Stuttering and Cluttering

What is Stuttering?


Stuttering is a speech disorder where the smooth flow of speech is disrupted. This dysfluency may interfere with the ability to be clearly understood.


Some types of stutters include:

  • Repetitions of sounds, syllables or words e.g. “M-m-m-mummy” or bu-bu –bubbles or ‘I want- I want-I want a pear”.
  • Blockings that are silence as the person tries to speak.
  • Prolongations e.g. “Where is the c-o-o-o-w?”
  • Verbal disruptions may be accompanied by body, head and facial movements such as eye-blinking or other signs of struggle and tension.


What Causes Stuttering?

The causes of stuttering are multifactorial. Stuttering has been strongly linked to a genetic basis. Stuttering also affects more males than females, with reported rations varying from 3:1 to 5:1 (Onslow, 1998).  In addition, brain studies have also shown differences in the brains of people who stutter, compared to the normal individuals.

Stuttering may also be influenced by environmental factors and may worsen in situations that produce anxiety or stress.


Onset of Stuttering

The onset of stuttering typically occurs in the early years of life, between 2 to 5 years old or as soon as a child starts putting words together into short sentences. Sometimes, stuttering may be ‘acquired’ in late childhood or early adulthood. “Acquired” stuttering may occur due to psychogenic reasons or neurological trauma such as a head injury or stroke.


What happens in Speech Therapy?

Parents may be concerned that stuttering therapy will increase the child’s awareness of his or her speech dysfluencies and have a negative effect. Deciding to bring your child for treatment is an important step towards helping your child.

Stuttering therapy allows children to successfully speak fluently, resulting in:

● Increased confidence
● Stuttering with less tension
● Increased eye contact


Stuttering Treatment

Preschool and school-aged children are treated using the Lidcombe Program. The Lidcombe Program is an evidence-based, behavioural treatment for early stuttering. Parents are trained to help their child to control their stutter. Results from the Lidcombe Program show that the majority of children are able to maintain fluent speech during conversations or social interactions.

For adolescents and adults, Prolonged or Smooth speech techniques are used. Clients are taught specific strategies to improve their fluency and control the stutter. Treatment is conducted on an individual basis and tailored to suit the client’s needs. This may include reading, presentations, speaking engagements, job interviews, or other social situations.


Great Stuttering Resources

Australian Stuttering Research Centre :
Latrobe University :


What is Cluttering?
Cluttering is another fluency disorder that is less well-known. Individuals with cluttering often speak at an unusually fast rate; they may also repeat syllables or words. Prosody and articulation may also be affected. For instance, an individual may display articulation difficulties, such as “buttercup” as “tuttertup”, or omit sounds in words “crocodile” as “crodile”.

Differences between Stuttering and Cluttering

Symptom Stuttering Cluttering
What gets stuck Word, sound, syllable Message
Know what want to say?




No (or less clear; know but theyget derailed in mazes)




Typically yes


Yes and No


Rate differences


Can be a secondary strategy (i.e. person who stutters may speak quickly to avoid stuttering), but is not central to stuttering itself


Yes; mandatory for a diagnosis of cluttering (note that rate has to be rapid OR irregular, but does not have to be both)


Dysfluences Mostly stuttering-like disfluencies (SLDs), such as repetitions, prolonga­tions, blocks


Mostly non- stuttering- like disfluencies (NSLDs), such as interjections / filler words, phrases repetitions, revisions


Examples of dysfluencies:


Repetitions of sounds of syllables:
y-y-you, wa-wa-watermelon
Prolongations: sssso; thiiiis Blocks: sound gets stuck and person has difficulty moving forward to nextsound: p—eople
Interjections/ filler words: um, uh
Phrase repetitions: I love, I love NSA
Revisions: I would like ice cream, no, please make that a shake
Articulation difficulties
(i.e. difficulties pronouncing sounds in words)
Not in pure stuttering (i.e. stuttering without any additional communication disorders) May sound “Mushy” and “Slurred”, typically can be corrected by such strategies as slowing down one’s speech rate
Prosody (i.e. the rhythm and melody of one’s speech) Typically normal May be impacted; especially by change in pausing related to irregular rate.
How it sounds Repetitions, prolongations, blocks Rushes of speech; lots of restarts
Affective and cognitive components


Can be


Negative reactions and communication avoidance have been identified by consumers
Pragmatics (i.e. social aspects of language) Typically okay A secondary consequence to decreased communication effectiveness.


Reference: National Stuttering Association, 2010

Read more: