Slide 6.1

Components of AAC Assistive Technology

From this point on, the content of the course will focus on high tech AAC systems. However, many principles covered will apply to the other unaided and aided areas of AAC systems.

The three general components of a high tech AAC system are:
1) language,
2) hardware,
3) selection methods
4) supports and services

1) and 2) are covered in this module.
3) and 4) are covered in the next module.

Don’t be confused about all the added options and features available on dedicated, integrated, and non-dedicated AAC systems. Your road map to success starts with a critical look at language. Consider the features first in terms of how it may improve performance and outcomes and result in the most effective communication. Although an AAC system may have options for listening to music, watching DVDs, or controlling other electronic appliances, the primary reason for using AAC is for interactive communication. Language makes that happen.

 

Language Requirements	Hardware	Selection Methods	Accessories and Services
• Single meaning pictures • Alphabet-based methods • Semantic compaction • Multiple methods	Control interface - Static - Touch Screen Grid-type pages Grid-type core/activity row Visual scenes -Hybrid Outputs -Speech/auditory -visual -electronic Data logging Memory capacity Portability	Direct selection -keyboard -headpointing Scanning -1-switch -2-switch -joystick Morse code	• Mounting systems • Carrying case • Peripherals (switches, headsticks, joystick) • Technical support • Training • Repair services • Warranties

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Slide 6.2

Language

The primary component of an AAC system is related to how language is represented and generated. All AAC systems use one or a combination of just three basic methods to represent language (Romich, Vanderheiden, & Hill, 2001).

The three (3) AAC language representation methods are:
• Alphabet-based methods,
• Single meaning pictures (symbols),
• Semantic compaction

As introduced in Module 2, achieving the goal of AAC and honoring the values expressed by people who rely on AAC requires being able to say what you want to say, when you want to say it, and saying it as fast as you can. The AAC language representation methods (LRMs) available on an AAC system directly influence achieving these values. AAC LRM availability influence spontaneous novel utterances generation (SNUG). This is the ability to put words together to build sentences that meet the specific need of the moment.

The intent of this course is not to provide thorough coverage of the AAC LRMs, but to introduce the reader to the importance of further learning on this component.

BECAUSE…

Language representation methods can be the single most important factor in determining communication performance.

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Slide 6.3

Alphabet-based methods

Alphabet-based methods are an easy concept to understand, since spelling with letter-by-letter selection is the basis of this method. This approach includes spelling, word and other prediction methods, abbreviation expansion, letter/word coding, and orthographic word selection (printed words on a display).

Since spelling letter-by-letter requires the most keystrokes and is a slow method to achieve SNUG, other strategies based on using the alphabet are used to:

1) reduce keystrokes, and
2) enhance communication rate.

Just because a strategy reduces the number of keystrokes needed to spell a word or sentence does NOT mean that communication rate will increase. Many research studies can be cited as evidence to show how communication rate is affected when keystrokes are reduced (Koester & Levine, 1994a; Koester & Levine, 1994b; Venkatagiri, 1994; Treviranus 7 Norris, 1987).

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Slide 6.4

Single meaning pictures (symbols)

With a single meaning picture approach to representing language in an AAC system, one picture means one word. The individual selects pictures (graphic symbols) and the AAC system converts the pictures into words. Each word in the vocabulary requires a picture.

= ball

= cup

An example of a single meaning picture system is the following 4 x 3 display using 12 graphic symbols.

Because single meaning picture symbols are seldom easy to identify if they do not represent a noun, the symbol is generally accompanied by the word being represented. Take a guess at the words (vocabulary) being illustrated on this AAC display. For the non-reader who cannot benefit from printed text, these many symbols representing common words or phrases cannot be guessed.

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Slide 6.5

Semantic Compaction™

Semantic compaction is the use of multi-meaning icons (symbols) in sequence to represent language (Baker, 1986). Semantic compaction is much more than sequences of icons that are combined to store words, phrases, or sentence messages in a Speech Generating Device (Beukelman & Mirenda, 2005, p. 72). Semantic compaction also involves a comprehensive (keyboard) display architecture along with patented features to provide access to the morphemes and linguistic structures of a language. Consequently, do not confuse “iconic encoding” for this language representation method – it is NOT an interchangeable term.

Basic Principle of Semantic Compaction

 

Remember, semantic compaction is the representation of vocabulary through sequences of multi-meaning icons. As shown in the above example, the “FROG” icon carries multiple meanings. The particular meaning is determined by the context in which the icon is used. When used with the “VERB” icon, the meaning is “go “. When used with the “RAINBOW” and “ADJECTIVE” icons, the meaning is “green “.

AAC systems using Semantic Compaction™ are available for Danish, French, German, Spanish, and are being developed for Chinese, Thai, and Japanese.

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Slide 6.6

AAC Language Application Software

Many AAC systems have one or more language programs installed for immediate use. Developers of AAC language application programs make decisions about the availability of the 3 AAC LRMS, the selection and organization of vocabulary for SNUG and use of pre-stored messages, and ability to use the grammar of a language. Some AAC language programs are designed for a specific population and stand alone. Other applications may have ranges or levels for various ages, abilities, or user populations.

Evaluating how language is represented and generated using an AAC system for SNUG should take into consideration the following factors:

1. Availability of the AAC language representation methods – Of the three (3) AAC LRMs which are available and how are the LRMs accessed?

2. Vocabulary/Message selection and organization – How high frequency of occurrence words are available and how the words are organized to select words to put together to make sentences. How pre-programmed messages are selected and organized to meet the need of a specific moment.

3. Access to use of the grammar structures of a language – How the person selects different forms of words, e.g. to make a plural form of a noun (dog = dogs) or the past tense of a verb (go = went).

4. Transition among levels of the language program – How much relearning is needed when a person changes to another level of the program as language needs grow, e.g. moving from 12 locations on a display to 24 locations on the display.

Because of the significance language plays in the design and selection of AAC technology, more comprehensive coverage of this topic is included in the courses titled:

Language-Based Approach to AAC Assessment and Intervention

AAC Symbols and Language Representation Methods

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Slide 6.7

Hardware

This slide begins the discussion on the hardware features of dedicated and non-dedicated AAC systems. You recall that, at this point, AAC devices may be referred to as VOCAs or SGDs. The major components that need to be considered when selecting or recommending an AAC system are:

• Control interface • Outputs • Data Logging • Memory • Portability

Throughout this module you will be asked to use the search engine of your choice to explore web sites to see examples of specific technology features and options. We feel this method will provide a fuller experience for seeing the variety of AAC system components and accessories on the market. In addition, this course is designed to teach the basic principles in identifying and evaluating AAC assistive technology components and not learning about specific AAC devices or AAC manufacturers.

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Slide 6.8

Non-Dedicated AAC Systems

A non-dedicated AAC system is typically a laptop computer with software and other modifications to provide the features that allow the hardware to function as an AAC system. A person can use a laptop computer as an AAC system, because an AAC language application has been installed. This being the case, the first consideration in using a non-dedicated AAC system is to evaluate the language software under consideration.

In addition, the purchaser has to be well aware that off-the-shelve hardware has not been designed for individuals with disabilities in mind. Issues of durability, mounting, power sources, access, and compatibility with other products to make the system function as an AAC device are frequently mentioned as obstacles to this approach. Individuals with changing needs over time have additional factors to consider when evaluating non-dedicated AAC systems.

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Slide 6.9

Control Interfaces for Dedicated Technology

The control interface refers to the type of display technology that supports the available Language application program(s). Today’s AAC system displays are classified as static, touch screen, or hybrid.

Static display interfaces: The typical example of a static display is the standard keyboard. An AAC system has a static selection area when the targets (letters or symbols) on an overlay do not change when an item is selected.

For example, the keys on a computer keyboard are static. Although the letters on a keyboard could be arranged using the standard QWERTY array or in alphabet order, once the keyboard is designed, the configuration does not change during use. This can be a significant advantage it terms of developing automatic use of the system – when you learn touch typing.

Take the time to do an image search on “alternative keyboards” using your favorite search engine to see examples of this control interface.

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Slide 6.10

Touch Screen Interfaces

Touch screens: The selection area of the touch screen display indicates the choices that can be made. The system recognizes when the display or monitor is being touched and takes appropriate action. The term dynamic display may be used to identify this type of control interface, because the display frequently changes with each selection. Touch screens offer much flexibility since they can be reconfigured depending on the software. Touch screens can be found in many locations in our communities such as the local ATM or check-out counter.

The language programs available using a touch screen interface can be identified based on the available LRMs and how vocabulary is organized on the display. Today, the following organization schemes are most typical:

• Grid-type single row: Words/Symbols are arranged on a touch screen with one row. The selection process either provides a spoken message or
navigates to other possible word/message options.

• Grid-type pages: Words/symbols are arranged in rows and columns on the display and the pages are identified according to the number of locations. For example: a page with 5 rows and 4 columns of symbols is a 20 location overlay or display; a display with 5 rows and 7 columns of symbols has a 45 location overlay. Representing a vocabulary of 1,000 words (typical of the normal 3 year old) requires 20 pages on a 50 location overlay.

• Grid-type core/activity row: Words/symbols are arranged in rows and columns on the display with dedicated rows for high frequency words and a dedicated row for words associated with specific topics, activities, social situations. This approach avoids the need for multiple pages, since symbols are sequenced to access words that occur frequently.

• Visual scenes: vocabulary is arranged as objects (pictures) embedded in a scene representing typical environments such as a kitchen, classroom, or store. The scenes are drawn so that the items in the environment are positioned over locations of a grid so when selected the word/message is spoken. The number of scenes and the number of “locations” available on a scene control the vocabulary/message size.

Feel free to visit sites of various AAC manufacturers to see if you can identify any touch screen systems and how the touch screen has been designed. Go to the ATIA (Assistive Technology Industry Association) member list to find AAC companies at http://www.atia.org/members.html.

Also, visit this web site for an example of how visual scenes are used in AAC: http://www.imakenews.com/aac-rerc/e_article000676427.cfm. Otherwise, use your favorite search engine to search the web for “Visual scenes in AAC.”

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Slide 6.11

Hybrid Displays

Hybrid interfaces: Hybrid systems have both a static selection area and a touch screen selection area. This provides the advantages of both. The static area is typically used for access to high frequency vocabulary and/or spelling. The touch screen selection area is used to access vocabulary using single meaning pictures, and word prediction.

In summary…

The type of array configuration should be recommended based on the comprehensive evaluation, because AAC teams need to consider the advantages and disadvantages of each alternative (Wilkinson & Jagaroo, 2004).

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Slide 6.12

Hardware – Outputs

The common outputs used in AAC technology are speech, visual, and electronic. Outputs provide specific functions and enhance interaction between the person and the AAC device, between the person and communication partners, and between the person and other technology (Hill, 2007).

AAC device outputs serve specific purposes. In addition to providing user feedback, speech and visual outputs can facilitate the use of the AAC device. For example, increase awareness that a key was selected or confirm that the right word was accessed on the display. Outputs, such as speech, are directed to a communication partner. However, electronic outputs can be used to interface with and provide control over other items, such as a television or computer.

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Slide 6.13

Speech/Auditory Output

For most high tech systems, the primary output is speech. Speech technology has two main approaches: digitized speech and synthetic speech.

Digitized speech is essentially an electronic recording. This means that the quality of the speech can be high, but the flexibility is low. Digitized speech systems can say only what has been pre-recorded.

Synthetic speech is generated using a computer program that changes text input into speech. This process is termed text-to-speech. This makes it very flexible, but the sound may not be as natural as digitized speech.

Some AAC systems offer both digitized and synthetic speech.

Voice banking is an approach that requires an individual to record their natural speech to preserve and save as a voice file. The voice file is later installed in an AAC system rather than using a standard, commercially-available synthetic speech voice. This approach is not widely availability, and is usually attempted with individuals with degenerative neurological disorders such as ALS.

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Slide 6.14

Outputs – Integrated AAC Systems

Other forms of output include infrared (IR), wired electronic (serial or USB ports), wireless electronic (Bluetooth, etc.), or printed.

Each has specific value. IR can be used for controlling other electronic items in the environment (TV, VCR, stereo, toys, etc.) or for wireless connection to a computer. Electronic outputs can be used for computer or printer connection or for wireless Internet access or telephone control. Some AAC systems have built-in printers.

Integrated AAC system refers a to high technology voice output device that provides additional or optional output methods (IR, Bluetooth) for computer access and/or non-communication functions. Consequently, a person can be carrying on a conversation about a favorite musician using an SGD (Speech Generating Device), and then use the SGD to turn up the volume on the CD player - a non-communication function.

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Slide 6.15

Data logging / Language Activity Monitor

Data logging is a feature that records the time and content of language events generated using the AAC system (Lesher, Moulton, Rinkus, & Higginbotham, 2000). Language Activity Monitoring (LAM) is the specific use of data logging to record and communication activity using an AAC system (Hill & Romich, 2001). LAM information provides quantitative data to for measuring communication performance. The following example shows the events that led to the utterance:

“It’s faster than spelling everything out which is what I used to do”.

16:26:05 SEM "It's " 16:26:08 SEM "faster " 16:26:14 SEM "than " 16:26:41 SPE "sp" 16:26:42 SPE "e" 16:26:45 SPE "l" 16:26:45 SPE "l"

16:26:46 SPE "i" 16:26:47 SPE "n" 16:26:48 SPE "g" 16:26:49 SPE " " 16:26:58 SEM "everything " 16:27:02 SEM "out " 16:27:05 SEM "which "

16:27:08 SEM "is " 16:27:11 SEM "what " 16:27:14 SEM "I " 16:27:19 SEM "used " 16:27:22 SEM "to do

LAM data provides for the identification of how the AAC LRMs are used for communication. The three letter mnemonic code indicates the LRM used to generate the event (SEM = semantic compaction; SPE = spelling).

LAM and/or Data logging supports evidence-based practice, which is the expected approach used for professional service delivery. However, early adopters and advocates of LAM were individuals who use AAC and their family members.

Since performance measurement is an expectation of today’s AAC service delivery, and use of LAM tools and resources provide an efficient approach to reporting performance, a comprehensive course an this topic is available titled:

AAC Performance Report: Definition, Generation, and Use

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Slide 6.16

Other Hardware Considerations

A variety of hardware components or features can be included on specification lists of AAC systems. Individuals evaluating and comparing AAC devices must be careful on how components are prioritized. Components or features that may be considered desirable should not have the same weight or value. Language is always the highest priority. Other components and features become insignificant or useless if the person cannot use the AAC system to talk. Don’t be swayed away from the goal of AAC; by considerations that won’t positively impact communication performance. If sacrifices must be made, sacrifice that which will not compromise the most effective communication.

Consider the priority that should be placed on the memory capacity of an AAC system and the weight and size of the AAC system.

Memory capacity: Computer-based AAC systems run on an operational system or platform. For the most part, memory capacity is in constant change as AAC manufacturers upgrade systems, and is a function of the latest updating. To be protected, any consideration of purchasing an AAC system requires a trial to ensure that the system functions properly, runs the desired language applications, and performs any additional operations identified as important.

Portability: The weight and size of the AAC device generally becomes a consideration when an individual is walking independently or for appearance. Unfortunately, many people realize too late that by selecting the most portable AAC device the communication potential was significantly reduced. In addition, access became difficult, and the person was able to rely on unaided or low technology options in the environments that the portable AAC device once was considered necessary. Adults with degenerative neurological disorder such as ALS may find a highly portable AAC SGD desirable when they are able to walk and access a small keyboard or small display using a stylus. However, as skills deteriorate and language needs increase, portability is no longer a priority. In most situations, funding sources will only purchase one device or will not fund another device for a period of several years.

End of Module 6