AAC: what it is and what the research shows
What augmentative and alternative communication covers, what it is used for, whether it holds speech back, and how thin the research gets once the children it studies become adults.
What augmentative and alternative communication is, what people use it for, whether it stops speech, and why the research is thin once children grow up.
What AAC is Established
AAC stands for augmentative and alternative communication. It is the term for the ways people communicate when speech is hard or not available.1 Augmentative methods add to speech; alternative methods stand in for it. Some people use AAC all the time, some now and then, and some only for a while, such as after surgery.1
The methods run from unaided to high-tech. Gestures, signing, pointing to pictures and words, spelling, writing and picture exchange systems need little or no equipment. Speech-generating devices and apps on a tablet or phone sit at the other end.1,2,3 People often use more than one tool, and what works for one person may not work for another.1
In the autistic AAC research, the two most-used tools are speech-generating devices and low-tech picture exchange.2 PECS, the Picture Exchange Communication System, is a common low-tech picture system, in which a person hands over or points to a picture to communicate.2
AAC stands for augmentative and alternative communication.1 It means the ways people communicate when talking is hard or not possible. Some people use AAC all the time. Some use it now and then. Some use it only for a short time, such as after surgery.1
AAC can be simple or high-tech. You can point to pictures, use signs, spell, or write. You can use a talking device or an app on a tablet or phone.1,2,3 Many people use more than one kind.
In autism research, the most common tools are talking devices and picture exchange.2 PECS is a low-tech picture system. A person gives or points to a picture to tell someone something.2
The definition comes from clinical guidance and the name covers the same methods across the AAC reviews. This section describes what the term includes, not how well any method works.
Augmentative and alternative communication: the ways people communicate when speech is difficult or not available, from gestures and signing to picture boards and speech-generating devices.
The Picture Exchange Communication System, a low-tech system in which a person communicates by exchanging or pointing to pictures.
This is the usual description used by speech experts. It says what AAC covers, not how well it works.
Short for augmentative and alternative communication. Ways to communicate when talking is hard.
A low-tech system where a person communicates by giving or pointing to pictures.
Does AAC hold back speech? Established
A common worry is that giving a child a communication device will keep them from learning to talk. The evidence does not support that. In a 2006 meta-analysis of 23 studies and 67 people with developmental disabilities, mostly intellectual disability or autism, using sign or low-tech AAC, none of the 27 cases in studies that established experimental control lost speech, and 89% of those cases gained some, though the gains were modest.4 A 2008 systematic review of autistic children concluded that AAC does not impede speech, and most studies reported an increase, again modest.5 A review published in 2021 that updated the 2008 one found speech improved with AAC but did not catch up with the person's own use of AAC.6
Two randomized trials point the same way. In one, 68 toddlers with developmental delays who had fewer than ten spoken words were assigned by chance to a parent-coached spoken-language program or to one of two augmented-communication programs; the children in the augmented groups used more words, and the authors concluded that augmented communication does not hinder speech and in fact aids it.7 In the other, 61 minimally verbal autistic children aged 5 to 8 were assigned by chance to a blended behavioral program with or without a speech-generating device; spontaneous utterances, new words and comments all favored the group that began with the device.8
Because the gains are usually modest, the reviews say AAC should be valued as a way to communicate now, rather than only as a step toward speech.5
Some parents worry that a communication device will stop a child from learning to talk. The studies do not show that. One big review found that nobody lost speech. Most people gained some, but only a little.4 A review of autistic children found the same thing.5 A later review found speech went up, but not as high as the person's AAC use.6
Two studies split children into groups by chance. In one, toddlers with few words used more words when they got AAC.7 In the other, autistic children aged 5 to 8 used a talking device. They said more words and made more comments than the group without it.8
The gains are small. So AAC is a way to communicate now, not only a step toward speech.5
Randomized trials and reviews agree: AAC does not reduce speech, and where people gain speech the gains are modest. The earliest review rests mostly on uncontrolled studies of sign and low-tech systems.
Reviews and two fair-comparison studies agree. AAC does not stop speech. When speech improves, it improves a little.
What the reviews have studied Established
The largest review of AAC in autism, published in 2026, gathered 69 papers.2 Across them were 421 autistic participants, from age 1 year 8 months to 44 years, but the great majority were children, and the most common age group was 5 to 8 years. More than half of the studies had mostly male samples, and 33 included boys only.2
Only three of the 69 papers looked at how AAC works for adults, and between them they covered five adults, aged 23 to 44. None looked at anyone aged 65 or over.2
What the studies measured was mostly the next step in front of them: whether a person could make a simple request. Few looked at whether new communication carried over to other settings, or at wider outcomes such as quality of life. The authors rated the study quality generally low, with a mean of 2 out of 5 on their appraisal scale.2 A separate mega-review of 84 reviews of AAC for children with intellectual and developmental disability found the reviews themselves often had methodological weaknesses that weakened the strength of the evidence.9
Two more reviews, both published in 2026, reached similar conclusions. One of 14 studies of play-based AAC for children aged 3 to 8 found the studies hard to compare and the definitions of play broad.3 One of 18 studies of communication support for minimally verbal children found the results mixed, with the most consistent improvements in spontaneous communication.10
The biggest review of AAC in autism came out in 2026. It gathered 69 studies.2 Together they had 421 autistic people, from age 1 to 44. Most were children. The most common age was 5 to 8. Most studies had mostly boys.2
Only 3 of the 69 studies looked at adults. They had 5 adults, aged 23 to 44. No study looked at anyone over 65.2
Most studies asked one small question: can the person ask for something? Few looked at other things, like whether new skills lasted or helped quality of life. The authors said the studies were mostly low quality.2 Another big review found the same problem.9
Two more reviews came out in 2026. One found 14 studies of play-based AAC that were hard to compare.3 One found 18 studies with mixed results.10
These are findings about the state of the research itself, from the systematic reviews that gathered the past decade of AAC studies. They describe what has been studied, not how well AAC works.
These facts are about the research itself. They say what scientists studied, not how well AAC works.
Communication beyond requests Emerging
Requesting is the function AAC is most often taught for.2 Other uses of communication get much less attention. In one study, researchers logged the words produced on the devices of 11 children aged 8 to 10 over 126 days and found only eight emotion words, used rarely.11 Newer work has tried play-based and naturalistic teaching to reach more of communication. In a single-case study of three students aged 4 to 8, coaching their educators in play-based AAC produced descriptive gains in the students' communication, but the gains did not carry over to peer interactions.12 Which words go on a device, and how their use is taught beyond requests, remains thinly studied.
Asking for things is what AAC is mostly taught for.2 Other uses get less study. One study watched 11 children's devices for 126 days. It found only 8 feeling words, and they were used rarely.11 Some newer studies use play to teach more. One small study with 3 children found a little improvement. But it did not carry over to play with other children.12
The reviews describe the field's focus as requesting. The studies of other communication functions are single and small.
Most AAC research teaches asking for things. Studies of other uses are few and small.
Who is nonspeaking, and who stays that way Emerging
How many children stay nonspeaking is a live question. In one large dataset of 707 autistic preschoolers who received early intervention that targeted speech, 293 were non-speaking at the start.13 By the end, about two-thirds of those children were using single words or more, so about a third of the children with little or no speech did not reach spoken language. Of the children who were minimally speaking at the start, about half were combining words by the end.13 Which intervention the child received did not change the odds of gaining speech in this dataset; the authors point instead to factors that can be changed, such as how long the intervention lasts and the child's age when it starts. The lower motor-imitation scores reported below came mainly from parents' reports.13
A separate review of 20 samples found that, on average, about 48% of children moved from single words to phrases, with wide variation between the studies.14
Some children stay nonspeaking, and some learn to talk later. In one large study, 707 autistic preschoolers got early help with speech. At the start, 293 did not speak.13 By the end, about two-thirds of those children used single words or more. About one-third still did not speak. Which program a child got did not change the result.13
Another review looked at 20 groups of children. On average, about 48% moved from single words to phrases. But the studies differed a lot.14
These come from a few large but separate datasets. None has been repeated by another team.
These come from a few large studies. No other team has repeated them.
Motor barriers to speech Emerging
Speech can fail for reasons that are not about language. In a study of 193 minimally verbal school-age children (77% autistic, 15% with a genetic syndrome, and some measures adapted rather than standardized), the researchers grouped them into six clusters.15 Two of the clusters showed a clear gap: the children understood much more than they could say. The authors read this as a sign that motor barriers, rather than understanding, may hold speech back for some children, and they say these children need support tailored to that.15
The same pattern appears elsewhere. Children who stayed non-speaking after early intervention had lower motor imitation scores at the start.13 A small account written with three minimally speaking autistic people describes apraxia as a body-wide motor difficulty and argues it should be separated from how much a person understands.16
Motor differences are one account among several, and they have not yet been tested as a mechanism.
Not speaking is not always about words. One study of 193 children sorted them into six groups.15 Two groups understood much more than they could say. The authors think movement may block speech for these children.15 Other children who stayed nonspeaking also moved less well at the start.13 One small account comes from three minimally speaking autistic people. They say apraxia is a body-wide movement problem. They say it is separate from understanding.16
One large cohort, one dataset on motor imitation, and one account by minimally speaking people themselves. The motor account is offered as an explanation, not yet a tested mechanism.
A difficulty in planning and carrying out movements that a person intends to make, including the movements of speech.
One big study, one set of parent scores, and one account by minimally speaking people. The idea is a possible reason, not a proven cause.
Trouble planning and making movements on purpose, including the movements of speech.
Adults: the gap and the measures Emerging
Almost all AAC research stops at childhood. A 2017 systematic review of AAC for autistic adolescents and adults concluded that AAC benefits them, but it called for much more research and for work on communication functions beyond requesting.20 The 2026 review, which took in papers published after 2013, found only three of its 69 papers covered adults, five people in total, and it too calls for a stronger focus on adults.2 The gap runs back decades.
What exists for adults is also mostly about measuring how a person is doing. Two teams tested caregiver-report tools with non- or minimally speaking autistic adults. In one study of 160 caregivers, a depression screen (the Glasgow Depression Scale caregiver supplement) and the ADAMS, which also captures anxiety, showed acceptable to strong measurement properties, though the cut-off scores were exploratory; a third measure, the MIPQ, fitted poorly.17 The other study, of 94 caregivers of young adults with an average age of about 21, found that a short daily-living measure, the W-ADL, matched a longer established scale, though it covers community skills poorly.18 Both rest on caregivers' reports rather than the adults' own answers, a limit for people who communicate without speech.17,18
A review of communication in autistic adults reports that many meet barriers in relationships, employment and health care, coming from language, nonverbal communication, and environments and communication partners that do not accommodate them.19
Almost all AAC research is about children. One review from 2017 found AAC helps autistic teens and adults, but there are few studies.20 The 2026 review found only 3 of 69 studies about adults, and it asks for more.2
For adults, most research is about measuring how someone is doing. One study asked 160 caregivers about depression. Two tools worked fairly well. A third did not.17 Another study asked 94 caregivers about daily living skills. A short tool matched a longer one.18 Both rely on what caregivers say, not what the adults say themselves. That is a problem for people who do not speak.17,18
A review says many autistic adults meet barriers in relationships, jobs and health care.19
A gap count from two systematic reviews and two measures tested with caregivers. The adult studies do not follow people over time.
Two reviews and two tools that caregivers filled in. The adult studies do not follow people over time.
Access and training Emerging
Whether AAC is available and used well depends on the people around the user. A survey of 30 board-certified behavior analysts found they knew the low-tech picture system PECS but were less sure of high-tech AAC, and most wanted more training.21 A survey of 567 school-based professionals found their definitions of autistic speech centered on speech itself and sometimes ruled out other forms of communication.22
Parents also report barriers. In a study of 75 parents in Nablus, Palestine, almost all saw a benefit from AAC, most often more chances to communicate, and many described difficulty getting and using it.23 A scoping review of 18 articles on autistic people in distress found that, in many of the studies, distress was communicated without speech, through gestures, facial expression or behavior, and that a calm setting and communication aids helped.24
Good AAC use depends on the people nearby. In one survey, 30 behavior analysts knew the picture system PECS but were less sure about high-tech AAC. Most wanted more training.21 Another survey of 567 school workers found their idea of speech left out other ways to communicate.22
Parents also meet barriers. In a study of 75 parents in Nablus, Palestine, almost all saw AAC help their child. Many found it hard to get and use.23 One review of 18 studies found that people often show distress without speech. A calm place and communication aids help.24
Surveys of professionals and parents, each from one sample or one country. They describe access and training, not outcomes.
Surveys of workers and parents. Each comes from one group. They describe who can get AAC, not what it does.
In the community Community
Autistic writers place AAC inside a wider argument about communication and access. Paula C. Durbin-Westby, an autistic self-advocate, writes that research should center communication needs, that "a communication device is not communication," and that "AAC can benefit Autistics who do have speaking capability as well as those who do not use speech to communicate."c1 Devon Price, an autistic social psychologist, writes that nonspeaking autistic people "are fully formed people who are typically capable of communicating with the help of assistive devices, letter boards, sign language, texting, or through their behavior," and that forcing speech does not work.c2
Some writers frame access to communication as a right. In I Will Die On This Hill, autistic writers argue that "accessible communication is a human right" and that AAC should be offered first to autistic students who are nonspeaking or have delayed speech, rather than a behavior program.c3
Autistic writers see AAC as part of a bigger idea. Paula C. Durbin-Westby is an autistic writer. She writes that "a communication device is not communication."c1 AAC helps people who speak and people who do not.c1 Devon Price is also an autistic writer. He writes that most nonspeaking autistic people can communicate. They use devices, boards, sign language, or texts. Forcing speech does not work.c2
Some writers call communication a right. In the book I Will Die On This Hill, autistic writers argue for communication access. They call accessible communication "a human right," so they want AAC offered first to students who do not speak.c3
How autistic writers describe AAC. Not a research finding.
How autistic writers talk about AAC. This is not a research finding.
From nonspeaking writers Nonspeaking
Nonspeaking autistic people who use AAC describe what it opens up. Grant Blasko, who points on an iPad with a word-prediction app, writes: "I rely solely on Augmentative and Alternative Communication (AAC)."c4 He attends a large public high school as its only AAC user, and has been accepted into a university scholars program.c4 Jordyn Zimmerman, who began using an iPad at 18, writes: "I had a communication breakthrough when I began to use an iPad," touching pictures and letters to make complete sentences.c5
Nonspeaking autistic people who use AAC say what it opens up. Grant Blasko points on an iPad with a word-prediction app. He relies on AAC all the time.c4 He is the only AAC user at his school, and he was accepted into a program for young scholars.c4 Jordyn Zimmerman began using an iPad at 18. She writes about "a communication breakthrough." She touched pictures and letters to make sentences.c5
In their own words, written by typing, spelling, handwriting or AAC, some with a communication partner's support. Researchers dispute whether some partner-supported methods let the writer, not the partner, choose the words; the pedia reports these accounts as their writers' and does not settle that question here. The methods and the evidence about who authors the words are set out in Facilitated communication and spelling to communicate.
In their own words, written by typing, spelling, handwriting or AAC. Some used a partner's help. Researchers argue about whether some partner-supported methods let the writer choose the words. The pedia reports these accounts as their writers' and does not settle that question here. You can read about these methods in Facilitated communication and spelling to communicate.
Sources
Research
- 1American Speech-Language-Hearing Association. Augmentative and Alternative Communication (AAC). ASHA, 2026. https://www.asha.org/public/speech/disorders/aac/
- 2Mifsud S, Thomas D, Bowron R, Sutherland R. The Predominant Focus Is Still on Teaching Children to Make Requests: A Systematic Review of AAC for Autistic Adults and Children. International Journal of Language & Communication Disorders, 2026. https://doi.org/10.1111/1460-6984.70251
- 3Klein MJ, Banerjee A, Bhana-Lopez N, Ganz JB, Bodenhamer S, Altamira W. A Systematic Review of Play-Integrated AAC Interventions for Minimally Verbal and Nonspeaking Children. Autism & Developmental Language Impairments, 2026. https://doi.org/10.1177/23969415261441185
- 4Millar DC, Light JC, Schlosser RW. The impact of augmentative and alternative communication intervention on the speech production of individuals with developmental disabilities: a research review. Journal of Speech, Language, and Hearing Research, 2006. https://pubmed.ncbi.nlm.nih.gov/16671842/
- 5Schlosser RW, Wendt O. Effects of augmentative and alternative communication intervention on speech production in children with autism: a systematic review. American Journal of Speech-Language Pathology, 2008. https://pubmed.ncbi.nlm.nih.gov/18663107/
- 6White EN, Ayres KM, Snyder SK, Cagliani RR, Ledford JR. Augmentative and Alternative Communication and Speech Production for Individuals with ASD: A Systematic Review. Journal of Autism and Developmental Disorders, 2021. https://doi.org/10.1007/s10803-021-04868-2
- 7Romski M, Sevcik RA, Adamson LB, Cheslock M, Smith A, Barker RM, Bakeman R. Randomized comparison of augmented and nonaugmented language interventions for toddlers with developmental delays and their parents. Journal of Speech, Language, and Hearing Research, 2010. https://pubmed.ncbi.nlm.nih.gov/20360461/
- 8Kasari C, Kaiser A, Goods K, Nietfeld J, Mathy P, Landa R, Murphy S, Almirall D. Communication interventions for minimally verbal children with autism: a sequential multiple assignment randomized trial. Journal of the American Academy of Child & Adolescent Psychiatry, 2014. https://doi.org/10.1016/j.jaac.2014.01.019
- 9Crowe B, Machalicek W, Wei Q, Drew C, Ganz J. Augmentative and Alternative Communication for Children with Intellectual and Developmental Disability: A Mega-Review of the Literature. Journal of Developmental and Physical Disabilities, 2022. https://doi.org/10.1007/s10882-021-09790-0
- 10Privitera R, Piccolo A, De Domenico C, Leonardi G, Alito A, Quartarone A, Cucinotta F, Di Cara M. Interventions to Promote Communication in Minimally Verbal Autistic Children: A Systematic Review. Medical Sciences, 2026. https://doi.org/10.3390/medsci14030388
- 11Bean A, Kovacs P, Sonntag AM. Emotion word production on the devices of nonspeaking school-aged autistic children who use augmentative and alternative communication. International Journal of Speech-Language Pathology, 2026. https://doi.org/10.1080/17549507.2026.2667825
- 12Biggs E, Turner E, Lee S. Play-Based Naturalistic Augmentative and Alternative Communication (AAC) Intervention: Educator Fidelity and Effects on Communication and Peer Interactions. Behavioral Sciences, 2026. https://doi.org/10.3390/bs16081275
- 13Vivanti G, Lombardo MV, Zitter A, Boyd B, Dissanayake C, Dufek S, Flanagan HE, Iadarola S, Kaiser A, Kim SH, et al. Proportion and Profile of Autistic Children Not Acquiring Spoken Language Despite Receiving Evidence-Based Early Interventions. Journal of Clinical Child & Adolescent Psychology, 2025. https://doi.org/10.1080/15374416.2025.2579286
- 14Byrne K, Sterrett K, Lord C. Examining the Transition from Single Words to Phrase Speech in Children with ASD: A Systematic Review. Clinical Child and Family Psychology Review, 2024. https://doi.org/10.1007/s10567-024-00507-1
- 15Saul J, Cooke M, Munaweera S, Matthews D. Sub-groups of spoken language and broader communication skills in a large heterogenous cohort of minimally verbal school-age children: evidence of discrepant profiles. Molecular Autism, 2026. https://doi.org/10.1186/s13229-026-00701-8
- 16Damiao J, Damiao G, Polanco J, Lockwood M, Quinn J. Ethnographic Perspectives of Unreliable, Minimal and Non-Speaking Autism Associated With Apraxia. OTJR: Occupation, Participation and Health, 2026. https://doi.org/10.1177/15394492251397894
- 17Wilkinson E, Pai K, Jahoda A, Hastings RP, Bal VH. Depression Screening Tools for Non- and Minimally Speaking Autistic Adults: Feasibility, Psychometrics, and Wider Validity. Autism, 2026. https://doi.org/10.1177/13623613261480395
- 18Wilkinson E, Yu YY, Bal VH, Clarke EB. Examining the Utility of the W-ADL to Assess Daily Living Skills in Non- or Minimally Speaking Autistic Adults. Journal of Autism and Developmental Disorders, 2026. https://doi.org/10.1007/s10803-026-07309-0
- 19de Marchena A, Cuneo N, Gurbuz E, Brown M, Trujillo J, Bergstrom J. Communication in Autistic Adults: An Action-Focused Review. Current Psychiatry Reports, 2025. https://doi.org/10.1007/s11920-025-01616-6
- 20Holyfield C, Drager KDR, Kremkow JMD, Light J. Systematic review of AAC intervention research for adolescents and adults with autism spectrum disorder. Augmentative and Alternative Communication, 2017. https://doi.org/10.1080/07434618.2017.1370495
- 21Roylance A, D'Agostino SR, Briggs A, Bhana-Lopez N. Exploring Knowledge and Sources of Information on Augmentative and Alternative Communication Among Board-Certified Behavior Analysts. Behavioral Sciences, 2026. https://doi.org/10.3390/bs16081402
- 22Zisk AH, Eddy B, Donaldson AL, Cannalonga S, Strickland O, Corbin E, Schall JHT. School-Based Professionals' Knowledge of Autistic Speech and Augmentative and Alternative Communication Decision Making. Seminars in Speech and Language, 2024. https://doi.org/10.1055/s-0044-1793928
- 23Jarrar H, Malhis L, Munawer A, Omareya M, Deek N, Abutair R, Dodeen S, Khadeje SM, Abu-Shamat Z. Parent-reported benefits, barriers, and experiences of augmentative and alternative communication use among children with autism in Nablus, Palestine: a cross-sectional study. BMC Pediatrics, 2026. https://doi.org/10.1186/s12887-026-07161-2
- 24Oldenburg K, Gibbons T, Welch C, Tint A, Albin M. Describing the communication of autistic people during experiences of distress: A scoping review. Autism, 2026. https://doi.org/10.1177/13623613261417933
Community sources
- c1Bascom J, ed. Loud Hands: Autistic People, Speaking. The Autistic Press, 2012. Section "Moving Forward", contribution by Paula C. Durbin-Westby. Julia Bascom's site
- c2Price D. Unmasking for Life: The Autistic Person's Guide to Connecting, Loving, and Living Authentically. Harmony Books, 2025. Chapter "Parenting for Neurodiversity". Devon Price's site
- c3Ashburn M, Edwards J, Onaiwu M. I Will Die On This Hill: Autistic Adults, Autism Parents, and the Children Who Deserve a Better World. Jessica Kingsley Publishers, 2023. Chapter "School Inclusion and Safety".
- c4Peña E, ed. Leaders Around Me: Autobiographies of Autistics who Type, Point, and Spell to Communicate. Self-published, 2019. Chapter "35 Grant Blasko".
- c5Peña E, ed. Leaders Around Me: Autobiographies of Autistics who Type, Point, and Spell to Communicate. Self-published, 2019. Chapter "33 Jordyn Zimmerman".