Autism and speech

Kathleen Scaler Scott is Associate Professor at the Department of Speech-Language Pathology, Misericordia University.  She explains what fluency disorders are, how they may present in autistic people and what speech and language therapists (SALTs) can do to assist.

Author: Kathleen Scaler Scott
Autism and disfluent speech
For decades, researchers have identified patterns of “disfluent speech” in autistic individuals, i.e. speech that exhibits deviations in continuity, fluidity, ease of rate and effort, with hesitations or repetition of sounds, words, or phrases. More recently, the nature and presence of this disfluent speech has become clearer. Three different types of disfluency have been identified:
Stuttering occurs when a person is clear on the words they would like to say, but physically has difficulty getting these words out. People who stutter have difficulty moving forward in producing their words and may: 
  • repeat sounds(s-s-s-speech) 
  • repeat syllables (ru-ru-running)
  • prolong sounds (sssspeech, whaaat)  
  • become 'stuck' (blocked) on a sound (s------speech)
During a stuttering block it will take time for the word to come out, and during the block struggled attempts at sound production may be heard, or there may be silence. 
Cluttering occurs when a speaker speaks at a rate that is too fast for their system to handle. Those who clutter sound fast to the listener, and listeners have difficulty understanding the person with cluttering due to the presence of at least one of three symptoms: 
  • excessive repetitions of phrases, revisions of ideas, filler words such as “um” or “uh” 
  • excessive over-coarticulation.  Sounds in words run together and sounds or syllables may be deleted. For example, “It’s like this” may sound like, “slikethi.”
  • pauses in places where they would not be expected grammatically. 
Atypical disfluency
Atypical disfluencies occur when the speaker has easy repetitions or prolongations of sounds at the ends of words (speech-eech, light-t, misssss) or inserts a sound in the middle of a word (e.g. boy becomes (boy-hoy.). 
Research is in its infancy regarding these atypical disfluencies. Observations among researchers suggest that these disfluencies differ from stuttering in that the repetitions often occur after the speaker has completed the word. 
Whereas the individual with stuttering has difficulty starting a word, a speaker with atypical disfluency seems to have difficulty ending the word. Sometimes the end-of-word repetitions occur immediately (speech-eech) and other times after a pause (speech (pause) -eech). 
The length of the pause varies between individuals, and some have been known to insert another thought in between the pause and the repetition (e.g., “Can you turn out the light (“Oh I like that book”; pause) -ight so I can go to sleep?”). 
Life impact
In addition to the outward symptoms of disfluencies, some speakers experience negative feelings and perceptions about their difficulties. Although these negative feelings and perceptions are most common among those who stutter, feelings such as shame, embarrassment, or fear can also occur in response to cluttering, or atypical disfluencies.
Additionally, speakers may have cognitive misperceptions about their fluency disorder, such as thoughts that they will always stutter when they say their name, or that they will never be able to be employed in a career that involves speaking. These negative feelings and perceptions can lead to communication avoidance. Individuals with stuttering, in particular, may exhibit tension in their face or other areas of the body when attempting to speak. 
Disfluency in autism
Awareness of disfluency is variable in many autistic people, especially among those who clutter and/or exhibit atypical disfluencies. It is important to note that awareness occurs along a continuum. Each person should be assessed as an individual to determine which factors may be contributing to difficulties with efficient and effective communication and therefore may need to be addressed in treatment. 
Speech and language professionals specifically trained in assessment and treatment of fluency disorders can help with assessing disfluency and any accompanying characteristics. It is important to remember that multiple types of disfluencies can present themselves in the same speaker.
Although research continues to emerge, all types of disfluencies have been found in pre-schoolers, school-age children, teens and adults on the autism spectrum. Disfluencies have also been identified across all cognitive abilities. The overall negative impact upon communication should be considered when prioritising goals for speech and language therapy. Communication avoidance and limits to social interaction should be red flags for prioritising fluency assessment and possible therapy.
How speech and language therapy can help autistic individuals
The first thing that a speech and language therapist (SALT) can do is to help identify any disfluencies by type. If there is negative life impact, the SALT can work with the client. If the SALT is not comfortable working with fluency disorders, they can refer the individual to someone experienced in treating fluency disorders.
  • If stuttering, treatment strategies will focus on changing the timing and tension of speech.
  • If cluttering, treatment will focus upon rate regulation through natural pausing and emphasis of sounds for clarity.
  • If atypical disfluency, the proposed function of the disfluency will be determined and the corresponding underlying “root” cause(s) may be addressed. For example, if a client seems to be repeating the end of a word to hold their place due to difficulties with word finding, the SALT may work directly on word finding to eliminate the need to hold their place, as well as natural pausing (instead of repetition) to hold their place when more time is needed.
Further reading
For review of disfluencies in autism spectrum disorders, see:
Scaler Scott, K., Tetnowski, J. A., Flaitz, J., & Yaruss, J. S. (2014, Jan-Feb). Preliminary study of disfluency in school-age children with autism. International Journal of Language and Communication Disorders, 49(1), 75-89.
For therapy management techniques for cluttering, including cluttering in the ASD population, see:
Scaler Scott, K., & Ward, D. (2013). Managing Cluttering: A Comprehensive Guidebook of Activities. Austin, TX: Pro-Ed, Inc. 11
For more information regarding assessment, differential diagnosis, and treatment of individuals with fluency disorders and other diagnoses including autism, see the forthcoming guide:
Scaler Scott, K. (in press). Fluency Plus: Managing Fluency Disorders in Individuals with Multiple Diagnoses. Thorofare, NJ: SLACK, Inc.
Date added: 13 July 2017



Thu, 27/07/2017 - 20:56

Hi Kathleen,

what would you describe it when an individual with Asperger's has periods of speaking very rapidly (to the degree the listener is somewhat dumbfounded and points out the lack of intake of breath during this rapid speech) but who doesn't possess any of the 3 listed elements of cluttered speech?  This rapid speech is not due to stress or anxiety in the individual, it is a natural speech pattern which happens randomly and for no specific reason.  The individual may have rapid thought processes and wish to get everything there is to say out, bearing in mind the detailed and verbose nature of the Asperger's individual, it is almost sensible to speed up the rate of speech to ensure it is all included.  The individual doesn't see it as a problem, but it is definitely noticed by others, who may lose track of what the Asperger's person is saying because they are so fascinated by the speed of speech or their brain cannot process the topic due to the speed.

Does this also constitute cluttered speech as the words are cluttered together through being spoken rapidly?

Also, what would be your comment regarding professionals who are not autism aware (trained) therefore do not understand that this speech is a feature of the Asperger's and not 'pressure of speech' that someone may have with high anxiety (in other words, not a sign of mental ill-health but a natural order of speech for someone with Asperger's)?


Tue, 19/09/2017 - 12:08


  Thanks for your interesting question. If the individual doesn't meet any of the 3 criteria for cluttering (i.e., excessive repetitions and/or revisions and/or fillers, words run together with sounds left out, or pauses in unexpected places) then they could not be considered to meet the diagnostic criteria for cluttering. Keep in mind that they don't have to exhibit these features all the time to be diagnosed, cluttering can be situational. But perhaps this is a case where the person speaks rapidly but is not at all unintelligible (either in actual speech sounds being produced or in content of message)? I think you may be saying just that the listener may need more time to process their message? If so, I have taught individuals like this to work on increasing natural pausing. If they don't need the pausing to help them formulate a message or articulate it clearly, I tell them to consider that their listener might need the pausing for processing time. For the same reasons, if they are not efficient in communication (using more words than needed to communicate a message), I may work with them on increasing the efficiency of their message (w/o changing the content of it) order to help their listener process and understand. 

   Fluency specialists always find themselves advocating that there is little relationship between mental health/anxiety and fluency disorders. I tell professionals that although it may sound like someone is anxious when they stutter, or that stuttering may make a person more anxious or stressed out (as a natural reaction to having trouble with your speech rather than an anxiety based in a mental illness), the origin is not mental health. I know you are not talking about stuttering in Asperger's, but maybe the same concept can be explained in your case....i.e., the pressured speech may sound like someone is anxious, but there is no research to support that it is based in anxiety. Hope it helps.