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Department of Linguistics


Adam Smith, with expert input from Dr Elisabeth Harrison of Macquarie University, summarises information on the nature of stuttering and new research into the condition.


Aside from the recently well-publicised case of King George VI, many notable figures throughout history have suffered from stuttering. The Greek orator Demosthenes is said to have corrected his speech impediment by putting pebbles in his mouth, and the Roman emperor Claudius's debilitating stutter was recorded by the historian Suetonius. Other famous stutterers include Isaac Newton, Henry James and Lewis Carroll - who was unable to become a priest partly because he stuttered. In recent times, the actor Hugh Grant has used a stutter to enhance the nervous charm of his screen persona.

For those who suffer from stuttering, it can be the cause of ongoing social and psychological distress, especially if the condition persists. It is most common for children - about 1 in 10 children stutter at some point in childhood, but for most the problem is resolved spontaneously. Still, in Australia, approximately one per cent of the population, or around 200,000 people stutter.

Causes of stuttering

For such a common disorder, it is surprising how little is still known about its causes. There is not even agreement about what to call it - stammering being the preferred term in the UK. What is known is that it has a genetic cause in 75 per cent of cases, and results from problems with motor control of muscles in the throat and mouth, or from errors in brain programming and coordination. There is a good success rate - about 90 per cent - for sufferers who receive early treatment.
To date, no one has been able to pinpoint a single underlying cause for stuttering although most experts agree that stuttering is likely to be a disorder of motor coordination development in the brain - that is, a problem with the neural processing that underlies speech production.

Some new research

Researchers at Macquarie University's Centre for Cognitive Sciences (MACCS) are trying to fill the gaps in our knowledge using innovative technology. They are using a unique MEG or magnetoencephalography system to explore language acquisition and auditory processing in children who are too young to participate in behavioural studies. The brain imaging technique is able to measure the tiny magnetic field generated whenever information is processed by the brain - in this case as a child watches and responds to a series of pictures in short sessions.

Types of stuttering

Stuttering refers to more than one kind of vocal production. There are three identifiable types:

Repetition - The most common stutter at any age is repetition of sounds, syllables or words/phrases e.g. "and, and, and" or "but, but, but" or "it can be, it can be, it can be". If mild, there may be only a few repetitions but in more severe cases, it can be 15 to 20 times.

Prolongation - Sounds are drawn out... "ssssssssssssssssssss"

Block - This is the most difficult type of stutter to overcome. The sufferer knows what they want to say but often nothing comes out, making it the most frustrating type of stutter. Somewhere in the vocal tract, things are locked up. It may be no airflow at a laryngeal level or in the mouth. Sometimes it feels as if the tongue is stuck to the roof of the mouth.

The teenage protagonist of the novel Black Swan Green by British novelist David Mitchell suffers from this last kind of stutter. He nicknames his block "Hangman", such is the dread he feels at the prospect of trying to produce sounds that he knows are problematic.
With progress in research techniques, and the attention The King's Speech has brought to stuttering, there is hope that scientific breakthroughs and raised public awareness will help to bring relief to the many sufferers of this age-old condition.

Project:Stuttering Treatment for Preschool Children

Research Centre: Centre for Language Science

Stuttering is a language disorder that typically begins when children are 3- or 4-years-old. Stuttering affects children across all languages and cultures. Speech pathology researchers in Australia have developed a treatment for stuttering called the Lidcombe Program. CLaS researcher Dr Elisabeth Harrison and her colleagues are investigating the Lidcombe Program as part of a collaborative research project funded by an NHMRC Program Grant to the Australian Stuttering Research Centre at the University of Sydney. 

During treatment, parents learn to provide feedback to children, to help them reduce their stuttering. The project aim is to identify the specific kinds of comments that result in the greatest reductions in stuttering. This will improve the Lidcombe Program by enabling speech pathologists to train parents more quickly and effectively, thereby reducing overall treatment time and cost.

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