Explaining “Articulation” and “Oral Motor”

By Pam Marshalla

Q: I have been arguing with a colleague about “oral motor” and “articulation.” She does not seem to know what an articulation deficit is. She disputes the notion of an “articulation deficit,” and claims that there are only “phonological deficits.” Can you help me? I know what I mean, but I can’t seem to put it in the right words for her to grasp. I need help explaining what an “articulation deficit” is, and help in relating this to “oral motor.”

In my opinion, this is all a matter of perspective.  One can view a client’s inability to produce /k/ as in the word “cookie” as a phonological deficit, an articulation deficit, or an oral-motor problem depending upon one’s view.  Perhaps the following explanations will help. I have put my advice at the close.

Articulation Deficit

The traditional definition of “articulation” comes from speech science, and it goes something like this:  Speech is the coordinated effort of four speech movement subsystems––

  • Respiration refers to the movements of breathing for speech.
  • Phonation refers to the movements of the vocal folds and larynx for speech.
  • Resonation refers to the movements of the velopharyngeal mechanism for speech.
  • Articulation refers to the movements of the jaw, lips, and tongue for speech.

Following the above, and strictly speaking, an “articulation deficit” therefore is a speech defect (1) that is the result of incorrect jaw, lip, or tongue movement. The term “articulation deficit” has been generalized through the years, however, and has been used to refer to any and all problems in phoneme production.  For example, children who inhale instead of exhale on /s/ are classified as having an “articulation deficit.” But strictly speaking, this is an inability to control respiration, not articulation.

Oral Motor

The term “oral motor” simply is a term used to discuss “mouth movements” and therefore it means the same thing as “articulation.”  Both of these terms refer to improper movements of the jaw, lips, and tongue.(2) An “articulation” deficit is a speech problem that is the result of incorrect “mouth movement” or “oral movement.”  Thus an “articulation deficit” is an “oral motor problem.”

Phonological Deficit

The term “phonology” refers to the way in which phonemes are used within a language––“The part of linguistics concerned with ‘putting together’ or ‘putting sounds into words” (Bernthal and Bankson, Articulation and Phonological Disorders. Boston: Pearson, 2004, p. 47). However, over time and since the 1970s, the term “phonological deficit” has come to refer to any and all problems with phonemes. Therefore, many modern professionals use the term “phonological deficit” today to encompass any phoneme problems.

Distinctive Features

When the study of phonology entered the field, it began with a discussion of “distinctive features” or “phonetic features”: “The totality of phonetic features can be said to represent the speech-producing capabilities of the human vocal apparatus” (Reference: Chomsky and Halle, 1968, The Sound Patterns of English). What are the “speech-producing capabilities of the human vocal apparatus”? Put most simply, they are movements: A human can close the mouth, open the mouth, lift the tongue-tip, lift the tongue-back, lift the velum, exhale, and so forth. These movements comprise speech.

It’s All The Same Thing

In my opinion, we should stop arguing about all this because these are all different terms to describe the same thing. Take the client who cannot produce /k/ and who substitutes t/k. We can view this from any of the perspectives offered above––

  • Articulation: The error is one of substituting one phoneme for another. We have to teach him to produce /k/ instead of /t/.
  • Oral-motor: The error is the result of an inability to lift the back of the tongue. We have to teach the client to lift the back of the tongue instead of the front of the tongue to produce /k/ instead of /t/.
  • Phonology: The error is one of fronting: of opening syllables only or predominantly with front consonants. We have to teach the client to open syllables with /k/ as well as /t/.
  • Distinctive Features: The error is one of making the target [-Back] when it should be [+Back], and so forth.


Is it not completely obvious that this is all the same thing? We are fighting over vocabulary words. My advice to you is to let your colleague think whatever s/he wants to think. What does it matter what the error or the correction process is called? Just do therapy the way you think it should be done and let your colleague do likewise. Congratulate your colleague for the excellent work s/he is doing by pointing out how good the clients sound: “Wow! You have really done a great job with Billy and Sally! They sound a lot better!” When s/he criticizes your perspective, simply say, “That’s an interesting perspective… I’ll think about that…” and move on. Celebrate the diversity of perspectives, and honor the similarities. Consider sharing this QA with the whole staff, but don’t assume this person will change because of it. Remember: Every person opens his or her own eyes.


  1. Van Riper’s definition of “defective speech” has stood the test of time: “Speech is defective when it deviates so far from the speech of other people that it calls attention to itself, interferes with communication, or causes its possessor to be maladjusted.”  Reference: Van Riper, C. (1939) Speech Correction: Principles and Methods. Englewood Cliffs: Prentice-Hall.
  2. The term “oral motor” began to be used in the 1970s when SLPs began to work together with OTs and PTs who already were using the terms “gross motor” and “fine motor.”  The term “oral motor” allowed us to begin to talk with OTs and PTs about “articulation” in speech.  This was a concept that was new to OTs and PTs because at the time motor professionals were using the term “articulation” only to refer to the relationship of one bone to another. (For example, the femur “articulates” with the pelvis at a ball and socket joint known as the acetabulofemoral joint.) When OTs and PTs heard the term “articulation” in reference to speech, they immediately thought of the temporomandibular joint. They did not view “articulation” the way we do––as in the “articulation” of the “articulators.”  The term “oral motor” helped us begin to speak with OTs and PTs about oral movement in speech and feeding.

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