Teaching Co-articulation Movements

By Pam Marshalla

Q: I have a student, who has been working on R, and who can make it at the word and sentence levels, but who cannot seem to co-articulate automatically. He still articulates each sound individually within words. For example he does not automatically round his lips for the word “core.” When I say the word “core” my mouth stays rounded for the entire word however they don’t do this. Why don’t their minds just naturally catch on to coarticulation after so many years of diligent work?

My contention has been for many years that the inability to generalize newly learned articulation skills is what makes some of the hardest clients so hard. We probably never will know why. Their brains simply don’t do this on their own. Therefore some of our most difficult clients need to be led slowly and carefully through all levels of therapy including the level at which co-articulation occurs.

The motor speech scientists of the early 20th century(1) argued that the syllable (and not the phoneme) was the basic motor unit of speech. They said that the vowel was the main “movement” or “shape” of the syllable, while the consonants were “auxiliary” or “additional” movements added to the basic shape. They said that when we produce a syllable, the mouth first shapes itself for the vowel, and it holds this shape while the consonants are added to it. The reason your lips stay round throughout the word “core” is because the mouth assumes the O position first, and it holds this position while C and R are added to it.

This is what I do to teach this skill:

  1. Teach the client to make and prolong an exaggerated O.
  2. Then have him hold the O sound while he moves his tongue into and out of R position in sequences. He is holding the entire mouth in the O shape, not just the lips. He will end up saying OOO-R-OOO-R-OOO-R-OOO… with the mouth in the O shape the entire time.
  3. Now do this with other vowels.
  4. Now ad a consonant before the vowel. For example, have him say OOO-R-DOO-R-DOOO-R…
  5.  Now do this with several different vowels and several different consonants.

Now you are truly teaching what McDonald(2) called the “overlapping ballistic movements” required in co-articulated speech. You are taking the focus away from R and the vowels, and putting focus on the movements of the syllables. The syllable is made by shaping the mouth for the vowel, and by then adding consonant movements to that basic shape.


  1. For example: Stetson, R. (1928) Motor phonetics. USA: North Holland Publishing. Stetson can be read today in: Kelso, J. A. S., & Munhall, K. G. (Eds.) (1988).  R. H. Stetson’s motor phonetics: a retrospective edition. Boston: College-Hill.
  2. McDonald, E. T. (1964) Articulation testing and treatment: A sensory-motor approach. Pittsburgh: Stanwix House.


0 thoughts on “Teaching Co-articulation Movements”

Leave a comment!

Keep the conversation going! Your email address will not be published.