What is stammering

Dysfluency, Stammering and Down's Syndrome

Leaflet cover: Dysfluency, Stammering and Downs's SyndromeThis text is designed to help people who have Down's syndrome and who care for and work with people who have Down's syndrome to understand the problem of dysfluency in speech. People with Down's syndrome are born with an extra chromosome as a result of a genetic accident before or around the time of conception. This results in a certain degree of learning difficulty which can affect the ability to understand and produce speech and language. One of the biggest problems for many people with Down's syndrome is the unintelligibility of their speech to others. Unintelligibility and dysfluency gohand in hand. Many people with Down's syndrome are dysfluent and a few of these people also stammer, or stutter. That is why it is important to understand the difference between the two terms - dysfluency and stammering.

What is dysfluency and what is stammering?

Not one of us is perfectly fluent. We all hesitate and stumble over words; we pause to think; we go back over what we've already said; we start a word and then change it into another word; we 'um' and we 'er'. This lack of fluency is normal for both adults and children, though in children it tends to occur more frequently.

If these hesitancies and stumblings make speech difficult to understand, or if they occur too often or with too much effort, they may be seen a abnormal. In this case we may use the term 'dysfluency'.

Stammering (or stuttering) is the most common form of dysfluency and is the word most familiar to people. This word is correctly used when one or more of the following occur:

The speaker

  • feels unable to move ahead in speech, he or she feels stuck, or repeats sounds, or prolongs sounds
  • feels tense and may use a lot of effort to get words out
  • feels upset or distressed by the difficulty of speaking
  • knows exactly what word is to be said but cannot say it
  • often finds ways to avoid speaking or saying the words that are difficult

The word 'dysfluency' may cover many of the same things but also includes:

  • difficulty in pronouncing words accurately
  • missing out parts of words or sentences
  • repeating whole sentences or parts of sentences
  • putting in extra unwanted speech sounds
  • putting the emphasis on the wrong words in sentences or the wrong part of the word

The speech of people who are dysfluent may be hard to understand, it may seem to be jerky or disjointed, and it does not flow easily from one word to the next.

The Effect of Down's Syndrome on Language and Fluency

It has been suggested by some experts that the process of producing language goes something like this:

The effect of Down's Syndrome Language the Fluency. It has been suggested by some experts that the process of producing language goes something like this: 1. The idea is formed. 2. The idea is converted into a language programme. 3. The language programme is converted into a speech muscle movement programme. 4. The idea is spoken. 5. The message is heard. 6. The message is understood. At any time we may notice and correct mistakes - this is called FEEDBACK.

People with Down's syndrome may find some or all of these steps particularly difficult. Ideas may not be clearly formed; the language plan and/or speech may be a problem. As well as this, hearing loss, which is quite common in people with Down's syndrome, makes learning and understanding language difficult. Also, the individual may lack the social awareness needed to know when or where it is appropriate to say what is wanted.

For all of us it is common to find that, as the pressure to speak and speak well builds, a breakdown in fluency may occur. Imagine that you are trying to plan what to say in a foreign language - one where you only know a few words! You are likely to have long pauses when you are thinking of words; you might start a word, realise it's wrong and try another word; you may repeat a word a number of times while you are trying to plan the sentence. In fact you may appear very dysfluent!

For a person with Down's syndrome, wanting to convey messages through a system that does not always work perfectly, may lead to:

  • Repeating whole words or parts of words while trying to think of the next bit of the sentence (it's...it's...it's...it's big).
  • Long pauses in the middle of the sentence when he or she can't think of what to say next (it's a........ball).
  • Pauses in unusual places in sentences, often followed by two or three words in a sudden rush that may be hard to understand (I'm going swim......mint'morrow). This stop-and-start speech can be caused by problems in the language programme or in the conversion of the language into a speech muscle programme. The effect is as if the 'bottled up' air is escaping from the lungs in a rather uncontrolled fashion. Fluent speech is dependent on a steady flow of air.
  • Emphasis being placed on the wrong word in a sentence or on the wrong part of the word. This may occur because the language programme is not precisely planned or the control of movements of the speech muscles is not sufficiently well organised (I like to eat apples)
  • Some struggling to find the right speech sound to start the word off (a...er...er.i...er...um...over there). Sometimes it may be difficult for the person to start the voice working leading to sudden high pitched or loud sounds.
  • Possible problems with hearing others and/or with noticing that what has been heard has not been understood. This may lead to hesitant and unsure speech and to communication between the person with Down's syndrome and the listener breaking down.

Demands and Capacities

One of the experts in the field of dysfluency put forward the idea that fluency depends on an equal balance between demands made on the language system and the abilities (or capacities) of the individual which helps him or her to meet these demands. Dysfluency occurs when demand exceeds capacities.

These are just a few of the demands made upon speakers and the capacities that a speaker needs to have in order to manage well. There are many others that can be added.

How can people with Down's syndrome be helped?

Following on from the previous model, we can see how our aim is to try and balance the scales by decreasing demands and increasing capacities.

Decreasing demands:

  • Give the person with Down's syndrome plenty of time. Planning what to say and saying it may be slower than you might expect.
  • Take a slightly longer pause between what he or she has said and your reply - this slows the overall speed of the conversation down. Encourage the adult or child also to take longer pauses. This allows thinking time before speaking.
  • Try to avoid finishing sentences or saying what you think he or she might be trying to get across.
  • Speak a little slower yourself - this gives a model for the child or adult with Down's syndrome to follow.
  • Try not to use too many long and complicated sentences.
  • Give positive encouragement for the message rather than the style of delivery.

Increasing capacities:

  • For children, helping the language to develop and the vocabulary to expand may reduce the amount of dysfluency. Rhymes and jingles that have a strong rhythm and can be moved to or clapped out are particularly useful. However, it is important not to make too many demands for speech - this can have a negative effect.
  • Encouraging the use of sign language and other aids (such as pointing to pictures etc) reduces the pressure on children or adults who are dysfluent and difficult to understand
  • Encouraging the development of good social and communication skills (such as knowing when to speak and when not to speak, looking at people when talking to them, listening carefully, smiling and nodding, taking it in turns to speak) helps build confidence. Speaking is only a small part of communicating.

Most children with Down's syndrome will be particularly dysfluent while their language is developing and their vocabulary is expanding. The dysfluencies may pass or reduce as they become better at planning and organising their language. However, for some, language and speech may always be difficult.

As adults, a number of people with Down's syndrome will be quite difficult to understand at times and they may have bouts of dysfluency varying from mild hesitancies to more severe struggling to get words out. The most important thing is that they should feel that what they say has value and that others want to listen to them. Attempts to make people imitate sentences or practise speaking in different ways are unlikely to produce more fluent, clearer speech in the long run, and this might make them feel that the payoffs for speaking are not worth the effort.


Do talk about the problems of dysfluency amongst yourselves and with people who can help. Don't feel you can't or mustn't say anything. By avoiding talking about the issues you could be making yourself and the person who has the problem feel worse about it.

Talk to:

A speech and language therapist - particularly one who has knowledge of Down's syndrome, and

The Down's Syndrome Association
Langdon Down Centre
2a Langdon Park
TW11 9PS
Website: www.downs-syndrome.org.uk

Text: Monica Bray, Senior Lecturer in Speech Pathology,
Leeds Metropolitan University, Leeds LS1 3HE