Autistic Speech and Prosody

Differences in Tone, Rhythm, and Intonation Can Affect Communication

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Spoken language involves more than the use of words; we vary our pitch, loudness, tempo, and rhythm in our speech in order to convey different meanings. These changes are called "prosody," and people with autism often find prosody difficult to hear, understand, or reproduce. What this means is that even people with very high functioning autism or Asperger syndrome may not truly understand what is being said, or may say things in such a way that they are misunderstood.

Making Sense of Prosody

To better understand how prosody works (and why it's so important), try saying the word "really" five times in a row, but change the meaning each time as follows:

  • How cool is that?!
  • I don't believe you.
  • I'm shocked.
  • I'm delighted.
  • I'm telling the truth.

If you did this exercise, you changed your prosody at each repetition of the word -- even though your pronunciation of the word (REE-lee) remained the same. In some cases your voice went up or down on different syllables or to a varying degree; in other cases, your voice was louder, quieter, faster, slower.

Others' Use of Prosody Can Be Confusing for People with Autism

When people with autism use spoken language, they usually use it quite literally. As a result, sarcasm, irony, idioms, metaphors, and similes may go right over their heads. 

It's easy to understand why this would be the case. For example, statements like these can mean many different things depending on tone, context, and body language -- and misunderstanding can have serious consequences.

  • A friend says "I love you!" (but means "I love the fact that you agreed to do something for me")
  • A co-worker says "Are you really done with this project?" (but means "you didn't finish this project, and should recheck for errors)
  • A store clerk says "You have to buy this" (but means "I want you to buy this, and am trying to persuade you to do so)

    It Can Be Hard for Autistic People to Properly Use Prosody

    Because many people with Asperger syndrome or high-functioning autism are very bright and have huge vocabularies, difficulties with prosody and language use aren't always obvious -- because the speaker isn't obviously disabled. The outcome is that conversational partners may be unintentionally offended or confused, resulting in hurt feelings and negative interactions.

    In addition, people with autism may find it very hard to use prosody to express multiple or subtle meanings -- thus limiting their own ability to communicate.This can lead to a myriad of social communication issues ranging from embarrassing gaffes to accusations of verbal assault or stalking.

    Another issue related to problems with prosody is a "flat" voice, sometimes misinterpreted as ​a lack of interest, lack of intelligence, lack of humor or lack of emotional response. In fact, many people with autism are extremely emotionally sensitive; many are artists, poets, and composers whose emotional sensitivity comes out in their art. And many people with autism have terrific senses of humor. But a flat voice, combined with a lack of verbal expressiveness, can easily be misinterpreted.

    Resources for Improving Use of and Understanding of Prosody

    There are no full-fledged therapies developed to help people with autism overcome deficits in prosody, though experimental approaches are under investigation -- including interaction with specially built and programmed robots. If you are interested in exploring possible directions for improving prosody, you may wish to explore:

    Learn More About Autism Symptoms, Types of Autism and Autism Diagnosis


    ML Bellom-Harn,et al. "Research: Targeting Prosody in an Eight-year-old Child with High-functioning Autism during an Interactive Approach to Therapy." Child Language Teaching and Therapy, Volume 32, Issue 2, p. 157-179, (2007).

    JJ Diehl. "Resolving ambiguity: a psycholinguistic approach to understanding prosody processing in high-functioning autism." Brain Lang. 2008 Aug;106(2):144-52.

    J Heikkinen et al."Perception of basic emotions from speech prosody in adolescents with Asperger's syndrome." Logoped Phoniatr Vocol. 2010 Oct;35(3):113-20.

    Brian Scassellati. "How Social Robots Will Help Us to Diagnose, Treat, and Understand Autism." Springer Tracts in Advanced Robotics, 2007, Volume 28/2007, 552-563.