Articulation vs. Phonology

Speech sound disorders are very common (around 10-15% of children ages 3-6 have them!). However, there are different types of speech sound disorders, and the nature of the disorder is very important in how we decide to move forward with speech therapy. There are three main types of speech sound disorders: articulation, phonological, and motor speech. In this post, we will dive into the difference between articulation and phonological difficulties. We will not be discussing motor speech disorders (e.g., Childhood Apraxia of Speech; Dysarthria).

A phonological disorder and an articulation disorder both involve difficulties with speech sounds, but their underlying causes differ. An articulation disorder affects the physical production of sounds—how the sounds are actually produced. For example, a child may produce /s/ with their tongue consistently in an atypical position, resulting in a “slushy” sound. We often confuse all speech sound difficulties as articulation difficulties. I frequently hear families say, “I don’t understand! He says the /k/ sound perfectly, but then says “tat” for cat!” This is so very common, and the reason is that this child is not having an articulation difficulty at all! This is a great example of a phonological error.

A phonological disorder affects patterns of speech sound errors based on rules or conventions of the language. All kids make phonological errors as they learn the patterns of speech, but a disorder occurs when children do not grow out of these patterns as they get older. Here are some examples of phonological patterns and the ages we expect them to go away:

• Final Consonant Deletion (usually gone by 3 years): Omitting the final consonant in words. For example, saying "ca" for cat or "do" for dog.

• Cluster Reduction (usually gone by 4-5 years depending on the cluster): Omitting one or more sounds in a consonant cluster. For example, saying "poon" for spoon or "pane" for plane.

• Fronting (usually gone by 3.5 years): Substituting a sound made in the back of the mouth (like /k/ or /g/) with a sound made in the front (like /t/ or /d/). For example, saying "tat" for cat or “do” for go.

• Stopping (usually gone by 3 for /s/, and later for other fricatives): Replacing a fricative sound (like "s") with a stop sound (like /d/). For example, saying “dope” for soap.

• Weak Syllable Deletion (usually gone by 4 years): Omission of an unstressed syllable in multi-syllable words. For example, saying "nana" instead of banana.

• Gliding (usually gone by 6 years): Replacing /l/ or /r/ sounds with a /w/ or /y/ sound. For example, saying "wing" for ring, “wion” for lion or “yeyo” for yellow.

• Check out this comprehensive chart from Little Bee Speech!

In summary, a phonological disorder includes difficulties with understanding and using sound patterns, while an articulation disorder includes difficulties with the physical production of specific sounds. It is possible to have both phonological and articulation errors. Regardless, it is important that we know the underlying causes of speech sound disorders, because treatment is different based on the nature of the disorder. If we approach a phonological disorder with articulation therapy, the child will not make progress in speech therapy. In addition, it is crucial that children have strong knowledge of their phonological system for the purposes of decoding and encoding (reading and spelling) — but that’s a topic for another day!