with concrete objects, and then move on to a more abstract and less cumbersome system. See Start with objects as symbols.) OTHER RESOURCES:
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Minspeak vs. Dynamic Display Related to the selection of a symbol system is its organization. The organization of symbols is very important because it establishes how a child locates a particular message, and, consequently, affects the speed (how long it takes) and efficiency (how many movements are required) to ouput a message. Currently among voice output communication aids (VOCAs), there are two predominant symbol organizational systems, Minspeak, also known as Semantic Compaction, which is associated with the Prentke-Romich Co. (www.prentrom.com), and Dynamic Display Pictograph technology, which is associated with Sentient Systems (www.sentient-sys.com). Both are symbol organizational systems used with sophisticated voice output communication aids (VOCAs) that allow the user to quickly locate the desired message among all the available messages. In simplest terms, Minspeak uses a single overlay in which a number of picture-covered buttons are located. By pressing a button or combinations of buttons, the desired message is activated. The pictures themselves are logically selected to act as cues to remind the user of the underlying message(s). One picture can represent more than one word or concept. For example, a picture of an apple can represent an apple, food in general, or red objects. If the user wants to say a certain food, then the apple is selected to represent food, followed by at least one other button to, then, indicate the specific food. In contrast, dynamic display systems are organized on a hierarchical basis, with each level of pictures increasing in specificity. Pressing a picture-button automatically displays only the set of pictures (i.e. categories or messages) that are under the category of the previous button. The first level of pictures, therefore, represent the largest themes. Pressing one of these picture-buttons automatically reveals the next logical set of pictures representing items in that theme. In this manner the user navigates down through automatically-appearing menus until the desired message is found. For example, pressing the picture-button that represents food may bring up a screen with pictures that represent breakfast foods, snacks, lunch food, etc. Pressing one of these buttons would then bring up the specific foods in that category. Today, the differences between Minspeak and DDP have lessened, in particular since the introduction of a device, the Vanguard by Prentke-Romich Co., that utilizes Minspeak in a DDP format (P. McNairn, personal communication, March 1, 1999). OTHER RESOURCES:
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Facilitated Communication Facilitated communication is a technique of AAC in which the adult acts as a direct intermediary for the child in communicating. In other words, the child guides the adult who then writes, types or uses an AAC device for the child. One example would be the child’s hand holding and guiding a partner’s hand as it types out a message on a computer, or points to pictures on a communication board. Training of the partner is essential since the partner must make sure that it is the child who is providing the direction, and not the adult. There has been a substantial amount of controversy regarding facilitated communication. The main dispute surrounds the extent to which the resulting messages are truly intended by the child, as opposed to subconsciously composed by the adult. The following articles, all from the August, 1994 issue of Mental Retardation provide an overview of the issues involved. They represent an attempt to present both sides of the facilitated communication debate.
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YAACK: AAC Connecting Young Kids Back to Top © YAACK 1999 |
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