Articulation versus phonology… What is the difference when it comes to speech and language?


An articulation disorder is when there are speech sound errors like saying the “w” sound instead of the “r” sound, e.g. “wabbit” instead of “rabbit” (Hey, Bugs Bunny!) beyond the typical age of acquisition. Other examples of articulation disorders include leaving off a sound like saying “at” instead of “that,” or when a sound just doesn’t sound quite right, like it is distorted. In articulation disorders, the speech sound errors are often consistent for a certain sound or sounds, like "s" or "t."

In summary: motor aspects contribute to speech sound disorder; problems with certain sounds

Age (years) 50% of children have sound mastered 90% of children have sound mastered
<2 p, m, h, n, w, b -
2-2.5 k, g, d, t, ng, f, y -
3-3.5 r, l, s, ch, sh, z p, m, h, n, w, b
4-4.5 j, v, voiceless th k, g, d, f, y
5 voiced th -
6 zh t, ng, r, l
7 - ch, sh, j, voiceless th
8 - s, z, v, voiced th, zh

Source: ASHA


A phonological disorder is when there are speech sound errors that are predictable and follow a pattern, known as a phonological process (sometimes called a phonological pattern). An example of a phonological process is when an individual leaves off the last syllable of a word, no matter what sound is at the end of the word. They may say “bo” for boat, and “duh” for duck.

In summary: linguistic aspects contribute to speech sound disorder; pattern of sound mistakes

Age (years) Phonological process eliminated Example(s)
3 velar assimilation
nasal assimilation
stopping (f and s)
final consonant deletion
"kack" vs "tack"
"nunny" vs "bunny"
"pun" vs "fun"
"no" vs "nose"
4 fronting
stopping (z and v)
cluster reduction (without s)
weak syllable deletion
"tar" vs "car"
"doo" vs "zoo"
"ship" vs "chip"
"keen" vs "clean"
"nana" vs "banana"
5 stopping (sh, ch, j, th)
cluster reduction (with s)
"dump" vs "jump"
"top" vs "stop"
6-7 gliding "weg" vs "leg"

Source: ASHA

There are cases when an individual has a purely articulation OR phonological disorder, but it is not always possible to clearly differentiate one or another. For this reason, SLPs sometimes use the term speech sound disorder to encompass both of these factors.

A speech sound disorder is defined by ASHA as having difficulty producing speech sounds and segments. Speech sounds disorders may be organic (e.g., motor/neurological, sensory, structural) or functional (i.e., no known cause) in nature.

Want more of an in-depth explanation of speech sound disorders? Check out our article titled: What is an Articulation Disorder? An Overview of Speech Sound Disorders.