It is estimated that from 8 to 12 out of every 1000 individuals have a communication disorder severe enough to require the use of augmentative and alternative communication (AAC) intervention (Beukelman and Ansel, 1995). A large percentage of these individuals are children with spoken language disorders and a range of etiologies. Manual signs, communication boards, and computers with voice output have been developed to provide a means by which children with severe spoken language disorders can acquire language and communication skills. AAC is a language intervention approach.

The American Speech-Language-Hearing Association defines AAC as an area of research, clinical, and educational practice that attempts to compensate, either permanently or temporarily, for the impairment and disability patterns of individuals with severe expressive and receptive communication disorders that affect spoken, gestural, and/or written modes of communication. AAC is comprised of a system of four integrated components: symbols, aids, techniques, and strategies. The first component, symbols, are visual, auditory, and/or tactile, used to represent vocabulary and described as either aided or unaided. An aided AAC symbol employs the use of an external medium (e.g., photographs, pictures, line drawings, objects, Braille, or written words), while an unaided AAC symbol utilizes the AAC user's body (e.g., sign language, eye pointing, vocalizations). Aids are the second component; an aid is an object used to transmit or receive messages and includes, for example, communication boards, speech-generating devices, or computers. A technique, the third component, is the approach or method used for generating or selecting messages as well as the types of displays used to view messages. Messages may be generated or selected via direct selection or scanning. Direct selection permits a child to communicate messages from a large set of options using, for example, manual signing or pointing with a finger or headstick to a symbol. Scanning is used when message choices are presented to the child in a sequence and the child makes his or her selection by linear scanning, row-column scanning, or encoding. Displays may be either fixed (i.e., the symbol remains the same before and after activation) or dynamic (i.e., the symbol visually changes with its selection). Finally, strategies, the fourth component, are the specific intervention approaches in which AAC symbols, aids, and techniques are used to facilitate or develop language and communication skills via AAC (see ASHA, 1991; ASHA, in preparation, for complete definitions).

The role an AAC system plays in a particular child's life will vary depending on the type and severity of the child's language disorder. Children who use AAC include those individuals who present with congenital disorders as well as those individuals with an acquired language disorder. Children with congenital language disorders include children with cerebral palsy, dual sensory impairments, developmental apraxia of speech, language learning disabilities, mental retardation, autism, and pervasive developmental disorders. Acquired language disorders may include traumatic brain injury (TBI) and a range of other etiologies (e.g., sickle cell anemia) that affect language skills.

Children with language disorders who can employ AAC systems may range in age from toddlers to adolescents (Romski, Sevcik, and Forrest, 2001). The role AAC plays in language intervention depends on the child's individual communication needs. It is not restricted to use with children who do not speak at all and may benefit children with limited or unintelligible speech as well as those young children who may be at significant risk for failure to develop spoken communication. There are no exclusionary criteria or prerequisites for learning to use an AAC system (National Joint Committee, in preparation). Every child can communicate! Communication is defined in the broadest sense as “any act by which one person gives to or receives from another person information about that person's needs, desires, perceptions, knowledge, or affective states” (National Joint Committee, 1992). The modes by which children can communicate range along a representational continuum from symbolic (e.g., spoken words, manual signs, arbitrary visual-graphic symbols, printed words) to iconic (e.g., actual objects, photographs, line drawings, pictographic visual-graphic symbols) to nonsymbolic (e.g., signals such as crying or physical movement) (Sevcik, Romski, and Wilkinson, 1991). AAC interventions incorporate a child's full communication abilities, including vocalizations, gestures, manual signs, communication boards, and speech-generating devices. Even if a child uses some vocalizations and gestures, AAC systems can augment communication with familiar and unfamiliar partners across multiple environments. Some children with severe spoken language disorders who have no conventional way to communicate may express their communicative wants and needs in socially unacceptable ways, such as through aggressive or destructive, self-stimulatory, and/ or perseverative means. AAC systems can replace these unacceptable means with conventional communication (Mirenda, 1997). AAC is truly multimodal, permitting a child to use every mode possible to communicate messages and ideas.

While AAC is an intervention approach, a team assessment is needed to describe, within a functional context, the child's language and communicative strengths and weaknesses and to determine what type of AAC system will permit the child to develop language and communication skills in order to participate in daily activities. AAC assessment is an ongoing process and includes a characterization of the child's current communication development (i.e., speech comprehension skills, communication modes), an inventory of the child's environments including partners and opportunities for communication, and a description of the child's physical abilities to access communication, including vision, hearing, and fine and gross motor skills. Fine and gross motor access includes physical access to an AAC system and in some cases seating and positioning options for optimal communication. A collaborative team approach to AAC service delivery incorporates families and a range of professional disciplines including, though not limited to, speech-language pathologists, general and special educators, and physical and occupational therapists. AAC abilities may change over time, although sometimes very slowly, and thus the AAC system selected for the present may need to be modified as a child grows and develops.

Not surprisingly, standardized psychological and speech and language assessment batteries are often difficult to employ with children with severe spoken language disorders because of the severity of their oral communication impairments. These assessments may not reveal an accurate picture of a child's abilities since many of these assessments are language-based and may be biased against a child who cannot speak. Often, the children are unable to obtain basal scores on such tests or their scores are so far below those of their chronological age peers that converting a raw score into a standard score is not possible. Systematic behavioral observation within everyday environments and informal measures that inventory and describe communication demands in these settings are employed to measure the communication skills of children who will employ AAC systems rather than standardized tests within isolated settings.

For most children who use AAC systems, language and communication development is the most important goal. Like all language and communication interventions, the long-term goal is to facilitate meaningful communication interactions during daily activities and routines. Goals should not only focus on the technological means of access the child uses, but on the development of language and effective communication skills. Depending on the child's current language and communication skills, goals may range from developing a basic vocabulary of single symbols or signs to express basic wants and needs to using sentences of symbols and signs to convey complex communicative messages (Reichle, York, and Sigafoss, 1991; Romski and Sevcik, 1996). It is essential that AAC system use take place in inclusive environments. The literature strongly suggests that AAC systems can be embedded effectively within ongoing events of everyday life (Beukelman and Mirenda, 1998). Using AAC systems in inclusive settings requires that the team work together to ensure that the child has access to his or her AAC device throughout the day and that all adults and children who may interact with the child serve to support the child's communications as needed.

One frequently asked question is whether the use of AAC systems hinders speech development. Developing natural speech and literacy abilities are extremely important goals of AAC intervention. The empirical evidence suggests that AAC system use may result in increases in vocalizations and in some cases the development of intelligible speech (Beukelman and Mirenda, 1998). There is no evidence to suggest that AAC hinders or halts speech development. The use of AAC systems may also facilitate the development of early literacy skills and later reading.

In summary, for children with severe spoken communication disabilities, the AAC assessment is an ongoing process that includes information about the child's communication development, the child's environments, and the child's physical abilities. Children with severe language disorders who use AAC systems can demonstrate communication achievements far beyond traditional expectations. Recommended assessment and intervention practices are continuing to develop. The use of appropriate AAC systems enables the child to communicate effectively at home, school, play, and work. In addition to the development of communication skills, AAC increases social interactions with family and friends and participation in life activities.

See also augmentative and alternative communication approaches in children.