Phonological Processes

Phonological processes are speech sound error patterns that children use to simplify speech. Unlike articulation errors, which occur when a child has difficulty producing one or two specific speech sounds, phonological processes are error patterns that can occur across groups of sounds.

For example, in the pattern called “fronting,” all “back sounds” (sounds made in the back of the mouth like k and g) may become “front sounds” (sounds made in the front of the mouth like t and d). Similarly, with the process called “stopping,” many “long sounds” (such as fricatives like s, z, and f) may become “short sounds” (such as stops like p, t, and d).

It is normal and expected for very young children to simplify speech sounds until a certain point. In fact, many of these patterns are considered typical until around age 3. However, as communication develops, these errors are expected to fade away, and the majority of phonological patterns should disappear altogether by age 5. A child may have a phonological disorder if:

• They continue to use phonological processes past the typical age of elimination
• They exhibit many patterns at the same time, resulting in significantly reduced speech intelligibility (meaning it is very difficult to understand them)

Signs of a Phonological Disorder

• Consistent speech errors that seem to follow a pattern
• Difficulty with early skills related to reading (such as rhyming, blending sounds, etc.)
• Difficulty noticing the difference between similar sounds

Common Phonological Processes

The table below provides information regarding some of the most commonly occurring phonological patterns. The age of elimination indicates the typical age by which the process should fade away.

Pattern	Definition	Example	Age of Elimination
Fronting (velar)	Back sounds (k, g) replaced by front sounds (t, d)	“tar” for car	3;6
Fronting (palatal)	Palatal sounds (sh, zh) replaced by alveolar sounds (s, z)	“su” for shoe	4;6
Stopping	Fricatives or affricates replaced by stops	“tun” for sun	3;0–5;0
Final consonant deletion	Consonant at the end of a word is omitted	“bo” for boat	3;3
Initial consonant deletion	Consonant at the beginning of a word is omitted	“at” for cat	3;0
Weak syllable deletion	Unstressed syllable in a multi-syllable word is omitted	“nana” for banana	4;0
Cluster reduction	One or more consonants in a cluster are omitted	“top” for stop	4;0–5;0
Gliding	Liquids (l, r) replaced by glides (w, y)	“wabbit” for rabbit	5;0–6;0
Deaffrication	Affricates replaced by fricatives	“ship” for chip	4;0
Vocalization	Syllabic consonant replaced by a vowel	“botto” for bottle	5;0
Assimilation	One sound becomes more similar to a nearby sound	“gog” for dog	3;0
Backing	Front sounds replaced by back sounds	“gog” for dog	Not typically observed
Stridency deletion	Strident sounds (f, s, sh, ch) are omitted or replaced	“top” for stop	Not typically observed
Reduplication	A syllable is repeated to form a word	“wawa” for water	2;6
Affrication	Non-affricate replaced by an affricate	“choe” for toe	Not typically observed
Addition	Extra sound added to a word	“doguh” for dog	Not typically observed

Sources: Bowen, C. (1998). Developmental phonological disorders: A practical guide for families and teachers. Melbourne: ACER Press. Stoel-Gammon, C., & Dunn, C. (1985). Normal and disordered phonology in children. Austin, TX: Pro-Ed.