Augmentative and alternative communication
Encyclopedia
Augmentative and alternative communication (AAC) is an umbrella term
that encompasses the communication methods used to supplement or replace speech or writing for those with impairments in the production or comprehension of spoken or written language. AAC is used by those with a wide range of speech and language impairment
s, including congenital impairments such as cerebral palsy
, intellectual impairment and autism
, and acquired conditions such as amyotrophic lateral sclerosis
and Parkinson's disease
. AAC can be a permanent addition to a person's communication or a temporary aid.
Modern use of AAC began in the 1950s with systems for those who had lost the ability to speak following surgical procedures. During the 1960s and 1970s, spurred by an increasing commitment in the West towards the inclusion
of disabled individuals in mainstream society and developing the skills required for independence, the use of manual sign language
and then graphic symbol communication grew greatly. It was not until the 1980s that AAC began to emerge as a field in its own right. Rapid progress in technology, including microcomputers and speech synthesis
, have paved the way for communication devices with speech output and multiple options for access to communication for those with physical disabilities
.
AAC systems are extremely diverse: unaided communication uses no equipment and includes signing and body language
, while aided approaches use external tools and range from pictures and communication boards to speech generating devices. The symbols used in AAC include gestures, photographs, pictures, line drawings, letters and words, which can be used alone or in combination. Body parts, pointers, adapted mice, or eye tracking
can be used to select target symbols directly, and switch access scanning
is often used for indirect selection. Message generation is generally much slower than spoken communication, and as a result rate enhancement techniques may be used to reduce the number of selections required. These techniques include "prediction", in which the user is offered guesses of the word/phrase being composed, and "encoding", in which longer messages are retrieved using a prestored code.
The evaluation of a user's abilities and requirements for AAC will include the individual's motor, visual, cognitive, language and communication strengths and weaknesses. The evaluation requires the input of family members, particularly for early intervention. Respecting ethnicity and family beliefs are key to a family-centered
and ethnically competent approach. Studies show that AAC use does not impede the development of speech, and may result in a modest increase in speech production. Users who have grown up with AAC report satisfying relationships and life activities; however, they may have poor literacy and are unlikely to be in employment.
data vary depending on the country and age/disabilities surveyed, but typically between 0.1 to 1.5% of the population are considered to have such severe speech-language impairments that they have difficulty making themselves understood, and thus could benefit from AAC. An estimated 0.05% of children and young people require high technology AAC. Well-known AAC users include physicist Stephen Hawking
, broadcaster Roger Ebert
and poet Christopher Nolan
. Award-winning films such as My Left Foot
and The Diving Bell and the Butterfly
, based on books by AAC users Christy Brown
and Jean-Dominique Bauby
respectively, have brought the lives of those who use AAC to a wider audience.
The field was originally called "Augmentative Communication"; the term served to indicate that such communication systems were to supplement natural speech rather than to replace it. The addition of "alternative" followed later, when it became clear that for some individuals non-speech systems were their only means of communication. AAC users typically utilize a variety of aided and unaided communication strategies depending on the communication partners and the context.
, and has been used with children with severe-profound disabilities, and adults with a variety of diagnoses including dementia
, aphasia
and dysarthria
. The benefits of gestures and pantomime are that they are always available to the user, usually understood by an educated listener, and are efficient means of communicating.
In contrast, sign languages have a linguistic base and permit the expression of an unlimited number of messages. Approaches to signing can be divided into two major categories, those that encode an existing language, and those that are languages in their own right. Signing Exact English
may be considered the most widely used example of the former and American Sign Language
as a common example of the latter. Signing is used alone or in conjunction with speech to support communication with individuals with a variety of disorders. The specific hand shapes and movements of sign and gesture require an individual to have adequate fine motor and motor planning skills. Sign languages require more fine-motor coordination and are less transparent
in meaning than gestural codes such as Amer-Ind; the latter limits the number of people able to understand the person's communication without training.
uses text-to-speech software that can be harder to understand but that permits the user to spell words and speak novel messages.
High-tech systems may be dedicated devices developed solely for AAC, or non-dedicated devices such as computers that run additional software to allow them to function as AAC devices. They may be static or dynamic in form. Static communication devices have symbols in fixed positions on paper overlays, which are changed manually. To increase the vocabulary available, some static devices have multiple levels, with different words appearing on different levels. On dynamic AAC devices, the user can change the symbols available using page links to navigate to appropriate pages of vocabulary and messages.
High-tech devices vary in the amount of information that they can store, as well as their size, weight and thus their portability. Access methods depend on the abilities of the user, and may include the use of direct selection of symbols on the screen or keyboard with a body part, pointer, adapted mice
or joysticks, or indirect selection using switches and scanning. Devices with voice output offer its user the advantage of more communicative power, including the ability to initiate conversation with communication partners who are at a distance. However, they typically require programming, and tend to be unreliable. Because of the latter, low tech systems often recommended as a backup in case of device failure.
For users with literacy skills, both low and high-tech devices may use alphabet-based symbols including individual letters, whole words, or parts thereof. With low-tech devices, the communication partner must interpret the symbols chosen whereas a high-tech device can speak the created message aloud. Several large graphic symbol sets have been developed; these include Blissymbols
, which possess linguistic characteristics such as grammatical indicators, and the more iconic Picture Communication Symbols
(PCS) which do not.
Tactile symbols
are textured objects, real objects or parts of real objects that are used as a communication symbols particularly for individuals with visual impairment
s and/or significant intellectual impairments.
Auditory symbols such as choices of spoken words or Morse code
can also be integrated with assistive technology for the visually impaired.
The choice of symbols and aspects of their presentation, such as size and background, depend on an individual's preferences as well as their linguistic, visual, and cognitive skills.
In "Direct Selection", the selection is made by pointing to the desired symbol using a finger or an alternative pointer, such as eye gaze, a head stick, head- or eye-controlled mouse. To accommodate motor control difficulties some users use alternative activation strategies; for example in "timed activation", the user maintains selection of the symbol for a predetermined period of time until it is recognized by the system. With the "release activation", the selection of the item is only made when the person releases contact from the display.
Direct activation of an AAC system is generally the first choice of access method as it is faster and cognitively easier. Those unable to do so may use indirect selection or "scanning". In this method, items displayed for selection are scanned; the scanning may be visual using indicators such as lights, highlighting, and/or contrasting borders, or auditory using spoken prompts from a communication partner or device. When the desired message is reached, the AAC user indicates the choice using an alternative selection technique such as a switch
, vocalization or gesture. Several different patterns for switch access scanning
are available: in "circular scanning", the items are displayed in a circle and then scanned one at a time. It is often introduced first to children or beginning AAC users because it is the easiest to understand. In "linear scanning", items are organized in rows and are scanned one at a time until a choice is made. Although more demanding than circular scanning, it is still easy to learn. Finally, in "group-item scanning", items are grouped and the groups scanned consecutively. Once a particular group is selected, items within the group are scanned. One of the most common group-item strategies is row-column scanning in which each row forms a group. The rows of items are scanned and when a row is selected, the items in the row are scanned one at a time until a message is selected.
There are three main selection control techniques in scanning. In "automatic scanning", the scan proceeds at a pre-determined speed and pattern until the user selects an item. In "inverse scanning", the switch is held down to advance the scan, and released to choose the desired iem. In "step scanning", the AAC user activates one switch to move the indicator through the items, and another switch to select the item.
Communication books and devices are often presented in a grid format; the vocabulary items displayed within them may be organized by spoken word order, frequency of usage or category. In the Fitzgerald Key organization, symbols from different semantic and syntactic classes are organized in groups from left to right to facilitate sentence construction. Since research has shown that children and adults use a small number of words frequently, in a core-fringe vocabulary organization, the words and messages that are communicated most frequently appear on a "main page". The fringe vocabulary—words and messages used more rarely and that are specific to an individual—appear on other pages. Symbols may also be organized by category, grouping people, places, feelings, foods, drinks, and action words together. Another form of grid organization groups vocabulary according to specific activities. Each display contains symbols for the people, places, objects, feelings, actions, and other relevant vocabulary items for a specific activity or routine.
Visual scene displays are a different method of organizing and presenting symbols. These are depictions of events, people, objects, and related actions in a picture, photograph, or virtual environment representing a situation, place, or specific experience. They are similar to activity displays in that they contain vocabulary that is associated with specific activities or routines. For example, a photo of a child's room may be included in the child's AAC system. Objects and events within the photograph are then used as symbols for communication. Research suggests that visual scene displays are easier than grid displays for young children or those with cognitive impairments to learn and use.
A bottleneck in High-tech AAC is that users must program new utterances manually (e.g. names of new friends). Research approaches attempting to overcome this bottleneck range from generating content based on a log of conversation with a user's friends and family, to data mined from the internet for language materials, By accessing more of a user's data, more high-quality messages can be generated at a risk of exposing sensitive user data For example, by making use of global positioning systems, a device's content can be changed based on geographical location. Moreover, by making use of Lifelog
ging based approaches, a device's content can be changed based on events that occur to a user during their day.
Encoding is a technique permitting an AAC user to produce an entire word, sentence or phrase using only one or two activations of their AAC system. In numeric, alpha-numeric, and letter encoding (also known as abbreviation-expansion), words and sentences are coded as sequences of letters and numbers. For example, typing "HH" may retrieve "Hello, how are you?". In iconic encoding strategies, such as Semantic compaction
, icons (picture symbols) are combined in a sequence to produce words or phrases.
Prediction is a rate enhancement strategy in which the device attempts to predict the letter, word or phrase being written by the user. The user can then select the correct prediction without needing to write the full word. Word prediction
software may determine the words predicted based on their frequency in language, association with other words, past choices of the user, or grammatical suitability.
, rehabilitation engineer, physiotherapist, social worker and a physician
. Users, family members and teachers are also key members of the decision making team. Sensitivity to and respect of cultural diversity
contributes to ongoing family involvement and to the selection of the most appropriate AAC system. For members of some cultural groups the presence of an AAC device increases the visibility of disability and is thus viewed as stigmatizing.
A user's motor abilities, communication skills and needs, cognition
and vision are assessed in order to determine the most appropriate match to a communication system. Depending on the individual's physical status, recommendations of an alternative access method, a change in seating/positioning, a mounting system and/or communication aid adaptations may be needed. For example, someone with spastic
arm movements may require a key guard on top of the keyboard or touchscreen
to reduce the selection of non-target items. The person's needs and abilities determine the symbols chosen and their organization, with the goal being that the communication system can be used as efficiently as possible in different contexts, with different communication partners, and for different social purposes. Researcher Janice Light identified four social purposes of communicative interaction in AAC: the expression of needs and wants to a listener, the transfer of information as in more general conversation, the development of social closeness through such things as jokes and cheering, and finally social etiquette practices such as "please" and "thank you". These four purposes vary in terms of the relative importance of the content, rate, duration and the focus of the interaction. It is important that the AAC systems selected also reflect the priorities of the individual and their family. In Western cultures, professionals may see a communication device as helping to promote an individual's self-determination
, i.e., the ability to make one's own decisions and choices. However, cultural and religious factors may affect the degree to which individual autonomy is a valued construct, and influence family attitudes towards AAC.
Training can help the user make use of their AAC system to communicate effectively with others, to control their environment through communication, and to make choices, decisions and mistakes. Skilled users of AAC show communicative competence
in four interrelated areas: linguistic, operational, social and strategic. Linguistic competence
refers to language skills in the person's native language as well as the linguistic code of the symbol system selected. Operational competence involves the skills in the use and maintenance of the tool of communication, while social competence
and strategic competence reflect knowledge and judgment in communicative interactions, including the compensations required for a slow speaking rate, communication breakdowns and those unfamiliar with AAC. An AAC user may require specific device programming and/or training to achieve competency in these areas.
Communication partners may also require training to notice and consistently interpret the communication signals of a severely disabled individual, particularly because there is a danger that learned helplessness
can be the result of repeated failure to communicate successfully. Parties may need assistance to avoid the directive communication style that can lead a child user of AAC not to develop a full range of communication skills such as initiating or taking the lead in conversation, using complex syntax, asking questions, making commands or adding new information.
Young AAC users benefit from rich language and literacy experiences to foster vocabulary
development, discourse
skills, and phonological awareness
, all of which supports successful literacy learning. Communication partners are encouraged to provide augmented input with the child, such as signing or pointing to symbols and codes as they communicate, including using the individual's communication system themselves. They also benefit from focussed and explicit reading instruction.
Researchers hypothesize that using an AAC device relieves the pressure of having to speak, allowing the individual to focus on communication, and that the reduction in psychological stress makes speech production easier. Others speculate that in the case of speech generating devices, the model of spoken output leads to an increase in speech production.
Language and literacy have far reaching effects as they facilitate self-expression and social interaction in a variety of settings. Furthermore, literacy fosters independence by providing access to educational and vocational opportunities. Children whose disabilities require AAC often experience developmental delays in language skills such as vocabulary knowledge, length of sentences, syntax
, and impaired pragmatic
skills. These delays may be due in part to the fact that expressive language is limited by more than the children's own language knowledge. Unlike speaking children, children who use AAC do not always have access to their AAC system, and don't select the content available on the device. These external characteristics may impact language learning opportunities. Most children in this category do not achieve literacy skills beyond that of a typically developing 7–8 year old. Cognitive, language and learning delays contribute to difficulty with literacy development, but environmental factor
s also play a role. The most literate AAC users often report having access to abundant reading and writing material at home as well as in school during childhood. Studies have shown that many children who use AAC have literacy experiences that are reduced quality, quantity, and opportunity at home and at school as compared to children without disabilities. Research suggests that with explicit reading instruction, AAC users can develop good literacy skills.
report less than 10% of severely disabled individuals were employed. Despite the various barriers to employment, some AAC users achieve success in educational endeavours and employment, though often in lower paying jobs. Factors that have been found to be related to employment are a strong work ethic
and access to AAC technology, the support of family and friends, education, and work skills. Individuals with ALS who use AAC may continue working; factors supporting continued employment include access to AAC, support from employers, governmental programs and others. Employers of AAC users report that skills in time management
, problem solving
, communication, technology and a good education are important to employers.
is an umbrella term encompassing several developmental neuromotor disorders
with a common upper motor neuron lesion origin. Those with dysarthria
, a speech disorder resulting from neurological damage to the motor-speech system, may require AAC support for communication. Gross and fine motor challenges may be of particular concern in accessing the AAC device.
(the transfer of learned skills into daily activities). They may lack communication opportunities in their daily lives, and responsive communicators who understand their communication methods. AAC intervention for this population emphasizes partner training as well as opportunities for integrated, natural communication. Studies have shown that appropriate use of AAC techniques with children and adults with intellectual impairments can enhance communication skills, increase participation in activities, choice-making, and even influence the perceptions and stereotypes of communication partners.
While most individuals with intellectual disabilities do not have concomitant behavioural issues
, problems in this area are typically more prevalent in this population than others. AAC approaches may be used as part of teaching functional communication skills to non-speaking individuals as an alternative to "acting out" for the purpose of exerting independence, taking control, or informing preferences.
is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behaviour. Typically there is particular difficulty acquiring expressive communication skills. Children with autism have been found to have strong visual processing
skills, making them good candidates for an AAC approach.
AAC intervention in this population is directed towards the linguistic and social abilities of the child, including providing the child with a concrete means of communication, as well as facilitating the development of interactional skills.
AAC systems for this population generally begin with communication boards and/or object or picture exchanges such as the Picture Exchange Communication System (PECS). A 2009 descriptive review provided preliminary evidence that PECS is easily learned by most individuals with autism, provides communication to those with little or no functional speech, and has some limited positive impact on social interaction
and challenging behaviour
s. A study that compared the use of a speech generating device to a picture exchange system found that both were reasonable options for children with autism, as the ease and speed of acquisition of each system was similar.
A wide variety of AAC systems have been used with children with developmental dyspraxia. Manual signs or gestures are frequent introduced to these children, and can include the use of fingerspelling
alongside speech. Manual signs have been shown to decrease errors in articulation. Aided AAC systems typically include communication boards and speech generating devices. A multimodal approach is often used, with several AAC approaches introduced so that the child can take advantage of the most effective method for a particular situation.
can result in severe motor speech disorders; dysarthria
is the most common such disorder, accounting for roughly a third of all cases. Depending on the stage of recovery, AAC intervention may involve identifying consistent communication signals, the facilitation of reliable yes/no responses to questions, and the ability to express basic needs and answer questions. Individuals who do not recover natural speech to a degree sufficient to meet their communication needs typically suffer from severe impairments related to cognition. Difficulties with memory and learning new skills may influence AAC choices; well-established competencies such as spelling may be more effective than AAC systems that require navigation through multiple pages to access information.
is the result of damage to the brain's language centres affecting production, comprehension, or both, and can cause severe, chronic language impairment. Individuals with aphasia often communicate using a combination of speech, gestures, and aided communication; the proportion of each may change as the person recovers, and depends on the context and the individual's skills.
Depending on their language and cognitive skills, those with aphasia may use AAC interventions such as communication and memory books, drawing, photography, written words, speech generating devices and keyboards. Visual scene displays have been used on communication devices with adults who have chronic, severe aphasia; these feature photos of people, places or events that are meaningful to the individual and facilitative of communicative interaction. Approaches such as "Supported Conversation for Adults with Aphasia" train the communication partners to use resources such as writing key words, providing written choices, drawing, and using items such as photographs and maps to help the individual with aphasia produce and comprehend conversation.
s that occur in the brainstem may cause profound deficits, including locked-in syndrome
, in which cognitive, emotional and linguistic abilities remain intact but all or almost all voluntary motor abilities are lost. Most people affected by this type of stroke rely on AAC strategies to communicate, since few recover intelligible speech or functional voice. The AAC strategies used vary with the individual's preferences and motor capabilities which may change over time. As eye movements are most likely to be preserved, eye blinks are frequently used for communication. Low-tech alphabet boards are often introduced immediately to provide the individual with basic communication. Partner-assisted scanning may be used, in which the AAC user signals when the desired letter is named by a communication partner. When vertical and horizontal eye movements are functional, a transparent alphabet board may be used in which the AAC user looks at the desired letter and this is acknowledged by the communication partner. Individuals with locked-in syndrome have difficulty using high-tech devices due to issues with motor control
, vision, memory, alertness
and linguistic ability. In particular, a voluntary, reliable and easily controlled muscle movement is necessary to access such a device, such as head, jaw, hand or finger movements. In some individuals, intensive practice, even long after the initial stroke, has been shown to increase the accuracy and consistency of head movements, which can be used to access a communication device.
(ALS) or Motor Neurone Disease
(MND) is a progressive condition which leads to weakness and eventual paralysis
. Approximately 75% of people with ALS are unable to speak by the time of their death. In a procedure known as voice banking, people with ALS may digitally record words and phrases while still able to do so, for later inclusion in a communication device. AAC systems used typically change over time depending on severity of speech impairment, physical status, and the individual's communication needs. Use of augmentative communication strategies generally begins when speaking rate drops to 100 words per minute. In the early stages, AAC may consist of using an alphabet board to cue the listener to the first letter of the word being spoken, and may be used with those less familiar with the individual. In the later stages, AAC often becomes the main communicative method, although familiar conversation partners may still understand some spoken words. Since cognition and vision are typically unaffected in ALS, writing-based systems are preferred to graphic symbols, as they allow the unlimited expression of all words in a language.
The method of access to a communication device depends on the type and severity of the disease. In the spinal form of ALS, the limbs are affected from the onset of the disease; in these cases a head mouse or eye tracking access may be used initially. In the bulbar form, speech is affected before the limbs; here handwriting and typing on keyboard-style devices are frequently the first forms of AAC. AAC users may change access methods as the disease progresses. Low-tech systems, such as eye gazing or partner assisted scanning, are used in situations when electronic devices are unavailable (for example, during bathing) and in the final stages of the disease.
is a progressive neurological condition in which dysarthria
may develop later in the progression of the disease. Some individuals eventually lose all functional speech. AAC approaches are generally used to supplement and support natural speech. A portable amplifier, for example, may be used to increase the volume of speech and thus its intelligibility. The individual may be taught to point to the first letter of each word they say on an alphabet board, leading to a reduced speech rate and visual cues for the listener to compensate for impaired articulation. Entire words can be spelled out if necessary. In users that have reduced range and speed of movement, a smaller than usual selection display may be preferred. High-tech AAC keyboard speech-generating devices are also used; keyguards may be required to prevent accidental keystrokes caused by the tremor
typical of the disease. Factors affecting AAC use in Parkinson's disease include motor deficits and cognitive changes; the latter may result in unawareness of their problems with spoken communication.
(MS), however, significant difficulties with speech and intelligibility are uncommon. Individuals with MS vary widely in their motor control capacity and the presence of intention tremor
, and methods of access to AAC technology are adapted accordingly. Visual impairments are common in MS and may necessitate approaches using auditory scanning systems, large-print text, or synthetic speech feedback that plays back words and letters as they are typed.
is an acquired, chronic, cognitive impairment
characterized by deficits in memory and other cognitive domains. Communication impairments are partly attributed to memory deficits, and AAC intervention may be used to compensate for deficits and to capitalize on the person's strengths, such as the ability to recognize material they cannot recall. Low-tech devices are generally preferred, such as memory books that include autobiographical information, daily schedules, photographs, and reminders or labels. Several studies have shown positive outcomes in the amount of on-topic conversation and the length of interaction with these approaches. The gains were maintained four months after the training in the use of the memory aids had ceased. High-tech devices with voice output have been found to be less effective; in one study devices resulted in limited topic elaboration/initiation, reduced output and heightened distraction. AAC is also used to enhance the comprehension of those with dementia. The use of augmented listening strategies, such as identifying topics of conversation with pictures, improves the conversational skills of individuals with dementia.
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The history of AAC can be traced to the days of classical Rome and Greece
, with the first recorded use of augmentative strategies with the deaf. The use of manual alphabets and signs was recorded in Europe from the 16th century, as was the gestural system of Hand Talk used by Native Americans
to facilitate communication between different linguistic groups. The first known widely available communication aid was a letter and word-based communication board developed for, and with, F. Hall Roe, who had cerebral palsy. This communication board was distributed in the 1920s by a men's group in Minneapolis.
The modern era of AAC began in the 1950s in Europe and North America, spurred by several societal changes; these included an increased awareness of individuals with communication and other disabilities, and a growing commitment, often backed by government legislation and funding, to develop their education, independence and rights. In the early years, AAC was primarily used with laryngectomy
and glossectomy
cases, and later with individuals with cerebral palsy and aphasia. It was typically only employed after traditional speech therapy had failed, as many felt hesitant to provide non-speech intervention to those who might be able to learn to speak. Individuals with intellectual impairment were not provided with AAC support because it was believed that they did not possess the prerequisite skills for AAC. The main systems used were manual signs, communication boards and Morse code, though in the early 1960s, an electric communication device in the form of a sip-and-puff typewriter controller named the Patient Operated Selector Mechanism (POSM or POSSUM) was developed in the United Kingdom.
From the 1960s onward, sign language increased in acceptance and use in the Deaf community
, and AAC also came to be viewed as acceptable for those with other diagnoses. Manual sign languages, such as Makaton
, were advocated for those with both hearing and cognitive impairments, and later for those with intellectual impairment or autism with normal hearing. Research into whether primate
s could learn to sign or use graphic symbols spurred further interest the use of AAC with those with cognitive impairments. The use of Amer-Ind hand signals
opened the field to AAC techniques specifically for adult users.
Blissymbols
were first used in Canada in 1971 to provide communication to those not able to use traditional orthography; their use quickly spread to other countries. With improved technology, keyboard communication devices developed in Denmark, the Netherlands and the US increased in portability; the typed messages were displayed on a screen or strip of paper. By the end of the 1970s, communication devices were being commercially produced, and a few, such as the HandiVoice, had voice output. Countries such as Sweden, Canada and the United Kingdom initiated government-funded services for those with severe communication impairments, including developing centres of clinical and research expertise.
The late 1970s and 1980s saw a massive increase of AAC-related research, publications, and training as well the first national and international conferences. The International Society for Alternative and Augmentative Communication
(ISAAC) was founded in 1983; its members included clinicians, teachers, rehabilitation engineers, researchers, and AAC users themselves. The organization has since played an important role in developing the field through its peer-reviewed journal, conferences, national chapters and its focus on AAC in developing countries. AAC became an area of professional specialization; a 1981 American Speech-Language-Hearing Association
position paper, for example, recognized AAC as a field of practice for speech-language pathologists. At the same time, AAC users and family members played an increasing prominent role in the development of knowledge of AAC through their writing and presentations, by serving on committees and founding advocacy organizations.
From the 1980s, improvements in technology led to a greatly increased number, variety, and performance of commercially available communication devices, and a reduction in their size and price. Alternative methods of access such eye pointing or scanning became available on communication devices. Speech output possibilities included digitized and synthesized speech, with text-to-speech options available in German, French, Italian, Spanish, Swedish and Ewe
. AAC services became more holistic, seeking to develop a balance of aided and unaided strategies with the goal of improving functioning in the person's daily life, and greater involvement of the family. Increasingly, individuals with acquired conditions such as amyotrophic lateral sclerosis, Parkinson's disease, head injury, and locked-in syndrome, received AAC services. In addition, with the challenge to the notion of AAC prerequisites, those with severe to profound intellectual impairments began to be served. Courses on AAC were developed for professional training programs, and literature such as textbooks and guides were written to support students, clinicians and parents.
The 1990s brought a focus on greater independence for people with disabilities, and more inclusion in mainstream society . In schools, students with special needs
were placed in regular classrooms rather than segregated settings, which led to an increased use of AAC as a means of improving student participation in class. Interventions became more collaborative and naturalistic, taking place in the classroom with the teacher, rather than in a therapy room. Facilitated communication
– a method by which a facilitator physically and emotionally supports a person with severe communication needs as they type on a keyboard or letter board – received wide attention in the media and in the field. The question of the authorship made the approach controversial; most of the subsequent research indicated that the facilitators were unknowingly influencing the messages typed. As a result, professional organizations and AAC researchers and clinicians have not typically accepted facilitated communication.
Rapid progress in hardware and software
development continued, including projects funded by the European Community. The first commercially available dynamic screen speech generating devices were developed in the 1990s. At the same time synthesized speech was becoming available in more languages. Software programs were developed that allowed the computer-based production of communication boards. High-tech devices have continued to reduce in size and weight, while increasing accessibility and capacities. Modern communication devices can also enable users to access the internet and some can be used as environmental control devices
for independent access of TV, radio, telephone etc.
Umbrella term
An umbrella term is a word that provides a superset or grouping of concepts that all fall under a single common category. Umbrella term is also called a hypernym. For example, cryptology is an umbrella term that encompasses cryptography and cryptanalysis, among other fields...
that encompasses the communication methods used to supplement or replace speech or writing for those with impairments in the production or comprehension of spoken or written language. AAC is used by those with a wide range of speech and language impairment
Speech and language impairment
Speech and language impairment are basic categories that might be drawn in issues of communication involve hearing, speech, language, and fluency....
s, including congenital impairments such as cerebral palsy
Cerebral palsy
Cerebral palsy is an umbrella term encompassing a group of non-progressive, non-contagious motor conditions that cause physical disability in human development, chiefly in the various areas of body movement....
, intellectual impairment and autism
Autism
Autism is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behavior. These signs all begin before a child is three years old. Autism affects information processing in the brain by altering how nerve cells and their...
, and acquired conditions such as amyotrophic lateral sclerosis
Amyotrophic lateral sclerosis
Amyotrophic lateral sclerosis , also referred to as Lou Gehrig's disease, is a form of motor neuron disease caused by the degeneration of upper and lower neurons, located in the ventral horn of the spinal cord and the cortical neurons that provide their efferent input...
and Parkinson's disease
Parkinson's disease
Parkinson's disease is a degenerative disorder of the central nervous system...
. AAC can be a permanent addition to a person's communication or a temporary aid.
Modern use of AAC began in the 1950s with systems for those who had lost the ability to speak following surgical procedures. During the 1960s and 1970s, spurred by an increasing commitment in the West towards the inclusion
Inclusion (disability rights)
Inclusion is a term used by people with disabilities and other disability rights advocates for the idea that all people should freely, openly and without pity accommodate any person with a disability without restrictions or limitations of any kind...
of disabled individuals in mainstream society and developing the skills required for independence, the use of manual sign language
Sign language
A sign language is a language which, instead of acoustically conveyed sound patterns, uses visually transmitted sign patterns to convey meaning—simultaneously combining hand shapes, orientation and movement of the hands, arms or body, and facial expressions to fluidly express a speaker's...
and then graphic symbol communication grew greatly. It was not until the 1980s that AAC began to emerge as a field in its own right. Rapid progress in technology, including microcomputers and speech synthesis
Speech synthesis
Speech synthesis is the artificial production of human speech. A computer system used for this purpose is called a speech synthesizer, and can be implemented in software or hardware...
, have paved the way for communication devices with speech output and multiple options for access to communication for those with physical disabilities
Physical disability
A physical disability is any impairment which limits the physical function of one or more limbs or fine or gross motor ability. Other physical disabilities include impairments which limit other facets of daily living, such as respiratory disorders and epilepsy....
.
AAC systems are extremely diverse: unaided communication uses no equipment and includes signing and body language
Body language
Body language is a form of non-verbal communication, which consists of body posture, gestures, facial expressions, and eye movements. Humans send and interpret such signals almost entirely subconsciously....
, while aided approaches use external tools and range from pictures and communication boards to speech generating devices. The symbols used in AAC include gestures, photographs, pictures, line drawings, letters and words, which can be used alone or in combination. Body parts, pointers, adapted mice, or eye tracking
Eye tracking
Eye tracking is the process of measuring either the point of gaze or the motion of an eye relative to the head. An eye tracker is a device for measuring eye positions and eye movement. Eye trackers are used in research on the visual system, in psychology, in cognitive linguistics and in product...
can be used to select target symbols directly, and switch access scanning
Switch access scanning
Switch access scanning is an indirect selection technique , used by an assistive technology user, including those who use augmentative and alternative communication to choose items from the selection set...
is often used for indirect selection. Message generation is generally much slower than spoken communication, and as a result rate enhancement techniques may be used to reduce the number of selections required. These techniques include "prediction", in which the user is offered guesses of the word/phrase being composed, and "encoding", in which longer messages are retrieved using a prestored code.
The evaluation of a user's abilities and requirements for AAC will include the individual's motor, visual, cognitive, language and communication strengths and weaknesses. The evaluation requires the input of family members, particularly for early intervention. Respecting ethnicity and family beliefs are key to a family-centered
Family centered care
Family-centered care or Family-centered service has been discussed and promoted most prominently in the context of child health, and especially concerning chronic conditions of childhood. This approach provides an expanded view of how to work with children and families...
and ethnically competent approach. Studies show that AAC use does not impede the development of speech, and may result in a modest increase in speech production. Users who have grown up with AAC report satisfying relationships and life activities; however, they may have poor literacy and are unlikely to be in employment.
Scope
Augmentative and alternative communication is used by individuals to compensate for severe speech-language impairments in the expression or comprehension of spoken or written language. People making use of AAC include individuals with a variety of congenital conditions such as cerebral palsy, autism, intellectual disability, and acquired conditions such as amyotrophic lateral sclerosis, traumatic brain injury and aphasia. PrevalencePrevalence
In epidemiology, the prevalence of a health-related state in a statistical population is defined as the total number of cases of the risk factor in the population at a given time, or the total number of cases in the population, divided by the number of individuals in the population...
data vary depending on the country and age/disabilities surveyed, but typically between 0.1 to 1.5% of the population are considered to have such severe speech-language impairments that they have difficulty making themselves understood, and thus could benefit from AAC. An estimated 0.05% of children and young people require high technology AAC. Well-known AAC users include physicist Stephen Hawking
Stephen Hawking
Stephen William Hawking, CH, CBE, FRS, FRSA is an English theoretical physicist and cosmologist, whose scientific books and public appearances have made him an academic celebrity...
, broadcaster Roger Ebert
Roger Ebert
Roger Joseph Ebert is an American film critic and screenwriter. He is the first film critic to win a Pulitzer Prize for Criticism.Ebert is known for his film review column and for the television programs Sneak Previews, At the Movies with Gene Siskel and Roger Ebert, and Siskel and Ebert and The...
and poet Christopher Nolan
Christopher Nolan (author)
Christopher Nolan was an Irish poet and author, son of Joseph and Bernadette Nolan. He grew up in Mullingar, Ireland, but later moved to Dublin to attend college. He was educated at the Central Remedial Clinic School, Mount Temple Comprehensive School and at Trinity College, Dublin. His first...
. Award-winning films such as My Left Foot
My Left Foot (film)
My Left Foot: The Story of Christy Brown is a 1989 drama film directed by Jim Sheridan and starring Daniel Day-Lewis. It tells the true story of Christy Brown, an Irishman born with cerebral palsy, who could control only his left foot. Christy Brown grew up in a poor, working class family, and...
and The Diving Bell and the Butterfly
The Diving Bell and the Butterfly (film)
The Diving Bell and the Butterfly is a 2007 biographical drama film based on Jean-Dominique Bauby's memoir of the same name. The film depicts Bauby's life after suffering a massive stroke, on December 8, 1995, at the age of 42, which left him with a condition known as locked-in syndrome. The...
, based on books by AAC users Christy Brown
Christy Brown
Christy Brown was an Irish author, painter and poet who had cerebral palsy. He is most famous for his autobiography My Left Foot, which was later made into an Academy Award-winning film of the same name....
and Jean-Dominique Bauby
Jean-Dominique Bauby
Jean-Dominique Bauby was a well-known French journalist, author and editor of the French fashion magazine ELLE.On 8 December 1995 at the age of 43, Bauby suffered a massive stroke. When he woke up twenty days later, he found he was entirely speechless; he could only blink his left eyelid...
respectively, have brought the lives of those who use AAC to a wider audience.
The field was originally called "Augmentative Communication"; the term served to indicate that such communication systems were to supplement natural speech rather than to replace it. The addition of "alternative" followed later, when it became clear that for some individuals non-speech systems were their only means of communication. AAC users typically utilize a variety of aided and unaided communication strategies depending on the communication partners and the context.
Unaided AAC
Unaided AAC systems are those that do not require an external tool, and include facial expression, vocalizations, gestures, and signed languages and systems. Informal vocalizations and gestures such as body language and facial expressions are part of natural communication, and such signals may be used by those with profound disabilities. More formalized gestural codes exist that lack a base in a naturally occurring language. For example, the Amer-Ind code is based on Plains Indian Sign LanguagePlains Indian Sign Language
The Plains Indian sign languages are various manually coded languages used, or formerly used, by various Native Americans of the Great Plains of the United States of America and Canada...
, and has been used with children with severe-profound disabilities, and adults with a variety of diagnoses including dementia
Dementia
Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...
, aphasia
Aphasia
Aphasia is an impairment of language ability. This class of language disorder ranges from having difficulty remembering words to being completely unable to speak, read, or write....
and dysarthria
Dysarthria
Dysarthria is a motor speech disorder resulting from neurological injury of the motor component of the motor-speech system and is characterized by poor articulation of phonemes...
. The benefits of gestures and pantomime are that they are always available to the user, usually understood by an educated listener, and are efficient means of communicating.
In contrast, sign languages have a linguistic base and permit the expression of an unlimited number of messages. Approaches to signing can be divided into two major categories, those that encode an existing language, and those that are languages in their own right. Signing Exact English
Signing Exact English
Signing Exact English is a system of manual communication that strives to be an exact representation of English vocabulary and grammar...
may be considered the most widely used example of the former and American Sign Language
American Sign Language
American Sign Language, or ASL, for a time also called Ameslan, is the dominant sign language of Deaf Americans, including deaf communities in the United States, in the English-speaking parts of Canada, and in some regions of Mexico...
as a common example of the latter. Signing is used alone or in conjunction with speech to support communication with individuals with a variety of disorders. The specific hand shapes and movements of sign and gesture require an individual to have adequate fine motor and motor planning skills. Sign languages require more fine-motor coordination and are less transparent
Transparency (linguistic)
Linguistic transparency is a phrase which is used in multiple, overlapping subjects in the fields of linguistics and the philosophy of language...
in meaning than gestural codes such as Amer-Ind; the latter limits the number of people able to understand the person's communication without training.
Aided AAC
An AAC aid is any "device, either electronic or non-electronic, that is used to transmit or receive messages"; such aids range from communication books to speech generating devices. Since the skills, areas of difficulty and communication needs of AAC users vary greatly, an equally diverse range of communication aids and devices is required.Low-tech
Low-tech communication aids are defined as those that do not need batteries, electricity or electronics. These are often very simple communication boards or books, from which the user selects letters, words, phrases, pictures, and/or symbols to communicate a message. Depending on physical abilities and limitations, users may indicate the appropriate message with a body part, light pointer, eye-gaze direction, or a head/mouth stick. Alternatively, they may indicate yes or no while a listener scans through possible options.High-tech
High-tech AAC aids permit the storage and retrieval of electronic messages, with most allowing the user to communicate using speech output. Such devices are known as speech generating devices (SGD) or voice output communication aids (VOCA). A device's speech output may be digitized and/or synthesized: digitized systems play recorded words or phrases and are generally more intelligible while synthesized speechSpeech synthesis
Speech synthesis is the artificial production of human speech. A computer system used for this purpose is called a speech synthesizer, and can be implemented in software or hardware...
uses text-to-speech software that can be harder to understand but that permits the user to spell words and speak novel messages.
High-tech systems may be dedicated devices developed solely for AAC, or non-dedicated devices such as computers that run additional software to allow them to function as AAC devices. They may be static or dynamic in form. Static communication devices have symbols in fixed positions on paper overlays, which are changed manually. To increase the vocabulary available, some static devices have multiple levels, with different words appearing on different levels. On dynamic AAC devices, the user can change the symbols available using page links to navigate to appropriate pages of vocabulary and messages.
High-tech devices vary in the amount of information that they can store, as well as their size, weight and thus their portability. Access methods depend on the abilities of the user, and may include the use of direct selection of symbols on the screen or keyboard with a body part, pointer, adapted mice
Mouse (computing)
In computing, a mouse is a pointing device that functions by detecting two-dimensional motion relative to its supporting surface. Physically, a mouse consists of an object held under one of the user's hands, with one or more buttons...
or joysticks, or indirect selection using switches and scanning. Devices with voice output offer its user the advantage of more communicative power, including the ability to initiate conversation with communication partners who are at a distance. However, they typically require programming, and tend to be unreliable. Because of the latter, low tech systems often recommended as a backup in case of device failure.
Symbols
Symbols used on high and low-tech AAC systems include graphic, auditory, gestural and textural symbols to represent objects, actions and concepts.For users with literacy skills, both low and high-tech devices may use alphabet-based symbols including individual letters, whole words, or parts thereof. With low-tech devices, the communication partner must interpret the symbols chosen whereas a high-tech device can speak the created message aloud. Several large graphic symbol sets have been developed; these include Blissymbols
Blissymbols
Blissymbols or Blissymbolics was conceived as an ideographic writing system called Semantography consisting of several hundred basic symbols, each representing a concept, which can be composed together to generate new symbols that represent new concepts...
, which possess linguistic characteristics such as grammatical indicators, and the more iconic Picture Communication Symbols
Picture communication symbols
Picture Communication Symbols are a set of colour and black & white drawings originally developed by Mayer-Johnson, LLC for use in augmentative and alternative communication systems...
(PCS) which do not.
Tactile symbols
Tangible symbol systems
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...
are textured objects, real objects or parts of real objects that are used as a communication symbols particularly for individuals with visual impairment
Visual impairment
Visual impairment is vision loss to such a degree as to qualify as an additional support need through a significant limitation of visual capability resulting from either disease, trauma, or congenital or degenerative conditions that cannot be corrected by conventional means, such as refractive...
s and/or significant intellectual impairments.
Auditory symbols such as choices of spoken words or Morse code
Morse code
Morse code is a method of transmitting textual information as a series of on-off tones, lights, or clicks that can be directly understood by a skilled listener or observer without special equipment...
can also be integrated with assistive technology for the visually impaired.
The choice of symbols and aspects of their presentation, such as size and background, depend on an individual's preferences as well as their linguistic, visual, and cognitive skills.
Access and selection methods
Technological advances have dramatically increased the types of selection methods available for individuals with communication impairments.In "Direct Selection", the selection is made by pointing to the desired symbol using a finger or an alternative pointer, such as eye gaze, a head stick, head- or eye-controlled mouse. To accommodate motor control difficulties some users use alternative activation strategies; for example in "timed activation", the user maintains selection of the symbol for a predetermined period of time until it is recognized by the system. With the "release activation", the selection of the item is only made when the person releases contact from the display.
Direct activation of an AAC system is generally the first choice of access method as it is faster and cognitively easier. Those unable to do so may use indirect selection or "scanning". In this method, items displayed for selection are scanned; the scanning may be visual using indicators such as lights, highlighting, and/or contrasting borders, or auditory using spoken prompts from a communication partner or device. When the desired message is reached, the AAC user indicates the choice using an alternative selection technique such as a switch
Switch Access
Many people with severe physical or cognitive impairment use one or more switches to access computers. A switch is an assistive technology device that replaces the need to use a computer keyboard or a mouse.-Types of switch:...
, vocalization or gesture. Several different patterns for switch access scanning
Switch access scanning
Switch access scanning is an indirect selection technique , used by an assistive technology user, including those who use augmentative and alternative communication to choose items from the selection set...
are available: in "circular scanning", the items are displayed in a circle and then scanned one at a time. It is often introduced first to children or beginning AAC users because it is the easiest to understand. In "linear scanning", items are organized in rows and are scanned one at a time until a choice is made. Although more demanding than circular scanning, it is still easy to learn. Finally, in "group-item scanning", items are grouped and the groups scanned consecutively. Once a particular group is selected, items within the group are scanned. One of the most common group-item strategies is row-column scanning in which each row forms a group. The rows of items are scanned and when a row is selected, the items in the row are scanned one at a time until a message is selected.
There are three main selection control techniques in scanning. In "automatic scanning", the scan proceeds at a pre-determined speed and pattern until the user selects an item. In "inverse scanning", the switch is held down to advance the scan, and released to choose the desired iem. In "step scanning", the AAC user activates one switch to move the indicator through the items, and another switch to select the item.
Vocabulary organization
Vocabulary organization refers to the way pictures, words, phrases, and sentences are displayed on the communication system. In general, the goal is to facilitate efficient and effective communication, especially when the individual's AAC system contains a large number of symbols.Communication books and devices are often presented in a grid format; the vocabulary items displayed within them may be organized by spoken word order, frequency of usage or category. In the Fitzgerald Key organization, symbols from different semantic and syntactic classes are organized in groups from left to right to facilitate sentence construction. Since research has shown that children and adults use a small number of words frequently, in a core-fringe vocabulary organization, the words and messages that are communicated most frequently appear on a "main page". The fringe vocabulary—words and messages used more rarely and that are specific to an individual—appear on other pages. Symbols may also be organized by category, grouping people, places, feelings, foods, drinks, and action words together. Another form of grid organization groups vocabulary according to specific activities. Each display contains symbols for the people, places, objects, feelings, actions, and other relevant vocabulary items for a specific activity or routine.
Visual scene displays are a different method of organizing and presenting symbols. These are depictions of events, people, objects, and related actions in a picture, photograph, or virtual environment representing a situation, place, or specific experience. They are similar to activity displays in that they contain vocabulary that is associated with specific activities or routines. For example, a photo of a child's room may be included in the child's AAC system. Objects and events within the photograph are then used as symbols for communication. Research suggests that visual scene displays are easier than grid displays for young children or those with cognitive impairments to learn and use.
A bottleneck in High-tech AAC is that users must program new utterances manually (e.g. names of new friends). Research approaches attempting to overcome this bottleneck range from generating content based on a log of conversation with a user's friends and family, to data mined from the internet for language materials, By accessing more of a user's data, more high-quality messages can be generated at a risk of exposing sensitive user data For example, by making use of global positioning systems, a device's content can be changed based on geographical location. Moreover, by making use of Lifelog
Lifelog
Lifeloggers typically wear computers in order to capture their entire lives, or large portions of their lives.- Overview :...
ging based approaches, a device's content can be changed based on events that occur to a user during their day.
Rate enhancement strategies
Augmentative and alternative communication is typically much slower than speech, with users generally producing 8–10 words per minute. Rate enhancement strategies can increase the user's rate of output to around 12–15 words per minute, and as a result enhance the efficiency of communication. There are two main options for increasing the rate of communication: encoding and prediction.Encoding is a technique permitting an AAC user to produce an entire word, sentence or phrase using only one or two activations of their AAC system. In numeric, alpha-numeric, and letter encoding (also known as abbreviation-expansion), words and sentences are coded as sequences of letters and numbers. For example, typing "HH" may retrieve "Hello, how are you?". In iconic encoding strategies, such as Semantic compaction
Semantic compaction
Semantic compaction also known as iconic encoding or Minspeak, is an Augmentative and alternative communication technique in which sequences of icons are combined in order a word or a phrase from an AAC device in order increase a person's rate of speech.-Conceptual basis:Linguist Bruce Baker was...
, icons (picture symbols) are combined in a sequence to produce words or phrases.
Prediction is a rate enhancement strategy in which the device attempts to predict the letter, word or phrase being written by the user. The user can then select the correct prediction without needing to write the full word. Word prediction
Word prediction
Word prediction is the provision of words that are frequently used in response to a user's keystrokes.-Purpose:The original purpose of word prediction software was to help people with physical disabilities increase their typing speed, as well as to help them decrease the number of keystrokes needed...
software may determine the words predicted based on their frequency in language, association with other words, past choices of the user, or grammatical suitability.
Assessment and system implementation
An evaluation of an individual's abilities, limitations and communication needs is necessary to select appropriate AAC techniques. The purpose of the assessment is to identify potential AAC approaches that can bridge discrepancies between a potential user's current communication and their present and future communication needs. AAC evaluations are often conducted by specialized teams which may include a speech-language pathologist, occupational therapistOccupational therapist
An occupational therapist is trained in the practice of occupational therapy. The role of an occupational therapist is to work with a client to help them achieve a fulfilled and satisfied state in life through the use of "purposeful activity or interventions designed to achieve functional...
, rehabilitation engineer, physiotherapist, social worker and a physician
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...
. Users, family members and teachers are also key members of the decision making team. Sensitivity to and respect of cultural diversity
Cultural diversity
Cultural diversity is having different cultures respect each other's differences. It could also mean the variety of human societies or cultures in a specific region, or in the world as a whole...
contributes to ongoing family involvement and to the selection of the most appropriate AAC system. For members of some cultural groups the presence of an AAC device increases the visibility of disability and is thus viewed as stigmatizing.
A user's motor abilities, communication skills and needs, cognition
Cognition
In science, cognition refers to mental processes. These processes include attention, remembering, producing and understanding language, solving problems, and making decisions. Cognition is studied in various disciplines such as psychology, philosophy, linguistics, and computer science...
and vision are assessed in order to determine the most appropriate match to a communication system. Depending on the individual's physical status, recommendations of an alternative access method, a change in seating/positioning, a mounting system and/or communication aid adaptations may be needed. For example, someone with spastic
Spasticity
Spasticity is a feature of altered skeletal muscle performance in muscle tone involving hypertonia, which is also referred to as an unusual "tightness" of muscles...
arm movements may require a key guard on top of the keyboard or touchscreen
Touchscreen
A touchscreen is an electronic visual display that can detect the presence and location of a touch within the display area. The term generally refers to touching the display of the device with a finger or hand. Touchscreens can also sense other passive objects, such as a stylus...
to reduce the selection of non-target items. The person's needs and abilities determine the symbols chosen and their organization, with the goal being that the communication system can be used as efficiently as possible in different contexts, with different communication partners, and for different social purposes. Researcher Janice Light identified four social purposes of communicative interaction in AAC: the expression of needs and wants to a listener, the transfer of information as in more general conversation, the development of social closeness through such things as jokes and cheering, and finally social etiquette practices such as "please" and "thank you". These four purposes vary in terms of the relative importance of the content, rate, duration and the focus of the interaction. It is important that the AAC systems selected also reflect the priorities of the individual and their family. In Western cultures, professionals may see a communication device as helping to promote an individual's self-determination
Self-determination (philosophy)
Self-determination is the idea of a positive freedom, a freedom for actions that we originate, actions that are "up to us." Such acts constitute the essence of free will. This is Mortimer Adler's term, translating ideas from Aristotle and Aquinas...
, i.e., the ability to make one's own decisions and choices. However, cultural and religious factors may affect the degree to which individual autonomy is a valued construct, and influence family attitudes towards AAC.
Training can help the user make use of their AAC system to communicate effectively with others, to control their environment through communication, and to make choices, decisions and mistakes. Skilled users of AAC show communicative competence
Communicative competence
Communicative competence is a term in linguistics which refers to a language user's grammatical knowledge of syntax, morphology, phonology and the like, as well as social knowledge about how and when to use utterances appropriately....
in four interrelated areas: linguistic, operational, social and strategic. Linguistic competence
Linguistic competence
Linguistic competence is the system of linguistic knowledge possessed by native speakers of a language, it is in contrast to the concept of Linguistic performance, the way the language system is used in communication...
refers to language skills in the person's native language as well as the linguistic code of the symbol system selected. Operational competence involves the skills in the use and maintenance of the tool of communication, while social competence
Social competence
Social competence is a complex, multidimensional concept consisting of social, emotional , cognitive , and behavioral skills, as well as motivational and expectancy sets needed for successful...
and strategic competence reflect knowledge and judgment in communicative interactions, including the compensations required for a slow speaking rate, communication breakdowns and those unfamiliar with AAC. An AAC user may require specific device programming and/or training to achieve competency in these areas.
Communication partners may also require training to notice and consistently interpret the communication signals of a severely disabled individual, particularly because there is a danger that learned helplessness
Learned helplessness
Learned helplessness, as a technical term in animal psychology and related human psychology, means a condition of a human person or an animal in which it has learned to behave helplessly, even when the opportunity is restored for it to help itself by avoiding an unpleasant or harmful circumstance...
can be the result of repeated failure to communicate successfully. Parties may need assistance to avoid the directive communication style that can lead a child user of AAC not to develop a full range of communication skills such as initiating or taking the lead in conversation, using complex syntax, asking questions, making commands or adding new information.
Young AAC users benefit from rich language and literacy experiences to foster vocabulary
Vocabulary
A person's vocabulary is the set of words within a language that are familiar to that person. A vocabulary usually develops with age, and serves as a useful and fundamental tool for communication and acquiring knowledge...
development, discourse
Discourse
Discourse generally refers to "written or spoken communication". The following are three more specific definitions:...
skills, and phonological awareness
Phonological awareness
Phonological awareness refers to an individual's awareness of the phonological structure, or sound structure, of spoken words. Phonological awareness is an important and reliable predictor of later reading ability and has, therefore, been the focus of much research.- Overview :Phonological...
, all of which supports successful literacy learning. Communication partners are encouraged to provide augmented input with the child, such as signing or pointing to symbols and codes as they communicate, including using the individual's communication system themselves. They also benefit from focussed and explicit reading instruction.
Speech
Several reviews have found that the use of AAC does not impede the development of speech in individuals with autism or developmental disabilities, and in fact may result in modest gains being observed. A 2006 research review of 23 AAC intervention studies found gains in speech production in 89% of the cases studied, with the remainder showing no change. A descriptive review looking specifically at Picture Exchange Communication System (PECS) intervention studies found that several studies reported an increase in speech, often during later phases, while one noted little or no effect.Researchers hypothesize that using an AAC device relieves the pressure of having to speak, allowing the individual to focus on communication, and that the reduction in psychological stress makes speech production easier. Others speculate that in the case of speech generating devices, the model of spoken output leads to an increase in speech production.
Language and literacy
Language and literacy have far reaching effects as they facilitate self-expression and social interaction in a variety of settings. Furthermore, literacy fosters independence by providing access to educational and vocational opportunities. Children whose disabilities require AAC often experience developmental delays in language skills such as vocabulary knowledge, length of sentences, syntax
Syntax
In linguistics, syntax is the study of the principles and rules for constructing phrases and sentences in natural languages....
, and impaired pragmatic
Pragmatics
Pragmatics is a subfield of linguistics which studies the ways in which context contributes to meaning. Pragmatics encompasses speech act theory, conversational implicature, talk in interaction and other approaches to language behavior in philosophy, sociology, and linguistics. It studies how the...
skills. These delays may be due in part to the fact that expressive language is limited by more than the children's own language knowledge. Unlike speaking children, children who use AAC do not always have access to their AAC system, and don't select the content available on the device. These external characteristics may impact language learning opportunities. Most children in this category do not achieve literacy skills beyond that of a typically developing 7–8 year old. Cognitive, language and learning delays contribute to difficulty with literacy development, but environmental factor
Environmental factor
Environmental factor or ecological factor or ecofactor is any factor, abiotic or biotic, that influences living organisms.- Environmental factors inducing diseases :...
s also play a role. The most literate AAC users often report having access to abundant reading and writing material at home as well as in school during childhood. Studies have shown that many children who use AAC have literacy experiences that are reduced quality, quantity, and opportunity at home and at school as compared to children without disabilities. Research suggests that with explicit reading instruction, AAC users can develop good literacy skills.
Employment
According to a 1997 U.S. Census BureauUnited States Census Bureau
The United States Census Bureau is the government agency that is responsible for the United States Census. It also gathers other national demographic and economic data...
report less than 10% of severely disabled individuals were employed. Despite the various barriers to employment, some AAC users achieve success in educational endeavours and employment, though often in lower paying jobs. Factors that have been found to be related to employment are a strong work ethic
Work ethic
Work ethic is a set of values based on hard work and diligence. It is also a belief in the moral benefit of work and its ability to enhance character. An example would be the Protestant work ethic...
and access to AAC technology, the support of family and friends, education, and work skills. Individuals with ALS who use AAC may continue working; factors supporting continued employment include access to AAC, support from employers, governmental programs and others. Employers of AAC users report that skills in time management
Time management
Time management is the act or process of exercising conscious control over the amount of time spent on specific activities, especially to increase efficiency or productivity. Time management may be aided by a range of skills, tools, and techniques used to manage time when accomplishing specific...
, problem solving
Problem solving
Problem solving is a mental process and is part of the larger problem process that includes problem finding and problem shaping. Consideredthe most complex of all intellectual functions, problem solving has been defined as higher-order cognitive process that requires the modulation and control of...
, communication, technology and a good education are important to employers.
Quality of life
Several studies of young adults who had used AAC since childhood report a generally good quality of life, though few lived independently, or were in paid employment. The young adults used multiple modes of communication including aided and unaided AAC approaches. More positive quality of life outcomes often correlated with better quality of communication and interaction, as well as personal characteristics, family and community support, and excellent AAC services. Poorer outcomes were related to lack of access to appropriate AAC supports and resources, problems with technology and negative attitudes.Cerebral palsy
Cerebral palsyCerebral palsy
Cerebral palsy is an umbrella term encompassing a group of non-progressive, non-contagious motor conditions that cause physical disability in human development, chiefly in the various areas of body movement....
is an umbrella term encompassing several developmental neuromotor disorders
Movement disorder
Movement disorders include:* Akathisia * Akinesia * Associated Movements * Athetosis...
with a common upper motor neuron lesion origin. Those with dysarthria
Dysarthria
Dysarthria is a motor speech disorder resulting from neurological injury of the motor component of the motor-speech system and is characterized by poor articulation of phonemes...
, a speech disorder resulting from neurological damage to the motor-speech system, may require AAC support for communication. Gross and fine motor challenges may be of particular concern in accessing the AAC device.
Intellectual impairment
Individuals with intellectual impairments face challenges in developing communication skills, including problems with generalizationApplied Behavior Analysis
Applied behavior analysis is a science that involves using modern behavioral learning theory to modify behaviors. Behavior analysts reject the use of hypothetical constructs and focus on the observable relationship of behavior to the environment...
(the transfer of learned skills into daily activities). They may lack communication opportunities in their daily lives, and responsive communicators who understand their communication methods. AAC intervention for this population emphasizes partner training as well as opportunities for integrated, natural communication. Studies have shown that appropriate use of AAC techniques with children and adults with intellectual impairments can enhance communication skills, increase participation in activities, choice-making, and even influence the perceptions and stereotypes of communication partners.
While most individuals with intellectual disabilities do not have concomitant behavioural issues
Challenging behaviour
Challenging behaviour is defined as "culturally abnormal behaviour of such intensity, frequency or duration that the physical safety of the person or others is placed in serious jeopardy, or behaviour which is likely to seriously limit or deny access to the use of ordinary community...
, problems in this area are typically more prevalent in this population than others. AAC approaches may be used as part of teaching functional communication skills to non-speaking individuals as an alternative to "acting out" for the purpose of exerting independence, taking control, or informing preferences.
Autism
AutismAutism
Autism is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behavior. These signs all begin before a child is three years old. Autism affects information processing in the brain by altering how nerve cells and their...
is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behaviour. Typically there is particular difficulty acquiring expressive communication skills. Children with autism have been found to have strong visual processing
Visual processing
Visual processing is the sequence of steps that information takes as it flows from visual sensors to cognitive processing. The sensors may be zoological eyes or they may be cameras or sensor arrays that sense various portions of the electromagnetic spectrum....
skills, making them good candidates for an AAC approach.
AAC intervention in this population is directed towards the linguistic and social abilities of the child, including providing the child with a concrete means of communication, as well as facilitating the development of interactional skills.
AAC systems for this population generally begin with communication boards and/or object or picture exchanges such as the Picture Exchange Communication System (PECS). A 2009 descriptive review provided preliminary evidence that PECS is easily learned by most individuals with autism, provides communication to those with little or no functional speech, and has some limited positive impact on social interaction
Social relation
In social science, a social relation or social interaction refers to a relationship between two , three or more individuals . Social relations, derived from individual agency, form the basis of the social structure. To this extent social relations are always the basic object of analysis for social...
and challenging behaviour
Challenging behaviour
Challenging behaviour is defined as "culturally abnormal behaviour of such intensity, frequency or duration that the physical safety of the person or others is placed in serious jeopardy, or behaviour which is likely to seriously limit or deny access to the use of ordinary community...
s. A study that compared the use of a speech generating device to a picture exchange system found that both were reasonable options for children with autism, as the ease and speed of acquisition of each system was similar.
Developmental dyspraxia
Developmental dyspraxia (or apraxia of speech) is a childhood motor speech disorder involving impairments in the motor control of speech production. The speech of a child with developmental dyspraxia may be unintelligible to the point that daily communication needs cannot be met. A child with developmental dyspraxia often experiences great amounts of frustration, so AAC can be a strategy to support communication alongside more traditional speech therapy to improve speech production.A wide variety of AAC systems have been used with children with developmental dyspraxia. Manual signs or gestures are frequent introduced to these children, and can include the use of fingerspelling
Fingerspelling
Fingerspelling is the representation of the letters of a writing system, and sometimes numeral systems, using only the hands. These manual alphabets , have often been used in deaf education, and have subsequently been adopted as a distinct part of a number of sign languages around the world...
alongside speech. Manual signs have been shown to decrease errors in articulation. Aided AAC systems typically include communication boards and speech generating devices. A multimodal approach is often used, with several AAC approaches introduced so that the child can take advantage of the most effective method for a particular situation.
Traumatic brain injury
Traumatic brain injuryTraumatic brain injury
Traumatic brain injury , also known as intracranial injury, occurs when an external force traumatically injures the brain. TBI can be classified based on severity, mechanism , or other features...
can result in severe motor speech disorders; dysarthria
Dysarthria
Dysarthria is a motor speech disorder resulting from neurological injury of the motor component of the motor-speech system and is characterized by poor articulation of phonemes...
is the most common such disorder, accounting for roughly a third of all cases. Depending on the stage of recovery, AAC intervention may involve identifying consistent communication signals, the facilitation of reliable yes/no responses to questions, and the ability to express basic needs and answer questions. Individuals who do not recover natural speech to a degree sufficient to meet their communication needs typically suffer from severe impairments related to cognition. Difficulties with memory and learning new skills may influence AAC choices; well-established competencies such as spelling may be more effective than AAC systems that require navigation through multiple pages to access information.
Aphasia
AphasiaAphasia
Aphasia is an impairment of language ability. This class of language disorder ranges from having difficulty remembering words to being completely unable to speak, read, or write....
is the result of damage to the brain's language centres affecting production, comprehension, or both, and can cause severe, chronic language impairment. Individuals with aphasia often communicate using a combination of speech, gestures, and aided communication; the proportion of each may change as the person recovers, and depends on the context and the individual's skills.
Depending on their language and cognitive skills, those with aphasia may use AAC interventions such as communication and memory books, drawing, photography, written words, speech generating devices and keyboards. Visual scene displays have been used on communication devices with adults who have chronic, severe aphasia; these feature photos of people, places or events that are meaningful to the individual and facilitative of communicative interaction. Approaches such as "Supported Conversation for Adults with Aphasia" train the communication partners to use resources such as writing key words, providing written choices, drawing, and using items such as photographs and maps to help the individual with aphasia produce and comprehend conversation.
Locked-in syndrome
StrokeStroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
s that occur in the brainstem may cause profound deficits, including locked-in syndrome
Locked-In syndrome
Locked-in syndrome is a condition in which a patient is aware and awake but cannot move or communicate verbally due to complete paralysis of nearly all voluntary muscles in the body except for the eyes. Total locked-in syndrome is a version of locked-in syndrome where the eyes are paralyzed as...
, in which cognitive, emotional and linguistic abilities remain intact but all or almost all voluntary motor abilities are lost. Most people affected by this type of stroke rely on AAC strategies to communicate, since few recover intelligible speech or functional voice. The AAC strategies used vary with the individual's preferences and motor capabilities which may change over time. As eye movements are most likely to be preserved, eye blinks are frequently used for communication. Low-tech alphabet boards are often introduced immediately to provide the individual with basic communication. Partner-assisted scanning may be used, in which the AAC user signals when the desired letter is named by a communication partner. When vertical and horizontal eye movements are functional, a transparent alphabet board may be used in which the AAC user looks at the desired letter and this is acknowledged by the communication partner. Individuals with locked-in syndrome have difficulty using high-tech devices due to issues with motor control
Motor control
Motor control are information processing related activities carried out by the central nervous system that organize the musculoskeletal system to create coordinated movements and skilled actions...
, vision, memory, alertness
Alertness
Alertness is the state of paying close and continuous attention, being watchful and prompt to meet danger or emergency, or being quick to perceive and act. It is related to psychology as well as to physiology...
and linguistic ability. In particular, a voluntary, reliable and easily controlled muscle movement is necessary to access such a device, such as head, jaw, hand or finger movements. In some individuals, intensive practice, even long after the initial stroke, has been shown to increase the accuracy and consistency of head movements, which can be used to access a communication device.
Amyotrophic lateral sclerosis
Amyotrophic lateral sclerosisAmyotrophic lateral sclerosis
Amyotrophic lateral sclerosis , also referred to as Lou Gehrig's disease, is a form of motor neuron disease caused by the degeneration of upper and lower neurons, located in the ventral horn of the spinal cord and the cortical neurons that provide their efferent input...
(ALS) or Motor Neurone Disease
Motor neurone disease
The motor neurone diseases are a group of neurological disorders that selectively affect motor neurones, the cells that control voluntary muscle activity including speaking, walking, breathing, swallowing and general movement of the body. They are generally progressive in nature, and can cause...
(MND) is a progressive condition which leads to weakness and eventual paralysis
Paralysis
Paralysis is loss of muscle function for one or more muscles. Paralysis can be accompanied by a loss of feeling in the affected area if there is sensory damage as well as motor. A study conducted by the Christopher & Dana Reeve Foundation, suggests that about 1 in 50 people have been diagnosed...
. Approximately 75% of people with ALS are unable to speak by the time of their death. In a procedure known as voice banking, people with ALS may digitally record words and phrases while still able to do so, for later inclusion in a communication device. AAC systems used typically change over time depending on severity of speech impairment, physical status, and the individual's communication needs. Use of augmentative communication strategies generally begins when speaking rate drops to 100 words per minute. In the early stages, AAC may consist of using an alphabet board to cue the listener to the first letter of the word being spoken, and may be used with those less familiar with the individual. In the later stages, AAC often becomes the main communicative method, although familiar conversation partners may still understand some spoken words. Since cognition and vision are typically unaffected in ALS, writing-based systems are preferred to graphic symbols, as they allow the unlimited expression of all words in a language.
The method of access to a communication device depends on the type and severity of the disease. In the spinal form of ALS, the limbs are affected from the onset of the disease; in these cases a head mouse or eye tracking access may be used initially. In the bulbar form, speech is affected before the limbs; here handwriting and typing on keyboard-style devices are frequently the first forms of AAC. AAC users may change access methods as the disease progresses. Low-tech systems, such as eye gazing or partner assisted scanning, are used in situations when electronic devices are unavailable (for example, during bathing) and in the final stages of the disease.
Parkinson's disease
Parkinson's diseaseParkinson's disease
Parkinson's disease is a degenerative disorder of the central nervous system...
is a progressive neurological condition in which dysarthria
Dysarthria
Dysarthria is a motor speech disorder resulting from neurological injury of the motor component of the motor-speech system and is characterized by poor articulation of phonemes...
may develop later in the progression of the disease. Some individuals eventually lose all functional speech. AAC approaches are generally used to supplement and support natural speech. A portable amplifier, for example, may be used to increase the volume of speech and thus its intelligibility. The individual may be taught to point to the first letter of each word they say on an alphabet board, leading to a reduced speech rate and visual cues for the listener to compensate for impaired articulation. Entire words can be spelled out if necessary. In users that have reduced range and speed of movement, a smaller than usual selection display may be preferred. High-tech AAC keyboard speech-generating devices are also used; keyguards may be required to prevent accidental keystrokes caused by the tremor
Tremor
A tremor is an involuntary, somewhat rhythmic, muscle contraction and relaxation involving to-and-fro movements of one or more body parts. It is the most common of all involuntary movements and can affect the hands, arms, eyes, face, head, vocal folds, trunk, and legs. Most tremors occur in the...
typical of the disease. Factors affecting AAC use in Parkinson's disease include motor deficits and cognitive changes; the latter may result in unawareness of their problems with spoken communication.
Multiple sclerosis
Dysarthria is the most common communication problem in individuals with multiple sclerosisMultiple sclerosis
Multiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...
(MS), however, significant difficulties with speech and intelligibility are uncommon. Individuals with MS vary widely in their motor control capacity and the presence of intention tremor
Intention tremor
Intention tremor, also known as cerebellar tremor, is a dyskinetic disorder characterized by a broad, course, and low frequency tremor. The amplitude of an intention tremor increases as an extremity approaches the endpoint of deliberate and visually guided movement...
, and methods of access to AAC technology are adapted accordingly. Visual impairments are common in MS and may necessitate approaches using auditory scanning systems, large-print text, or synthetic speech feedback that plays back words and letters as they are typed.
Dementia
DementiaDementia
Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...
is an acquired, chronic, cognitive impairment
characterized by deficits in memory and other cognitive domains. Communication impairments are partly attributed to memory deficits, and AAC intervention may be used to compensate for deficits and to capitalize on the person's strengths, such as the ability to recognize material they cannot recall. Low-tech devices are generally preferred, such as memory books that include autobiographical information, daily schedules, photographs, and reminders or labels. Several studies have shown positive outcomes in the amount of on-topic conversation and the length of interaction with these approaches. The gains were maintained four months after the training in the use of the memory aids had ceased. High-tech devices with voice output have been found to be less effective; in one study devices resulted in limited topic elaboration/initiation, reduced output and heightened distraction. AAC is also used to enhance the comprehension of those with dementia. The use of augmented listening strategies, such as identifying topics of conversation with pictures, improves the conversational skills of individuals with dementia.
History
Classical Greece
Classical Greece was a 200 year period in Greek culture lasting from the 5th through 4th centuries BC. This classical period had a powerful influence on the Roman Empire and greatly influenced the foundation of Western civilizations. Much of modern Western politics, artistic thought, such as...
, with the first recorded use of augmentative strategies with the deaf. The use of manual alphabets and signs was recorded in Europe from the 16th century, as was the gestural system of Hand Talk used by Native Americans
Native Americans in the United States
Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...
to facilitate communication between different linguistic groups. The first known widely available communication aid was a letter and word-based communication board developed for, and with, F. Hall Roe, who had cerebral palsy. This communication board was distributed in the 1920s by a men's group in Minneapolis.
The modern era of AAC began in the 1950s in Europe and North America, spurred by several societal changes; these included an increased awareness of individuals with communication and other disabilities, and a growing commitment, often backed by government legislation and funding, to develop their education, independence and rights. In the early years, AAC was primarily used with laryngectomy
Laryngectomy
Laryngectomy is the removal of the larynx and separation of the airway from the mouth, nose and esophagus. The laryngectomee breathes through an opening in the neck, a stoma. This procedure is usually performed in cases of laryngeal cancer...
and glossectomy
Glossectomy
A glossectomy is the surgical removal of all or part of the tongue. It is performed in order to curtail malignant growth such as oral cancer. Often only a portion of the tongue needs to be removed, in which case the procedure is called a hemiglossectomy....
cases, and later with individuals with cerebral palsy and aphasia. It was typically only employed after traditional speech therapy had failed, as many felt hesitant to provide non-speech intervention to those who might be able to learn to speak. Individuals with intellectual impairment were not provided with AAC support because it was believed that they did not possess the prerequisite skills for AAC. The main systems used were manual signs, communication boards and Morse code, though in the early 1960s, an electric communication device in the form of a sip-and-puff typewriter controller named the Patient Operated Selector Mechanism (POSM or POSSUM) was developed in the United Kingdom.
From the 1960s onward, sign language increased in acceptance and use in the Deaf community
Deaf culture
Deaf culture describes the social beliefs, behaviors, art, literary traditions, history, values and shared institutions of communities that are affected by deafness and which use sign languages as the main means of communication. When used as a cultural label, the word deaf is often written with a...
, and AAC also came to be viewed as acceptable for those with other diagnoses. Manual sign languages, such as Makaton
Makaton
Makaton is a language programme designed to provide a means of communication to individuals who cannot communicate efficiently by speaking. Makaton has been effectively used with individuals who have cognitive impairments, autism, Down's syndrome, specific language impairment, multisensory...
, were advocated for those with both hearing and cognitive impairments, and later for those with intellectual impairment or autism with normal hearing. Research into whether primate
Primate
A primate is a mammal of the order Primates , which contains prosimians and simians. Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics represent adaptations to life in this challenging three-dimensional environment...
s could learn to sign or use graphic symbols spurred further interest the use of AAC with those with cognitive impairments. The use of Amer-Ind hand signals
Plains Indian Sign Language
The Plains Indian sign languages are various manually coded languages used, or formerly used, by various Native Americans of the Great Plains of the United States of America and Canada...
opened the field to AAC techniques specifically for adult users.
Blissymbols
Blissymbols
Blissymbols or Blissymbolics was conceived as an ideographic writing system called Semantography consisting of several hundred basic symbols, each representing a concept, which can be composed together to generate new symbols that represent new concepts...
were first used in Canada in 1971 to provide communication to those not able to use traditional orthography; their use quickly spread to other countries. With improved technology, keyboard communication devices developed in Denmark, the Netherlands and the US increased in portability; the typed messages were displayed on a screen or strip of paper. By the end of the 1970s, communication devices were being commercially produced, and a few, such as the HandiVoice, had voice output. Countries such as Sweden, Canada and the United Kingdom initiated government-funded services for those with severe communication impairments, including developing centres of clinical and research expertise.
The late 1970s and 1980s saw a massive increase of AAC-related research, publications, and training as well the first national and international conferences. The International Society for Alternative and Augmentative Communication
International Society for Alternative and Augmentative Communication
The International Society for Augmentative and Alternative Communication was founded in May 1983 in East Lansing, Michigan, United States. Its stated purpose is to improve the communication abilities and quality of life of individuals with complex communication needs who use augmentative and...
(ISAAC) was founded in 1983; its members included clinicians, teachers, rehabilitation engineers, researchers, and AAC users themselves. The organization has since played an important role in developing the field through its peer-reviewed journal, conferences, national chapters and its focus on AAC in developing countries. AAC became an area of professional specialization; a 1981 American Speech-Language-Hearing Association
American Speech-Language-Hearing Association
The American Speech–Language–Hearing Association is a professional association for speech–language pathologists, audiologists, and speech, language, and hearing scientists in the United States and internationally...
position paper, for example, recognized AAC as a field of practice for speech-language pathologists. At the same time, AAC users and family members played an increasing prominent role in the development of knowledge of AAC through their writing and presentations, by serving on committees and founding advocacy organizations.
From the 1980s, improvements in technology led to a greatly increased number, variety, and performance of commercially available communication devices, and a reduction in their size and price. Alternative methods of access such eye pointing or scanning became available on communication devices. Speech output possibilities included digitized and synthesized speech, with text-to-speech options available in German, French, Italian, Spanish, Swedish and Ewe
Ewe language
Ewe is a Niger–Congo language spoken in Ghana, Togo and Benin by approximately six million people. Ewe is part of a cluster of related languages commonly called Gbe, spoken in southeastern Ghana, Togo, and parts of Benin. Other Gbe languages include Fon, Gen, Phla Phera, and Aja...
. AAC services became more holistic, seeking to develop a balance of aided and unaided strategies with the goal of improving functioning in the person's daily life, and greater involvement of the family. Increasingly, individuals with acquired conditions such as amyotrophic lateral sclerosis, Parkinson's disease, head injury, and locked-in syndrome, received AAC services. In addition, with the challenge to the notion of AAC prerequisites, those with severe to profound intellectual impairments began to be served. Courses on AAC were developed for professional training programs, and literature such as textbooks and guides were written to support students, clinicians and parents.
The 1990s brought a focus on greater independence for people with disabilities, and more inclusion in mainstream society . In schools, students with special needs
Special needs
In the USA, special needs is a term used in clinical diagnostic and functional development to describe individuals who require assistance for disabilities that may be medical, mental, or psychological. For instance, the Diagnostic and Statistical Manual of Mental Disorders and the International...
were placed in regular classrooms rather than segregated settings, which led to an increased use of AAC as a means of improving student participation in class. Interventions became more collaborative and naturalistic, taking place in the classroom with the teacher, rather than in a therapy room. Facilitated communication
Facilitated communication
Facilitated communication is a process by which a facilitator supports the hand or arm of a communicatively impaired individual while using a keyboard or other devices with the aim of helping the individual to develop pointing skills and to communicate...
– a method by which a facilitator physically and emotionally supports a person with severe communication needs as they type on a keyboard or letter board – received wide attention in the media and in the field. The question of the authorship made the approach controversial; most of the subsequent research indicated that the facilitators were unknowingly influencing the messages typed. As a result, professional organizations and AAC researchers and clinicians have not typically accepted facilitated communication.
Rapid progress in hardware and software
Computer software
Computer software, or just software, is a collection of computer programs and related data that provide the instructions for telling a computer what to do and how to do it....
development continued, including projects funded by the European Community. The first commercially available dynamic screen speech generating devices were developed in the 1990s. At the same time synthesized speech was becoming available in more languages. Software programs were developed that allowed the computer-based production of communication boards. High-tech devices have continued to reduce in size and weight, while increasing accessibility and capacities. Modern communication devices can also enable users to access the internet and some can be used as environmental control devices
Environmental control device
An environmental control system is a form of electronic assistive technology which enables people with significant disabilities to independently access equipment in their environment e.g. home or hospital....
for independent access of TV, radio, telephone etc.
External links
- ISAAC – International Society for Augmentative and Alternative Communication
- AAC-RERC – Augmentative and Alternative Communication Rehabilitation Engineering Research Centers
- USSAAC – United States Society for Augmentative and Alternative Communication
- Communication Matters
- AAC Institute
- ASHA AAC Information
- Rehabilitation Engineering and Assistive Technology Society of North America