Jump to content

Augmentative and alternative communication

From Wikipedia, the free encyclopedia
This is an old revision of this page, as edited by Pam pull MOOSE (talk | contribs) at 21:08, 29 March 2009 (→Rate enhancement strategies). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Augmentative and alternative communication (AAC) is communication for those with impairments or restrictions on the production or comprehension of spoken or written language.[1]

Aided and Unaided AAC

AAC is used by individuals with communication disorders for whom speech is temporarily or permanently inadequate to meet all or some of their communication needs. Speech may be replaced or augmented by using a variety of modes including body language, gesture, vocalizations, manual sign, writing and/or augmentative communication aids.

Aided AAC

An AAC aid is any "device, either electronic or non-electronic, that is used to transmit or receive messages".[2] The skills, areas of difficulty and communication requirements vary greatly within the AAC user community, and so an equally diverse range of communication aids exists to meet these demands.

Low Tech

Low-tech communication aids are those which do not need batteries or electricity to meet the user's communication needs.[3] These are often very simple aids created by placing phrases letters, pictures or symbols on a board or in a book. Depending on a person's physical abilities and limitations, the user accesses the device by pointing to the appropriate message with their fingers, a non-electronic pointer, such as a head or mouth stick or by eye gaze.[3]

Low-tech aids are limited in terms of the amount of messages they can convey: Only so many messages can fit on a single low-tech communication board or communication book. In comparison, natural speech can convey infinite messages, and many high-tech aids are only limited in terms of their memory store and battery life. Non-lexical linguistic systems based on semantics (i.e Blissymbols ) are purported to transcend this limitation. [citation needed]

High Tech

High-tech AAC aids are electronic devices that permit the user to communicate with others by producing digitized or synthesized speech or by typing out messages.[3][4] These devices can also be referred to as Speech Generating Devices (SGDs) or Voice Output Communication Aids (VOCAs).[3] A diverse array of such electronic devices is presently available and each user is matched with the device that is most suitable for their needs and skills. Some devices can be simple electronic communication boards that produce the word, phrase or a story stored under chosen symbols. Other devices can say the words or the letters that are typed by the user.[3] The more sophisticated electronic AAC devices consist of communication software installed on fully functional computers which are adapted to the users' physical capabilities. The users can then switch from the communication program to general operating system and use their device to access internet, email, games, word processors and other standard computer software.[citation needed]

High-tech devices vary in price, size, and amount of information they can store. In terms of portability, some devices are smaller and lighter than others and many devices can be mounted to a wheelchair if necessary. There is usually more than one way to access the devices, depending on the physical capabilities of the user. They can be operated using touch screens, switches, joysticks, head-operated mouses or programs which track the eye gaze of the user.[4]

Continuous advancement and new development of high-tech communication devices is highly important for improving the communication abilities of people who do not use natural speech. Electronic devices operate on batteries which need to be frequently changed or charged. Moreover, in the event that a device stops working, the user should have access to a low-tech device until the electronic one is fixed.[3]

Unaided AAC

Unaided AAC includes sign language and gesture systems, as well as body language.

Symbols

Some people who use AAC can read and spell; others cannot, and need communication aids on which language elements are represented by pictures or graphic symbols such as Picture Exchange Communication System (PECS). Symbols are also used within a complete linguistic system in Blissymbols.[citation needed]

Organization of symbols

Dynamic versus Static Display
In static display all the icons are fixed in a matrix form and are visible on the device. The advantage of this display is the fact that the user can see all the available icons during the scan. The dynamic display shows only portions of the icons depending on the chosen category. The advantage of the dynamic display is the reduced amount of information that needs to be scanned, which in turn increases the communication rate of the user. Research has shown that devices with static display can be used with young children while the dynamic displays should be introduced once children have mastered abstract vocabulary and categorical organization.[5].

Access

Traditional communication is accessed through the mouth (by speaking), the ears (by hearing), the eyes (by seeing) and the brain (by appropriately processing meaning). People with impairments to any of these organs may require augmented or alternative access to communication.

Some people with severe communication impairments can use their hands; others cannot, and have to use alternatives, such as mouth sticks, headsticks, switches or eye-pointing.

  • Direct Selection: An individual points to the desired symbol using a finger or alternative selection technique (i.e., headpointer or eyegaze pointing).
  • Scanning: An individual is offered an array of symbols. As the communication system or partner scans through the symbols, the AAC user indicates his/her desired choice by using the alternative selection technique (i.e.switch access, head nodding) to select the desired symbol.[citation needed] User's visual acuity and visual-perceptual discrimination skills will affect the presentation of the symbol system (e.g. size of the graphic symbols and background-figure contrast) on the AAC device. [6]

Rate enhancement strategies

AAC communication is generally slower than speech.[7] Rate enhancement strategies increase the rate of communication output of the user and as a result enhance the efficiency of communication. There are two main options for increasing the rate of communication for AAC devices: encoding and prediction.[7]

  • Encoding is the way a user is able to produce messages using the device. If an entire word, phrase or sentence can be retrieved with a one or two symbol or letter code, communication will occur faster.[7]
  • Iconic Encoding uses pictures, line drawings, or shapes to represent frequently used concepts. This is especially useful for non-literate users, as it gives them access to large vocabularies while requiring fewer keystrokes and minimal spelling or reading abilities. For example, a picture of a toilet may represent “I need to use the bathroom”.[8]
  • Semantic Compaction (Minspeak) uses icons with multiple meanings which are sequenced together. The meaning of the message is then dependent upon each icon in a particular sequence. For example, typing “food + yellow + B” may represent “banana”.[8][9]
  • Letter Encoding/Abbreviation-Expansion stores words, phrases or sentences as abbreviations, which eliminates having to type complete words or phrases. For example, typing “HH” may represent the greeting, “Hello, how are you?”.[9]
  • Alpha-numeric/Numeric Encoding stores messages under combinations of letters and/or numbers. For example, typing “G1” may represent "Greeting 1", producing "Hello, how are you?”.[8]
  • Prediction refers to the ability of the device to guess the word that is being typed by the user and to provide choices in message output. When the prediction is correct, the user selects it and no longer has to type the entire word. The user is also provided with additional choices to select in case the initial guess is incorrect. The word prediction software may determine the possible choices offered based on frequency in language, word association, past choices, or grammatical suitability.[7][9]
  • Word Completion allows the device to predict the end of a word based on the first letters typed and a menu of likely words is offered based on the user’s initial keystrokes. If the desired word is offered, the user can select it without the need to continue typing the rest of the word. For example, if the user types “h-e”, “hello" or "help” may be offered as choices to complete the word.[7][8][9]
  • Next Word Prediction allows the device to predict words based on word pairings and/or grammatical rules of the words occurring before it. For example, if the user types, “I am”, the device may offer typical responses to this sequence of words such as “going", "feeling".[7]
  • Linguistic Prediction lets the device offer words that agree in tense, case and number based on previous words in the message. For example, if the user has typed “tomorrow”, only words in the future tense will be offered as choices.[7]

Team

A comprehensive evaluation of a user's unique abilities and requirements is necessary in order to implement appropriate intervention and match the user with the most appropriate AAC device. AAC evaluations are conducted by specialized multidisciplinary teams consisting of a speech-language pathologist, occupational therapist, physiotherapist, social worker and a physician.[10][6] The assessment team conducts interviews with the user, family members, caregivers and/or teachers in order to obtain additional information about the user's behaviour and skills in different settings. The team also assesess the user's motor abilities, communication skills, cognition and vision.[10]

During the intervention process the occupational therapist assists with the positioning and seating adaptations for convenient AAC access. The physiotherapist works on motor development training. The speech-language pathologist's role is to teach the user and their communication partners how to use the AAC device, encouraging the use of natural speech when possible. In selecting and adapting the AAC device for the user's individual needs, the speech-language pathologist must ensure that the AAC device can be used in different contexts with different communication partners. [6]

Specific groups of AAC users

Whenever possible, AAC devices should be designed for Dynamic Diversity [11], where the interface is accessible not only to “typical” AAC users, but also to minority populations who need to use the device.

Cerebral Palsy

The motor deficits associated with cerebral palsy (CP) cause speech disorders in 31% to 88% of CP patients. AAC practitioners seek to prevent the development of learned helplessness in children with cerebral palsy, as these children tend to be passive communicators.[6]Family members and peers may tend to direct and control conversations, and consequently, children with CP may not use their AAC aids to develop conversations by initiating or taking the lead in conversation, using complex syntax, asking questions, making commands, or adding new information. Such interaction patterns could result in a failure to develop the full range of communicative skills. [12][13]
Early intervention with the speech language pathologist can target situations which teach children with CP how to develop their conversational skills, how to effectively communicate with others, and how to control their environment through communication. Children with cerebral palsy are encouraged to practice using their AAC system for making choices, decisions and mistakes. [6]

Developmental dyspraxia

Developmental dyspraxia is a childhood motor speech disorder involving impairments in the motor control of speech production, typically causing impairments in motor programming and execution. Major symptoms include difficulties with speech imitation, a reduced ability to produce rapid, repeated oral movements, problems initiating movements for speech, as well as difficulties producing sounds in sequence.[14]

The speech of children with developmental dyspraxia may be unintelligible to the point that daily communication needs cannot be met and that the child experiences great amounts of frustration. In such cases, AAC becomes an option to consider. AAC can be seen as a secondary strategy to support successful communication attempts in these children, with the hope that speech will improve with time and one day be able to meet daily communication needs. Research indicates that AAC use with these children does not decrease speech skills significantly, and that it may improve it with time.[15] Nonetheless, when AAC is selected as part of intervention for a child with developmental dyspraxia, many clinicians will choose to continue working on improving natural speech production as well.[15]

A wide variety of AAC systems have been used with children with developmental dyspraxia.[16] Manual signs or gestures is the most frequently seen unaided AAC system introduced to these children, and can include signing unintelligible target phonemes (using fingerspelling) in concert with speech. Articulation and sequencing errors in speech has been shown to decrease in these children with the use of manual signs.[15] While advantages of this system include its portability and unlimited vocabulary potential, disadvantages include potential problems with fine and gross motor skills, as well as the fact that most of the people these children will be interacting with will not be able to understand the signs being produced.[16] With familiar communication partners, total communication approaches may be beneficial for these children, such that signs and words are used simultaneously.[15] With total communication, the child has the ability to be understood through sign, while continuing to attempt to successfully produce speech.

The main aided systems used with children with developmental dyspraxia include picture symbol communication boards or books, and voice output devices.[16] While communication boards (or books) are portable and can be tailored to meet the needs of various communicative contexts, they present the user with the limited ability to communicate about topics made available by the board.[17] Voice output devices provide the user with a much greater vocabulary and ability to converse about a wider range of topics. In addition, they allow the user to generate grammatical sentences, rather than pointing to single pictures at a time.[15]

A multimodal approach is often chosen, such that more than one AAC option is introduced to the child. This way, the child is not only given the opportunity to experiment with various AAC systems (aided and unaided), but can also take advantage of the fact that certain options may be better than others in certain contexts.[15] For example, voice output devices may work well during dinner, but the child may need to make use of manual signs while in the bath.

Visual impairment

It is sometimes possible to adapt high and low tech AAC devices in order to make them accessible to AAC users who are blind or who have visual impairments.

  • Modified visual output includes large print and/or clear simple graphics, and can be of benefit to AAC users with some residual vision.[11]
  • Tactile/tangible symbols are textured objects, real objects or parts of real objects which may be included on an AAC device for individuals with visual impairment. [18] Braille is an example of a tactile/tangible reading and writing system. Tactile/tangible symbols should be considered meaningful to the AAC user, thus allowing them access to language. They can be used on low or high tech displays and switches. A limitation of using tactile/tangible symbols is that they may decrease the number of symbols available to the AAC user at one time.
  • Auditory symbols are those which produce a meaningful sound when activated, and are thus useful for AAC users who have vision impairments. Morse Code is an example of an auditory symbol system, where long and short tones represent letters, words, and phrases. There are some AAC devices that can convert Morse code into text or speech.[citation needed] Speech is another example of an auditory symbol which can be integrated with assistive technology for the blind and visually impaired.[18]
  • Auditory scanning is an access method which presents options to the user by pronouncing them out loud. Users then select the desired option upon hearing it. This can be helpful for users who are unable to scan options presented visually.[19]

Amyotrophic lateral sclerosis

Amyotrophic Lateral Sclerosis (ALS) is a progressive condition whereby the motor neurons required for smooth, voluntary movements slowly breakdown, leading to weakness and eventual paralysis. Approximately 75% of people with ALS become unable to speak before the time of their death.[20]

When to consider AAC: Given the rapid progession of the disease, those diagnosed with ALS should be provided with information about various AAC options as early as possible in order to acclimatize to the device before it replaces natural speech.[21] Generally, AAC will be necessary when speech intelligibility becomes inconsistent, especially in adverse listening conditions (i.e.: noisy restaurant).[20] In most cases, this happens when speaking rate drops to 100 words per minute.[22] The use of AAC does not have to be an “all-or-nothing” situation. In the early stages of ALS, AAC may only be necessary to augment speech with unfamiliar partners (for example: using an alphabet board to cue the listener to the first letter of the word being spoken). In the later stages of ALS, AAC may become the main communicative method, while familiar conversation partners may still be aware of a limited amount of speech.[21] ALS is degenerative in nature, and the choice of device should take both present and future needs under consideration. It may be more convenient to choose a device that can be altered to accommodate the changing motor abilities of the individual, rather than changing the device as the disease progresses.[20]

Types of AAC for ALS: In general terms, the ideal AAC device will depend on severity of speech impairment, functional status and communication needs in particular environments.[21] Lifestyle also needs to be considered. If working outside of the home, portability, durability and powered mobility will be crucial considerations.[23] If spending most time in a home with numerous floors, noisy children or pets, etc., considerations about amplification will be important.[24] With cognition and vision unaffected, either writing or typing is ideal because they allow unlimited expression.[21] The challenge is then to find the best means to spell out the messages.

  • Spinal form of ALS: As limbs are affected from the onset of the disease, high-tech devices are often most helpful as they can be modified to accommodate physical impairments through head or eye tracking (see above).[25] Low-tech systems such as eye gazing or partner assisted scanning should also be considered for situations when electronic devices are unavailable (i.e.: during bathing).[21]
  • Bulbar form of ALS: As speech is affected well before limbs, handwriting is often the first course of AAC. As the disease progresses and starts affecting hand movement, writing or typing VOCA devices may be suggested as these require less dexterity while still offering full freedom of expression. In the final stages of the disease, eye gazing and partner assisted scanning may be used, and carry the added benefit of promoting social closeness.[21]

Terminology Used in AAC

Symbol: Something used to represent another thing or concept. For example, a picture or line drawing of a dog to represent dog.

Symbol Set: A set of symbol that is closed in nature; symbol set can be expanded, but it does not have clearly defined rules for expansion (e.g., Picture communication symbols).

Symbol System: A set of symbol; includes rules or a logic for the development of symbols (e.g., Blissymbols).

Speech Generating Device: An electronic assistive device that produces speech (e.g., Dynavox, Mercury).

VOCA: Voice Output Communication Aid; other term for electronic assistive device producing speech

Assistive Communication Device: Electronic or non-electronic assistive technology device that provides external assistance for communication.

AAC System: An integrated network of symbols, techniques, aids, strategies, and skills.

Input Method: Technique used to select representations of the wanted utterances from an electronic device (e.g., touchscreen selection, eyegaze pointing, switch access)

Tangible Symbols: Tangible symbols are objects or pictures that are used as symbols by individuals who are not able to communicate using more conventional symbol systems. Tangible symbols bear an obvious and concrete relationship to the visual or tactile properties of the entities that they represent. They are a type of “augmentative and alternative communication” (AAC).

See also: Blissymbolics


User's Experience with AAC

When adults with CP and complex communication needs enter hospitals, they are often faced with communication difficulties with hospital staffs. In a hospital setting, the communication barriers are: not having a way to communicate (e.g. bed-ridden, can't access the AAC, or the AAC is not in the hospital), not having the opportunity to communicate (e.g. perceived as time consuming to communicate with a patient with AAC), lack of understanding by hospital staffs of the patient's communicative attempts and not responding to these attempts[26]. Family members tend to take over and speak on behalf of the patient to the doctors and nurses. In one study where adults with CP were interviewed, they expressed that doctors were too busy and since patients needed time to communicate using AAC, doctors would speak to the family instead. One patient recounted a successful story where his brother taught the nurse how the patient communicates with the AAC and then the patient used the AAC to communicate with the nurse directly[27]. The implication of this scenario is that communication is possible as long as hospital staffs are aware of other communication modes (AAC), family members are willing to be less-protective and patients are confident enough to speak for themselves. The consensus of these interviews is that adults with CP wish to be treated like adults in hospital and they would like to be involved in decision making about their health care. They also want to be involved in the education of hospital staffs about AAC communication. Cite error: The opening <ref> tag is malformed or has a bad name (see the help page). Doctors and nurses need to become familiar with AAC systems and have some knowledge/skills on how to interact with patients with complex communication needs. [28].

References

  1. ^ "Roles and Responsibilities of Speech-Language Pathologists With Respect to Augmentative and Alternative Communication: Position Statement". www.asha.org. 2005. Retrieved 2009-01-23.
  2. ^ Beukelman, D.R., and Mirenda, P: Augmentative & Alternative Communication, page 4. Paul H Brookes Publishing Co., 2005
  3. ^ a b c d e f Technology. International Society for Augmentative and Alternative Communication. Retrieved on March 19 2009.
  4. ^ a b Connections. Learning Independence through Computers Inc. Retrieved on March 20 2009.
  5. ^ Hochstein, David D. (2004). "Recognition of Vocabulary in Children and Adolescence with Cerebral Palsy". Augmentative and Alternative Communication. 20 (2): 45–62. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  6. ^ a b c d e Beukelman, David R. (1999). Augmentative and Alternative Communication: Management of severe communication disorders in children and adults. Pat (2 ed.). Baltimore: Paul H Brookes Publishing Co. pp. 246–249. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  7. ^ a b c d e f g Rate Enhancement. Augmentative and Alternative Communication at the University of Washington, Seattle. Retrieved on March 19 2009.
  8. ^ a b c d Venkatagiri, H. (1995). "Techniques for Enhancing Communication Productivity in AAC: A Review of Research". American Journal of Speech-Language Pathology, 4:36-45
  9. ^ a b c d Types of AAC Devices. Augmentative Communication, Incorporated. Retrieved on March 19 2009.
  10. ^ a b Mineo, Beth (1990). "Augmentative and alternative communication: Tech Use guide. Using computer technology". US department of Education. {{cite journal}}: Cite journal requires |journal= (help)
  11. ^ a b Gregor, P., Newell, A.F., Zajicek, M. (2002). Designing for Dynamic Diversity – interfaces for older people. Proceedings of the fifth international ACM conference on Assistive technologies. Edinburgh, Scotland. Session: Solutions for aging. Pages 151-156.
  12. ^ Pennington, Lindsay (2001). "Predicting patterns of Interaction between Children with Cerebral Palsy and their Mothers". Developmental Medicine & Child Neurology. 43: 83–90. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  13. ^ CLARKE, Michael (December, 2007). "Interaction between Children with Cerebral Palsy and their Peers". Augmentative and Alternative Communication. 23 (4): 336–348. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  14. ^ Bornman, J (2001). "The use of a digital voice output device to facilitate language development in a child with developmental apraxia of speech: a case study". Disability and Rehabilitation. 23 (14): 623–634. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  15. ^ a b c d e f Beukelman, David (2005). Augmentative & Alternative Communication (3 ed.). Baltimore: P.H. Brookes. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  16. ^ a b c Weitz, Cynthia. "AAC and Children With Developmental Disabilities". The Handbook of Augmentative and Alternative Communication. pp. 395–405. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  17. ^ Cumley, Gary (1999). "Augmentative and Alternative Communication Options for Children with Developmental Apraxia of Speech: Three Case Studies". Augmentative and Alternative Communication. 15: 110–125. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  18. ^ a b Beukelman, D., Mirenda, P., Franklin, K. & Newman, K. (1992). Persons with visual and dual sensory impairments. In D. Beukelman & P. Mirenda, Augmentative and alternative communication: Management of severe communication disorders in children and adults. Baltimore: Brookes, 291-309.
  19. ^ McAfoose, L. (2002). Introduction to Auditory Scanning. Building Blocks by DynaVox Systems LLC, 1. Pages 1-37
  20. ^ a b c Doyle, M. (2001). "Trends in augmentative and alternative communication use by individuals with amyotrophic lateral sclerosis". Augmentative and Alternative Communication. 17 (3): 167–178. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  21. ^ a b c d e f Beukelman, D. (1998). Augmentative & Alternative Communication: management of severe communication disorders in children and adults (2 ed.). Baltimore: P.H. Brookes Pub. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  22. ^ Duffy, J. (2005). Motor Speech Disorders: Substrates, Differential Diagnosis and Management (2 ed.). Rochester, Minnesota: Elsevier Mosby.
  23. ^ Beukelman, D. (1998). Augmentative & Alternative Communication: management of severe communication disorders in children and adults (2 ed.). Baltimore: P.H. Brookes Pub. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  24. ^ Beukelman, D. (1998). Augmentative & Alternative Communication: management of severe communication disorders in children and adults (2 ed.). Baltimore: P.H. Brookes Pub. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  25. ^ Mathy (2000). "Augmentative Communication for Individuals with Amyotrophic Lateral Sclerosis". In Beukelman, Yorkston, Reichle (ed.). Augmentative and Alternative Communication Disorders for Adults with Acquired Neurologic Disorders. Baltimore: P.H. Brookes Pub. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)CS1 maint: multiple names: editors list (link)
  26. ^ Balandin, Susan (2007). "Communicating with nurses: The experiences of 10 adults with cerebral palsy and complex communication needs". Applied Nursing Research. 20: 56–62. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  27. ^ HEMSLEY, BRONWYN (2008). "'We need to be the centrepiece': Adults with cerebral palsy and complex communication needs discuss the roles and needs of family carers in hospitals". Disability and Rehabilitation. 30 (23): 1759–1771. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  28. ^ Balandin, Susan (2007). "Communicating with nurses: The experiences of 10 adults with cerebral palsy and complex communication needs". Applied Nursing Research. 20: 56–62. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

Works Cited

Retrieved from "https://en.wikipedia.org/w/index.php?title=Augmentative_and_alternative_communication&oldid=280498683"