Sure, you’ve heard it all in graduate school, but what IS the difference between an articulation disorder and a phonology disorder? I know you knew it "once upon a time," but what do you do when you’re confronted with a child who has unintelligible speech? Do you treat it as an articulation or a phonology disorder? Hopefully, the following information will help you decide.

What is the difference between articulation and phonology? Webster’s Dictionary gives one definition for articulate as, "to produce, by a speech sound, by the movement of the organs of speech." Articulation refers to the movement of the speech mechanisms (tongue, lips, larynx, teeth, hard palate, velum [so air escapes through nose only when appropriate], jaw, nose, and mouth) to produce speech. If any of these mechanisms are not working properly, weak, damaged, malformed, or out of sync with the rest, then a speech disorder may be classified as an articulation disorder.

Phonology, on the other hand, encompasses the rules of the sound system of language. These rules over-see speech sounds, including the production and combination of these sounds into intelligible speech. What happens if one or more of these rules is broken? It may result in fronting, which happens when a sound (like /g/) that is produced in the back of the mouth "breaks the rules" moves to the front, and comes out /d/. Or when a sound that only lets a little air escape when following the rules (like /s/) acts up and stops, becoming /t/ (stopping). How about sounds that want to be so much like the sounds around them, that they become them (assimilation – Cat becomes Tat)?

Well, here’s the good news. Children with normally developing speech skills generally break these rules (patterns) when speech is developing. However, it’s when one or more of these persist that a phonological disorder develops. Children with disorders of phonology have difficulty adhering to the rules of speech, but they don’t necessarily have articulation disorders. Their speech mechanisms may be moving properly, but just not following the rules of speech production. This could make speech virtually unintelligible and negatively impact the child’s academic and social success.

The next part of the process is to examine the child’s speech. There are a variety of ways to do this. After a child is referred for a speech and language evaluation, many therapists opt for standardized assessments using picture plates. These are fine, but be sure not to count these as the “end all” of the assessment. If time permits, engage the child in conversation and record his/her speech on a quality tape recorder. Then, analyze the recording and obtain a speech sample of at least one hundred words.

If all articulators appear intact, undamaged, and working properly, the next step is to administer a phonological processes analysis. First, look over the initial articulation assessment to get a preliminary idea of the child’s speech production; keep in mind that the child may have scored within "normal" range on this test due to the targeted phonemes. (For example, if a child had the phonological process, "final consonant deletion," he/she would only be scored against on phonemes in the final position.) Then, administer the analysis of the child’s phonological processes, using a number of available assessments on the market.

Once you determine whether a child has an articulation or phonology disorder, then you may choose the most appropriate therapy approach for that child. Remember, there IS a difference between an articulation and phonology disorder; your knowledge and choice of treatment plans are essential for success in therapy, the classroom, and at home. Good luck!