Human interaction relies fundamentally on the capacity to share intent, exchange complex ideas, and establish relational bonds through symbolic expression. For millions of individuals worldwide who experience temporary or lifelong impairments in spoken language production, augmentative communication provides an indispensable framework of multimodal strategies, specialized tools, and clinical interventions designed to unlock expressive potential and ensure equitable participation across all domains of life.
Augmentative Communication
1. Concise Definition
Augmentative communication refers to an interdisciplinary area of clinical practice, technological innovation, and research dedicated to supplementing, enhancing, or supporting natural speech and gestural expression in individuals with severe speech, language, or communication impairments. Rather than serving merely as a surrogate for spoken discourse, augmentative systems provide dynamic semiotic platforms that maximize an individual’s residual linguistic skills while introducing alternative pathways for interactive exchange.
In modern clinical and academic nomenclature, the discipline is formally integrated within the broader paradigm of augmentative and alternative communication (AAC). Within this dual conceptualization, augmentative strategies explicitly denote techniques that support, clarify, or expand speech that is unintelligible, fragmented, or physically fatiguing, whereas alternative strategies replace spoken communication entirely when oral articulation is absent or clinically non-viable. In everyday practice, augmentative communication encompasses low-technology tangible boards, specialized symbol vocabularies, high-technology digitized voice output devices, and bespoke neuro-computational interfaces.
2. Etymology & Linguistic Origin
The term augmentative is derived from the Late Latin verbal stem augmentare, signifying “to increase, enlarge, or strengthen,” which itself stems from the classical Latin noun augmentum (“an increase, growth”), originating from the Proto-Indo-European root *aug-, meaning “to increase” or “to enlarge.” The word entered Middle English through the Old French augmenter during the fourteenth century, retaining its foundational denotation of supplementing or reinforcing an existing substrate without implying total substitution.
The companion noun communication traces its heritage to the Latin communicare, meaning “to share, impart, make common, or unite,” constructed from the prefix com- (“together”) and the noun munus (“gift, service, duty, or office”). The union of these two distinct lexical roots in speech-language pathology and special education occurred during the 1970s and 1980s. Clinicians and researchers deliberately combined them to articulate a philosophical paradigm shift: individuals with severe communicative disorders were no longer viewed as lacking communicative agency, but rather as requiring specific compensatory structures to expand, amplify, and realize their inherent communicative intent.
3. Pronunciation & Grammatical Form
The standard phonetic transcription of augmentative communication in Received Pronunciation (British English) is /ɔːɡˈmɛntətɪv kəˌmjuːnɪˈkeɪʃn/, while in General American English it is pronounced /ɔːɡˈmɛntətɪv kəˌmjuːnəˈkeɪʃən/ or /ɔːɡmɛnˈteɪtɪv kəˌmjuːnəˈkeɪʃən/. Primary syllable stress in “augmentative” falls upon the second syllable (-men-) or, in alternate North American dialects, the third syllable (-ta-), while “communication” consistently receives primary stress on the penultimate syllable (-ca-).
Grammatically, “augmentative communication” functions as a composite nominal phrase (noun phrase). Within this construction, “augmentative” serves as a classifying adjective modifying the non-count abstract noun “communication.” Syntactically, it frequently appears as an attributive nominal adjunct within compound terms such as augmentative communication system, augmentative communication specialist, or augmentative communication intervention. In clinical records and scholarly literature, it is routinely represented by the acronym AAC, which serves as a mass noun or as a prenominal modifier (e.g., “AAC assessment,” “AAC user”).
4. Detailed Conceptual Explanation
Augmentative communication operates at the critical intersection of linguistics, neuroscience, assistive technology, biomedical engineering, and developmental psychology. Fundamentally, communication involves formulating, transmitting, receiving, and decoding messages across dynamic social environments. When neurological trauma, congenital physical impairments, or developmental conditions compromise the motor control required for phonation, resonance, and articulation, the speech chain breaks down. Augmentative communication bypasses or mitigates these mechanical bottlenecks by decoupling linguistic formulation from peripheral motor execution, providing external symbolic systems and transmission media through which linguistic meaning can be materialized.
The theoretical scope of augmentative communication rests upon the premise that communication is multimodal. Typical human communicators effortlessly combine spoken words, prosody, facial expressions, vocalizations, manual gestures, and orthography to convey meaning depending on the interpersonal context. Augmentative communication formalizes, scaffolds, and enriches this multimodal repertoire. An individual might utilize vocalizations to signal distress, eye gaze toward a graphic symbol board to select a specific conversational topic, a dedicated digital tablet to formulate syntactically complex utterances, and natural gestures to acknowledge a peer. Therefore, augmentative communication is never a static apparatus; it is an organized, personalized matrix of semiotic resources tailored to the communicative opportunities and physical abilities of the individual.
Boundaries within the discipline differentiate pure augmentative methodologies from broader assistive technologies and purely rehabilitative therapy. Assistive technology encompasses any item, piece of equipment, or software used to enhance functional capabilities of people with disabilities, including power wheelchairs, environmental control units, and screen-reading software. Augmentative communication constitutes a distinct linguistic subcategory of assistive technology focused specifically on face-to-face and telecommunicative human interaction. Furthermore, augmentative communication differs fundamentally from traditional restorative speech therapies. While restorative therapies seek to remediate the underlying physiological mechanisms of speech production, augmentative communication acts concurrently or proactively to establish functional communicative competence immediately, rejecting the historically harmful notion that spoken speech must be abandoned or fully mastered before alternative symbolic tools can be introduced.
5. Historical Development
The origins of augmentative communication as a recognized clinical and scientific discipline date to the mid-twentieth century, evolving through distinct ideological and technological eras. Prior to the 1950s, individuals experiencing profound motor speech impairments—such as those secondary to severe cerebral palsy, amyotrophic lateral sclerosis (ALS), or brainstem strokes—were largely deemed ineducable or left to rely on rudimentary idiosyncratic gestures. The earliest documented clinical efforts emerged during the 1950s and 1960s, driven by visionary practitioners who crafted rudimentary communication displays, such as wooden alphabet boards and rotating circular spelling wheels, to assist veterans recovering from traumatic brain injuries and post-polio respiratory paralysis.
The 1970s marked an intellectual watershed characterized by the systematic introduction of graphic symbol systems. Shirley McNaughton and her interdisciplinary team at the Ontario Crippled Children’s Centre (now Holland Bloorview Kids Rehabilitation Hospital) pioneered the application of Blissymbolics—a semantically transparent, visual-ideographic language originally developed by Charles Bliss—for non-speaking children with cerebral palsy. This breakthrough demonstrated empirically that children with profound speech disorders could acquire functional literacy and syntactic mastery when liberated from speech production constraints. Concurrently, pioneering clinicians such as David Beukelman, Pat Mirenda, and Lyle Lloyd began formulating the academic curricula and assessment paradigms that laid the groundwork for modern clinical speech-language pathology.
During the 1980s and 1990s, the field underwent rapid institutionalization and technological disruption. The International Society for Augmentative and Alternative Communication (ISAAC) was founded in 1983, catalyzing global collaboration, peer-reviewed clinical research, and policy advocacy. The microprocessor revolution spurred the development of dedicated, electronic speech-generating devices (SGDs), pioneered by biomedical innovators such as Toby Churchill, who developed the Lightwriter, and companies like the Prentke Romich Company (PRC) and Dynavox. High-profile advocates, most notably theoretical physicist Stephen Hawking, who relied on the Equalizer and later customized computerized systems, dismantled societal misconceptions regarding the intellectual capacity of non-speaking individuals.
In the twenty-first century, augmentative communication experienced a consumer technology revolution. The emergence of mainstream commercial tablets, accessible mobile operating systems, and dedicated applications democratized access to communication software, significantly lowering financial barriers for families and clinical providers. Contemporary research now focuses on artificial intelligence, cloud-based predictive text algorithms, automated natural language processing, and non-invasive brain-computer interfaces (BCIs), which allow individuals with locked-in syndrome to control communication software through neural electrical potentials alone.
6. Theoretical Foundations
Augmentative communication is anchored in foundational psycholinguistic, sociocultural, and cognitive models. Foremost among these is the Communicative Competence Framework formulated by Janice Light in 1989 and comprehensively updated in subsequent literature. Light conceptualized that successful communication for AAC users does not merely depend on technological mastery, but rather on the dynamic intersection of four distinct competencies: linguistic, operational, social, and strategic.
Linguistic competence involves mastery of both the native spoken language of the community and the internal symbolic language of the augmentative system (e.g., pictograms, bliss symbols, or orthography). Operational competence denotes the physical, sensory, and technical skills necessary to navigate and manipulate the communication medium, whether that requires activating a mechanical switch, coordinating eye gaze across a digital screen, or turning physical pages. Social competence encapsulates pragmatic communicative rules, including conversational turn-taking, cohesion, sociolinguistic status adjustments, and initiating or terminating interactions appropriately. Strategic competence refers to the compensatory mechanisms employed by the user to overcome communicative breakdowns, mitigate slow transmission rates, or manage unfamiliar communication partners.
Complementing this model is Lev Vygotsky’s Sociocultural Theory of cognitive development, specifically the concepts of semiotic mediation and the Zone of Proximal Development (ZPD). Augmentative communication displays function precisely as cultural and semiotic tools that mediate higher-order mental functions. By externalizing cognitive and linguistic structures into visible, selectable symbols, communicative scaffolds allow users to engage in interpersonal interactions that would otherwise exceed their autonomous expressive abilities. Modern clinical methodologies such as Aided Language Stimulation (ALgS) draw directly upon Vygotskian principles: competent partners actively point to symbols on the user’s system while speaking, thereby immersing the learner in a rich linguistic environment that models functional use within authentic communicative transactions.
7. Key Components, Types & Dimensions
An augmentative communication system is best conceptualized as an integrated constellation of four core components: symbols, aids, access techniques, and communicative strategies. Within these components, systems are categorized across several structural dimensions:
- Unaided vs. Aided Communication: Unaided systems rely exclusively on the user’s anatomical body without external equipment, comprising natural speech, idiosyncratic vocalizations, facial expressions, manual sign languages (e.g., ASL or BSL), and universal gestures. Aided systems mandate external tools, objects, or physical equipment, spanning physical graphic displays to advanced electronic hardware.
- Technology Continuum (No-Tech, Low-Tech, High-Tech): No-tech approaches utilize existing physical materials without specialized fabrication; low-tech (or light-tech) solutions involve static physical tools requiring no internal electricity, such as laminated picture boards, eye-gaze frames (E-TRAN), and communication books; high-tech systems incorporate electronic circuitry, microprocessors, and digital displays, functioning as specialized speech-generating devices (SGDs) that synthesize or digitize human voice output.
- Symbolic Representation Systems: Systems vary according to iconicity—the perceived association between a symbol and its referent. These include transparent physical objects, miniature miniatures, textured tactile symbols, photographic prints, line drawings (e.g., Mayer-Johnson Picture Communication Symbols), semantic compaction systems (e.g., Minspeak), and abstract orthographic text.
- Selection and Access Techniques: Direct selection occurs when the user indicates a specific symbol directly using a finger, toe, physical pointer, optical head tracker, or infra-red eye-gaze tracking camera. Indirect selection (scanning) is deployed when motor impairments preclude direct targeting; items are illuminated or vocalized sequentially or by rows and columns, and the user activates a microswitch via a single repeatable physical movement (e.g., head tilt, knee twitch, sip-and-puff mechanism) when the desired item is highlighted.
- Dynamic vs. Static Displays: Static displays maintain fixed symbols across physical or printed boards, whereas dynamic displays utilize electronic touchscreens that alter visual menus automatically based on user navigation, allowing access to thousands of linguistic items across hierarchical semantic categories.
8. Examples & Illustrative Cases
The practical execution of augmentative communication is highly idiosyncratic, varying according to an individual’s motoric capabilities, developmental trajectory, and lifestyle demands. Below are illustrative clinical prototypes reflecting different applications across the lifespan:
Case Illustration A: Pediatric Developmental Disorder
Leo, a 5-year-old child diagnosed with non-speaking Autism Spectrum Disorder, demonstrates intact intent to request reinforcing objects but experiences profound emotional frustration due to an inability to articulate words. A clinical team initiates an intervention utilizing the Picture Exchange Communication System (PECS) before transitioning him to a dynamic-display tablet running a robust, core-vocabulary symbol-based application. Leo selects graphic pictograms representing high-frequency verbs and nouns (“want,” “go,” “outside,” “bubbles”). By pairing visual modeling with verbal output, Leo’s communication rate increases, behavioral outbursts drop by over eighty percent, and he begins producing spontaneous dual-symbol combinations.
Case Illustration B: Adult-Onset Neurodegenerative Condition
Eleanor, a 62-year-old university professor, receives a diagnosis of Amyotrophic Lateral Sclerosis (ALS), a progressive motor neuron disease that inevitably degrades bulbar muscular function. Anticipating total loss of voluntary motor function and speech intelligibility, Eleanor participates in proactive “message banking” and “voice banking,” recording hundreds of personally meaningful phrases and digitizing her vocal acoustic signature. As she loses upper-limb mobility, clinicians equip her with a high-definition eye-tracking computer mounted to her wheelchair. By fixating her gaze on an on-screen keyboard equipped with semantic prediction software, Eleanor continues delivering academic lectures, drafting emails, and conversing with family members using her synthesized, natural-sounding voice.
Case Illustration C: Acute Hospital Care and Temporary Impairment
Marcus, a 34-year-old trauma patient admitted to an intensive care unit following a vehicular collision, undergoes an emergency tracheostomy and requires invasive mechanical ventilation. Fully conscious, cognitively intact, but temporarily aphonic and physically exhausted, Marcus experiences profound acute distress due to an inability to communicate with hospital staff. The clinical speech-language pathologist provides a clear acrylic eye-gaze communication board (E-TRAN) containing alphabet clusters and vital medical pain scales. By directing his gaze to specific quadrants, Marcus immediately reports localized thoracic pain and indicates urgent medication needs, mitigating clinical miscommunication and improving critical care outcomes.
9. Measurement & Assessment
The assessment of individuals requiring augmentative communication is not an isolated psychometric testing event, but an iterative, multidimensional process. The prevailing international standard is the Participation Model, formalized by Beukelman and Mirenda. This framework shifts focus away from isolated clinical deficits toward assessing the user’s specific participation patterns compared to non-disabled peers, identifying both “opportunity barriers” and “access barriers.”
Assessment encompasses several systematic stages:
- Opportunity Barrier Analysis: Evaluates external environmental constraints, including policy barriers (legislative exclusions), practice barriers (routines within educational or care facilities), attitude barriers (discriminatory beliefs held by staff or peers), and knowledge/skill barriers (caregivers lacking training on how to operate or model on the device).
- Access Barrier Assessment: Assesses the internal capabilities and limitations of the user, requiring rigorous clinical profiling across sensory-perceptual acuity (vision and hearing evaluations), motor functioning (range of motion, postural stability, endurance, and seating positioning evaluated in collaboration with occupational and physical therapists), cognitive capacities, and linguistic competence.
- Feature Matching: The fundamental clinical methodology wherein the identified cognitive, sensory, and motor needs of the client are systematically matched against the technical features of communication tools (e.g., display size, weight, access methods, vocabulary organization, visual layout, and synthesized voice properties).
- System Usability and Functional Outcomes: Clinicians monitor progress using standardized qualitative and quantitative tools such as the Psychosocial Impact of Assistive Devices Scale (PIADS), the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST), and the Communication Matrix, an assessment framework mapping expressive behaviors across seven developmental communicative levels.
10. Applications & Practical Significance
Augmentative communication generates profound transformative effects across clinical, educational, vocational, and sociopolitical domains. In educational settings, the integration of robust augmentative tools dismantles systemic segregation. Historically, non-speaking students were routinely placed in non-academic care environments under the false assumption that spoken language is a prerequisite for intellectual engagement. Contemporary augmentative strategies allow students to demonstrate knowledge, participate in inclusive academic curricula, acquire literacy skills, and interact socially with peer groups, honoring educational mandates established under the Individuals with Disabilities Education Act (IDEA) and the United Nations Convention on the Rights of Persons with Disabilities (CRPD).
From a public health and biomedical perspective, augmentative communication dramatically reduces medical errors and patient adverse events. In acute and residential care contexts, non-vocal patients face significantly elevated risks of hospital readmission, unrecognized pain, medication errors, and physical maltreatment. Supplying accessible visual and electronic communication tools within hospital systems mitigates communication breakdowns, empowers patients to provide informed consent, and facilitates accurate differential diagnosis of internal medical crises.
Furthermore, augmentative communication is indispensable to fundamental human rights and self-determination. The American Speech-Language-Hearing Association (ASHA) and the National Joint Committee for the Communication Needs of Persons with Severe Disabilities (NJC) codified the “Communication Bill of Rights.” This landmark charter asserts that every human being holds an inherent right to affect the conditions of their existence through communication, including the right to request, refuse, express preferences, access information, maintain interpersonal intimacy, and reject unwanted interventions. Augmentative communication serves as the physical vehicle through which these fundamental human rights are actualized.
11. Research & Empirical Evidence
A substantial body of empirical research supports the clinical efficacy of augmentative communication across the developmental and acquired lifespan. One of the most critical and extensively researched questions is whether introducing augmentative tools inhibits, impedes, or discourages natural speech production. In an influential meta-analysis by Millar, Light, and Schlosser (2006), the researchers examined the effects of AAC interventions on speech production in individuals with developmental disabilities. The findings conclusively refuted the myth of speech inhibition: following AAC adoption, eighty-nine percent of participants demonstrated measurable increases in natural speech production, while eleven percent showed no change, and zero percent exhibited a regression in spoken language. Augmentative communication reduces the cognitive and motoric pressures of spontaneous articulation, effectively scaffolding spoken speech development through simultaneous auditory and visual reinforcement.
Research conducted by Cathy Binger, Janice Light, and colleagues has underscored the crucial role of communication partner training. Studies demonstrate that supplying an individual with a high-tech device produces negligible clinical improvements if the surrounding communicative environment remains unaccommodating or untrained. Interventions that instruct educational staff, parents, and healthcare aides in Aided Language Stimulation (modeling symbol selection while speaking) and expectant delay techniques lead to statistically significant gains in vocabulary acquisition, mean length of utterance (MLU), and spontaneous communicative initiations among AAC users.
In neurodegenerative research, studies spearheaded by Melanie Fried-Oken and colleagues have documented the clinical impact of timely, proactive augmentative interventions for individuals with ALS and primary progressive aphasia. Implementing voice banking protocols prior to the critical decline of bulbar motor function directly correlates with enhanced long-term psychological wellbeing, preserved personal identity, and sustained social engagement throughout the terminal phases of degenerative illness.
12. Cultural & Cross-Cultural Considerations
Communication is inextricably bound to cultural values, familial customs, and sociolinguistic traditions. A persistent limitation within augmentative communication research and commercial tool development has been an implicit Anglo-centric, Western bias. Many commercially standard systems reflect individualistic communication patterns, emphasizing direct requests, personal autonomy, and declarative assertions. In collectivist cultural traditions, however, communicative exchanges may prioritize relational harmony, deference to familial hierarchy, non-verbal contextual cues, and indirect discourse, patterns that must be thoughtfully integrated into the user’s symbolic lexicon.
Linguistic diversity presents significant structural challenges. Most commercial high-tech systems are originally designed for English, a language characterized by relatively simple morphosyntax and rigid subject-verb-object word order. Applying these pre-programmed architectures directly to agglutinative, polysynthetic, or morphologically complex languages (such as Turkish, Finnish, or Arabic) often leads to significant communicative inefficiencies, as users cannot easily inflect base root morphemes without exhausting motor effort. Moreover, the graphical design of symbols requires careful localization: line drawings depicting gestures (such as thumbs-up or waving), clothing, dietary items, and interpersonal familial structures often convey unintentional or offensive connotations when introduced without community cultural validation.
13. Criticisms, Debates & Limitations
Despite extraordinary advancements, augmentative communication remains characterized by persistent practical controversies, technical bottlenecks, and clinical debates. A central systemic challenge is the stubbornly elevated rate of “device abandonment.” Empirical studies show that between thirty and fifty percent of high-tech devices prescribed to individuals with disabilities are ultimately abandoned or underutilized. Factors contributing to abandonment include inadequate initial feature-matching, excessive mechanical or visual complexity, cumbersome device weight, high maintenance burdens for caregivers, systemic lack of partner training, and social stigma associated with using a visibly conspicuous medicalized apparatus.
The field has also faced profound ethical and scientific crises, most notoriously surrounding unvalidated, pseudoscientific methods such as “Facilitated Communication” (FC) and its contemporary permutations (e.g., the Rapid Prompting Method). In FC, a facilitator physically supports the arm, hand, or wrist of an individual with severe communication disorders while they point to an alphabet display. Controlled, double-blind scientific studies repeatedly demonstrated that the messages produced were authored entirely by the facilitators via subconscious motor cues (the ideomotor effect), rather than by the individuals themselves. Prestigious international bodies, including ASHA, the American Psychological Association (APA), and ISAAC, have issued definitive position statements rejecting Facilitated Communication as an unscientific practice that violates the communicative agency and human rights of vulnerable individuals.
An additional ongoing clinical tension exists between low-tech and high-tech prioritization. Commercial marketing and parental pressures often demand immediate procurement of high-tech speech-generating devices, occasionally bypassing foundational communicative competencies. Conversely, excessive reliance on rudimentary, static low-tech systems can severely cap a user’s expressive potential. Modern clinical best practices mandate a comprehensive multimodal compromise: high-tech systems must be paired with low-tech redundancies (e.g., laminated boards) to guarantee functional communication during device malfunction, water exposure, or physical fatigue.
14. Related Terms & Distinctions
Understanding augmentative communication requires analyzing its boundaries and distinctions relative to adjacent clinical, technical, and linguistic concepts:
- Augmentative vs. Alternative Communication: Augmentative strategies supplement, complement, or clarify residual or partially intact speech. Alternative strategies serve as the primary, complete replacement for speech in individuals who are entirely unable to articulate vocal sounds.
- Assistive Technology (AT): An umbrella construct covering any technical device or service designed to sustain or expand overall functional capacity for individuals with disabilities. Augmentative communication is a specialized subset of assistive technology focused strictly on human interactive communication.
- Speech-Generating Device (SGD): An electronic high-tech aid that utilizes digitized (recorded) or synthesized (text-to-speech) acoustic output to vocalize messages. An SGD represents a single technological manifestation within an augmentative communication system, not the system itself.
- Manual Sign Languages: Fully natural, linguistically complete visuospatial languages (such as American Sign Language or British Sign Language) with independent grammar and syntax. While manual signing can serve as an unaided augmentative strategy, formal sign languages are distinct linguistic systems historically belonging to Deaf culture rather than clinical compensatory systems designed for disordered motor-speech execution.
- Communicative Competence vs. Linguistic Competence: Linguistic competence denotes abstract knowledge of vocabulary and grammar; communicative competence encompasses the pragmatic, functional, and strategic application of that linguistic knowledge within real-world interpersonal interactions.
15. Summary & Key Takeaways
Augmentative communication represents a transformative paradigm that bridges technological innovation, semiotic theory, and clinical rehabilitation to ensure functional communication for individuals with severe speech impairments. By synthesizing unaided modalities with sophisticated low- and high-tech aided systems, the field provides individuals with expressive pathways that transcend peripheral physiological barriers.
Effective augmentative interventions depend not simply on hardware procurement, but on comprehensive feature-matching, systematic modeling within authentic environments, rigorous communication partner training, and respect for cultural nuances. As neuro-computational interfaces, artificial intelligence, and eye-tracking technologies continue to evolve, the field advances closer to realizing its foundational commitment: affirming that every person, irrespective of physical or neurological diversity, retains an absolute right to express their authentic voice, shape their personal destiny, and engage meaningfully with the global community.
References
- American Speech-Language-Hearing Association. (2004). Roles and responsibilities of speech-language pathologists with respect to augmentative and alternative communication: Position statement. https://www.asha.org/policy/PS2004-00102/
- Beukelman, D. R., & Light, J. C. (2020). Augmentative & alternative communication: Supporting children and adults with complex communication needs (5th ed.). Paul H. Brookes Publishing Co.
- Binger, C., & Light, J. (2007). The effect of aided AAC modeling on the expression of multi-symbol messages by preschoolers who use AAC. Augmentative and Alternative Communication, 23(1), 30–43. https://doi.org/10.1080/07434610600807470
- Light, J. (1989). Toward a definition of communicative competence for individuals using augmentative and alternative communication systems. Augmentative and Alternative Communication, 5(2), 137–144. https://doi.org/10.1080/07434618912331275126
- Light, J., & McNaughton, D. (2014). Communicative competence for individuals who require augmentative and alternative communication: A new definition for a new era of communication? Augmentative and Alternative Communication, 30(1), 1–18. https://doi.org/10.3109/07434618.2014.885080
- Millar, D. C., Light, J. C., & Schlosser, R. W. (2006). The impact of augmentative and alternative communication intervention on speech production of individuals with developmental disabilities: A research review. Journal of Speech, Language, and Hearing Research, 49(2), 248–264. https://doi.org/10.1044/1092-4388(2006/021)
- National Joint Committee for the Communication Needs of Persons With Severe Disabilities. (1992). Guidelines for meeting the communication needs of persons with severe disabilities. ASHA, 34(Suppl. 7), 1–8.
- Schlosser, R. W., & Wendt, O. (2008). Effects of augmentative and alternative communication intervention on speech production in children with autism: A systematic review. American Journal of Speech-Language Pathology, 17(3), 212–230. https://doi.org/10.1044/1058-0360(2008/021)