"Articulation." "Phonological processing." "Phonological disorder." "Speech sound disorder." These terms get used almost interchangeably in staffrooms, GP rooms and Facebook parent groups — but inside speech pathology, they describe genuinely different things, and the difference changes everything about how therapy is structured.
This article is the "definitions" hub of our speech sound cluster. If you've read one of our other pieces — on delayed patterns, atypical errors, or disordered production — and come away wondering what "phonological" actually means versus "articulation," this is the article that untangles it. It's also the one to read if you've been told your child has one type when you thought it was the other.
What Are Articulation Errors?
Articulation errors are about the physical production of individual sounds. Think of it as a motor skill — your child's tongue, lips, or jaw aren't quite getting to the right place to make a specific sound clearly.
A classic example is a lisp, where a child produces "s" with their tongue poking forward between their teeth, so "sun" sounds more like "thun." The child knows the sound they want to make — they just have difficulty getting their mouth to cooperate for that particular sound.
Key features of articulation errors:
- They usually affect one or two specific sounds
- The error is consistent — the sound is produced the same (incorrect) way every time
- It's a motor-based difficulty — the muscles and movements of speech are involved
- The child may be able to hear the difference between the correct and incorrect sound
What Are Phonological Processing Errors?
Phonological processing errors are different. These are about the patterns and rules a child uses to organise sounds in their speech. Rather than struggling with one sound, the child is applying a "rule" (called a phonological process) that affects a whole group of sounds.
For example, a child might replace all sounds made at the back of the mouth (like "k" and "g") with sounds made at the front (like "t" and "d"). So "car" becomes "tar," "go" becomes "do," and "cup" becomes "tup." That's not a motor problem with one sound — it's a pattern affecting an entire category of sounds.
Key features of phonological processing errors:
- They affect groups of sounds, not just one
- The errors follow predictable patterns (phonological processes)
- It's a language-based difficulty — how the child's brain organises the sound system
- The child can often produce the individual sounds correctly in some contexts but not others
Common Phonological Processes
Phonological processes include things like fronting ("car" → "tar"), stopping ("sun" → "tun"), cluster reduction ("spider" → "pider"), final consonant deletion ("cat" → "ca"), and gliding ("rabbit" → "wabbit"). Many of these are perfectly typical in younger children — a two-year-old saying "tar" for "car" is right on track. It's when they hang around past the expected age that we start to pay attention. For examples, typical resolution ages, and how each pattern sounds in practice, see My 6-Year-Old Is Still Hard to Understand.
Why Does the Distinction Matter?
This is the important bit. Articulation errors and phonological processing errors need different therapy approaches — and getting the right one makes a real difference to how quickly your child progresses.
Therapy for Articulation Errors
For articulation difficulties, therapy focuses on the motor side of speech — teaching the child where to place their tongue, how to shape their lips, and how to produce the target sound accurately. We work on one sound at a time, building from single sounds to words, sentences, and conversation.
Therapy for Phonological Processing Errors
For phonological processing difficulties, therapy takes a language-based approach. Instead of drilling one sound in isolation, we target the underlying pattern. For example, if a child is fronting all their back sounds, we might work on helping them understand the difference between front and back sounds using minimal pairs — words that differ by just one sound, like "tea" and "key."
This approach can be very efficient, because when a child learns to eliminate a pattern, it often fixes multiple sounds at once. It's one of the most satisfying aspects of speech therapy — watching a child "unlock" a whole group of sounds once they've grasped the underlying pattern. In my experience, families are often surprised at how quickly a pattern-based approach can shift several sounds at once, once we've identified what the child's system is actually doing.
Getting the Assessment Right
This is exactly why a thorough speech sound assessment matters. Professor Barbara Dodd's classification system, which is widely used in Australian speech pathology practice, helps us distinguish between different types of speech sound difficulties — including articulation difficulties, phonological delay (where a child uses typical patterns but beyond the expected age), and phonological difficulties (where a child uses unusual or atypical patterns).
Dodd's framework gives us a clear way to identify what's going on and match the right therapy approach to your child's needs. Without this kind of careful classification, there's a risk of using a therapy approach that doesn't address the real underlying difficulty — which can mean slower progress and more frustration for everyone.
What Does a Speech Sound Assessment Involve?
When we assess your child's speech at Speaking Speech Pathology, we're looking at the full picture:
- Which sounds your child can and can't produce
- Whether there are patterns in the errors (phonological processes)
- Whether the errors are consistent or variable
- How well others understand your child (intelligibility)
- Whether there are any oral-motor factors affecting production
Speech Pathology Australia's clinical guidelines on speech sound assessment emphasise the importance of using standardised assessment tools alongside connected speech samples — because how a child produces sounds in a structured test can look quite different from how they speak in everyday conversation.
We also draw on the work of Sharynne McLeod and Elise Baker, whose research has been instrumental in guiding evidence-based assessment and intervention for children's speech sound difficulties. Their work highlights the importance of considering the whole child — their communication environment, their participation in daily life, and their own perspectives on their speech.
Whichever type it is — check hearing. Phonological or articulation, it's important to know how well a child is actually hearing the sounds around them. It's a piece of the puzzle worth never skipping, and an audiologist can sort it in a single appointment.
When Should You Seek Support?
As a general guide, consider getting a speech pathology assessment if:
- Your child is hard to understand for unfamiliar listeners by age 3
- They are frustrated when others can't understand them
- You notice patterns in the way they change sounds
- Their speech is not improving over time
- They are approaching school age and still have multiple sound errors
Early assessment means we can identify the type of speech sound difficulty, choose the right approach, and get started — which is always easier before the patterns become deeply established.
The Key Takeaway
Not all speech sound difficulties are the same. Articulation errors and phonological processing errors look different, work differently, and respond to different therapy approaches. A skilled assessment that distinguishes between the two is the foundation of effective speech therapy for your child.
Wondering whether your child's speech difficulties are articulation-based, phonological, or something else entirely? A thorough assessment is one common approach to find out — and it makes a real difference to getting the right therapy from the start. For families across Brisbane's south side and Logan, get in touch with Speaking Speech Pathology to book a speech sound assessment. Any actual clinical work — assessment, diagnosis, or therapy — happens through a proper consultation tailored to your child.
Ready for practical strategies? Read our companion article: How Speech Sound Errors Affect Reading and Learning | Brisbane Speech Pathologist
Alexandra Bouwmeester is a Senior Speech Pathologist (MSPA, CPSP) with over 14 years' experience helping families understand their child's speech sound profile and access the right evidence-based therapy. She offers mobile speech pathology to families across Brisbane's south side and Logan.
References
- Dodd, B. (2014). Differential diagnosis of pediatric speech sound disorders. Current Developmental Disorders Reports, 1(3), 189–196.
- McLeod, S., & Baker, E. (2017). Children's Speech: An Evidence-Based Approach to Assessment and Intervention. Pearson.
- Baker, E., & McLeod, S. (2011). Evidence-based practice for children with speech sound disorders: Part 1 — Narrative review. Language, Speech, and Hearing Services in Schools, 42(2), 102–139.
