Communication and Down Syndrome: The Profile, and What Actually Helps

Communication and Down syndrome: the profile, and what actually helps

There is a pattern that almost every family of a child with Down syndrome recognises and almost nobody has had explained to them.

The child clearly understands far more than they can say. You can see it. You ask her to get her shoes and she gets her shoes. You mention the park and she goes to the door. But asking her to tell you about her day produces two words, and a stranger would not understand either of them.

That gap is not a coincidence or a motivation problem. It is the central structural feature of language in Down syndrome, it has been measured repeatedly, and it has specific implications for what you should do about it. This guide sets out what the research says, and what follows from it in practice.

It is written for parents making early decisions, for support workers trying to communicate better with an adult, and for anybody who has been told to “just keep talking to her, it’ll come.”

The profile

Four findings, each from a reasonably solid research base, and the Down Syndrome Education research library is a good entry point to the primary literature.

1. Expressive language is harder than receptive

Expressive and receptive language diverge as children with Down syndrome develop. Understanding tends to track closer to overall cognitive level; production falls further behind.

Abbeduto and colleagues found impairments in receptive language, expressive language and theory of mind that were substantially larger than the nonverbal cognitive deficit — and importantly, that this pattern was not seen in children with fragile X syndrome. So this is not just “intellectual disability affects language.” It is a profile specific to Down syndrome.

2. Grammar is weaker than vocabulary

Lexical and syntactic knowledge diverge over development. Vocabulary keeps growing; grammar — and particularly expressive syntax — lags well behind.

Chapman and Hesketh identify expressive syntax and auditory short-term memory as the two areas of particular difficulty. That is a strikingly specific pair of findings, and the second explains a lot of the first.

3. Verbal short-term memory is specifically impaired

This is the finding that changes practice, and it is the one almost nobody is told.

Jarrold and Baddeley concluded that Down syndrome is associated with a specific memory problem, localised to the phonological loop — the part of working memory that holds speech sounds briefly while you process them. Verbal short-term memory is typically weaker than visual and spatial short-term memory in Down syndrome, and the gap is larger than general cognitive ability would predict.

Two important details. First, hearing and speech problems do not appear to be the main cause — this is a memory deficit in its own right, not a downstream consequence of glue ear, though glue ear makes everything worse. Second, Vicari found that implicit memory in children with Down syndrome was comparable to typically developing peers while explicit memory was weaker.

4. Visual learning is relatively strong

The corollary of the above: what comes in through the eyes and stays is more reliable than what comes in through the ears and has to be held.

Put all four together and you get the explanation for the pattern the parents noticed.

A sentence spoken aloud has to be held in the phonological loop long enough to be parsed. If that buffer is short, long sentences degrade before they are understood, and — on the production side — a child cannot build and hold a grammatically complex utterance long enough to say it. Vocabulary, which is stored long-term rather than held briefly, is less affected. Understanding in context, supported by gesture and situation and routine, is less affected still.

So: she understands “get your shoes” because it is short, familiar, situationally supported and she does not have to hold it. She cannot tell you about her day because that requires assembling and maintaining several clauses with no external support at all.

What follows from this

Here is where the research becomes useful rather than merely interesting.

Use the visual channel deliberately

If visual memory is the relative strength and verbal short-term memory is the specific weakness, then anything important should be visible, not just said. This is not a concession to disability. It is playing to the actual cognitive profile.

Concretely: visual timetables rather than verbal explanations of the day. Written or pictorial instructions for multi-step tasks. Photographs of what the finished task looks like. A written word alongside the spoken one. Choice boards rather than open verbal questions.

And the single highest-value habit for anybody supporting a person with Down syndrome: write it down and hand it over. An appointment time said aloud is gone. An appointment time written on a card stays.

Sign early, and do not wait for speech

Key Word Sign — the Australian system, drawn from Auslan signs used alongside speech rather than instead of it — is the standard early recommendation for children with Down syndrome, and the rationale follows directly from the profile. Signs are visual and manual. They do not require the phonological loop. They do not require the fine oral-motor control that hypotonia makes difficult. And a child who can sign can communicate at their comprehension level rather than their production level, which is a much higher level.

The persistent worry — that signing will delay speech — is not supported. The consistent finding is the reverse: signing supports the development of spoken language, and most children who sign early and go on to develop speech drop the signs themselves as speech becomes more efficient.

The practical failure mode is adoption. Signing only works if the people around the child sign. A child who signs at therapy and nowhere else has a therapy activity, not a communication system. If you are a family starting this, the goal is for grandparents, siblings, the school aide and every support worker to have at least thirty signs.

Reading can be a route into talking, not a reward for it

This one is counterintuitive and it has a reasonable evidence base behind it.

The conventional sequence is speech first, then reading. The Down syndrome literature has long argued the opposite can work: that because written words are visual and permanent — they do not decay in the phonological loop — reading can be taught earlier than expected and used deliberately to support spoken language and grammar.

A written word sits still. A child can look at it for as long as they need. Two-word and three-word phrases presented in print can be practised in a way that spoken models cannot, because the model does not disappear.

Many children with Down syndrome can begin learning sight words from two or three years old, well before speech is established, and reading is often a relative strength in adulthood. If your child’s school has told you reading will come when speech comes, that is the wrong order on the evidence.

Shorten and support, don’t simplify and slow

A distinction worth being precise about, because adults with Down syndrome find the usual approach patronising and it also does not work.

Helpful: shorter sentences. One instruction at a time. A pause after speaking — a real one, five to ten seconds, which feels unbearably long and is usually about right. Gesture alongside speech. Showing as well as telling. Writing the key word down. Checking understanding by asking the person to do or show rather than asking “do you understand?”

Not helpful: talking louder. Talking very slowly in a singsong voice. Baby talk. Using a smaller vocabulary than the person understands. Asking yes/no questions when you want information, because yes is the path of least resistance for everybody. Finishing their sentences.

The pause is the one to work on. Processing takes longer, retrieval takes longer, and articulation takes longer. Most conversations with people with Down syndrome are closed down by the other person filling the gap at three seconds. Count to eight.

AAC is not a last resort

Augmentative and alternative communication — anything from a paper communication board to a speech-generating app on an iPad — is still too often presented as what you turn to when speech has failed.

For Down syndrome specifically, the argument for AAC is positive rather than remedial: it externalises the utterance. A person selecting symbols or words on a board is not holding a sentence in a weak phonological buffer. The sentence is in front of them. That is working with the profile, not around a failure.

AAC also does not stop speech developing, and this question has been asked and answered often enough in the broader literature that it should not still be a barrier. In practice, people use whatever is fastest, which for many people with Down syndrome is speech for familiar things and AAC for anything complex, unfamiliar or important.

Where AAC falls down in Australia is almost never the device. It is the implementation: a device provided and never programmed with the person’s actual vocabulary, support workers who do not know how to use it, a device that lives in a cupboard because it might get broken, no one modelling its use. Our guide to communication and AAC in the cerebral palsy series covers the device and funding mechanics in more detail, and much of it carries across.

Speech intelligibility, and the things that make it worse

Speech in Down syndrome is often less intelligible than the person’s language level would predict, and there are several contributors, most of them addressable.

Hypotonia and oral-motor control. Reduced tone affects the tongue, lips, jaw and palate, and therefore precision.

Structural factors. A relatively large tongue in a smaller oral cavity, a high narrow palate, dental crowding and malocclusion.

Hearing. This is the big addressable one. Glue ear is close to universal in early childhood, the ear canals are narrow and hard to examine, and hearing loss in Down syndrome is often progressive into adulthood. A child who cannot clearly hear the difference between two speech sounds will not produce the difference reliably. Annual audiology is a speech intervention, and this is the most commonly dropped item in Australian practice.

Apraxia of speech, which is more common in Down syndrome and which needs a different treatment approach from a straightforward articulation disorder — motor planning practice rather than sound drilling.

Sleep apnoea. Chronic nasal obstruction and mouth breathing affect articulation, and the fatigue affects everything. See sleep apnoea and Down syndrome.

The practical point: before intensifying speech therapy for an unintelligible child or adult, check the hearing and check for sleep-disordered breathing. Therapy delivered over an uncorrected conductive hearing loss is a waste of everybody’s money.

Language development does not stop at 18

Chapman and Hesketh report that language skills in Down syndrome continue to develop into adolescence, and clinical experience suggests development continues well beyond that where there is input.

This matters because of what happens to therapy funding in Australia. Speech pathology for children with Down syndrome is usually well resourced. Speech pathology for adults with Down syndrome is frequently zero, on an unstated assumption that language development is finished and the rest is maintenance.

It isn’t, and the adult work is different and valuable: vocabulary for the person’s actual adult life, self-advocacy language, how to say no, how to tell someone you are in pain, how to use the phone, how to communicate with a doctor, how to tell a worker you do not want to do something. Those are learnable and they are the skills that protect people.

Funding it properly under the 2026–27 price limits

Speech pathology sits at $193.99 per hour in 2026–27. The items that get forgotten are the ones that make the difference:

A plan with ten hours of speech pathology and no non-face-to-face allowance will produce an assessment, a report, and almost no change. The implementation work — building the device vocabulary, writing the one-page communication profile, training eight support workers to use it consistently — is where communication outcomes actually come from, and it is nearly all _NF.

The one-page communication profile

If you do one thing after reading this, make this document. It takes an hour and it travels with the person for the rest of their life.

One page, in plain language, covering:

How I communicate — speech, signs, device, gestures, and which I use when.

How to talk to me — short sentences, one thing at a time, wait at least eight seconds, write key words down, show me rather than telling me.

Words I use that you might not understand — the personal vocabulary every family has and every new support worker has to learn by trial and error. Write it down. “Bobba” means his brother Rob. “Going out out” means the pub, not the shops.

How you’ll know I’ve understood — and how you’ll know I haven’t, which is usually the more useful half. Many people with Down syndrome will say yes to be agreeable; the profile should say so.

How you’ll know I’m in pain, upset or frightened — behaviours, not words. This is the section that prevents the most harm.

What I want to be asked about — and what I do not want decided for me.

Who knows me best, and their phone number.

Put it in the front of the support plan, send it to the hospital with the person, give it to every new worker on their first shift, and update it annually. For a person with limited speech who ends up in an emergency department with a staff member who has never met them, this piece of paper is the difference between being understood and not.