Articulation vs. Phonological Errors: Assessment and Treatment Approaches for Speech Sound Disorders
by Becky Whalen, Speech-language Pathologist and Pearson Assessment Consultant
As a speech-language pathologist, I’ve encountered countless students struggling with speech sound disorders (SSD), which can impact their ability to communicate and their self-confidence. Proper assessment and effective intervention for speech sound disorders (SSD) requires a deep understanding of the complexities involved — and the tools that can help diagnose and treat these specific issues.
Speech sound disorders encompass difficulties with speech sound production, and they are most commonly classified as articulation or phonological disorders. Distinguishing between the two can be tricky — even with extensive training and education — but it’s essential to diagnose them accurately in order to determine the most effective treatment strategies.
This backgrounder provides information that might be a helpful refresher for practitioners and a good resource for the families with whom they work.
Differentiating between speech sound disorders
Children with speech sound disorders may exhibit articulation errors, phonological errors or combined errors.
Articulation errors
Articulation errors are the most common type of speech sound disorder. They are motor-based problems — i.e., a child struggles to physically produce certain speech sounds correctly, such as an “S” in the case of a lisp. These errors are typically isolated to specific sounds rather than entire classes of sounds.
The main therapeutic focus for articulation errors is on improving the child’s motor control and articulatory placement. Common approaches include:
- Traditional articulation approach. This method uses techniques that focus on error sounds individually and therapy guides the child through a hierarchy of speech production tasks. The hierarchy begins with producing the sound in isolation and gradually progresses to syllables (like “sa” and “su”) then words (like “sad” or “soothe”) then sentences with the sound, and, finally, conversational speech. This approach is particularly effective for treating mild to moderate articulation errors, and it has a strong evidence base supporting its use.
- Stimulability approach. This approach is ideal for very young children (ages 2–4) who have limited phonetic inventories, such as “late talkers.” It involves engaging the child in activities that encourage them to imitate sounds, with the aim of expanding the sounds they can produce. Because the goal is to get them to make more sounds, this approach focuses on both correcting the sounds a child can already make and increasing their overall phonetic repertoire.
Phonological errors
Phonological errors are language-based, and they involve incorrect cognitive representations of speech sounds or phonological rules. These errors often affect sound classes, leading to patterns of errors that reduce the intelligibility of speech (i.e., how much we can understand what is being said).
The goal of therapy is to correct these underlying representations and processes. There are various approaches available. Common ones include:
- Cycles approach. This structured method is designed for children who have multiple phonological errors and severely unintelligible speech. It involves periods of auditory bombardment — where the child listens to repeated correct productions of target sounds — followed by production practice. For example, working on the “cuh” sound in words like “cold” or “cat.” The therapy occurs in cycles, where specific phonological patterns are targeted for a period and revisited later. This approach can help show a child how using a different sound within a word actually changes the meaning of the word.
- Minimal pairs approach. Minimal pairs therapy involves contrasting words that differ by only one phonological feature (such as “coat” vs. “goat”) to help the child recognize and produce sounds that differ by a single characteristic. This method is particularly effective for children who substitute one sound for another, as it helps them differentiate between similar sounds.
Combined errors
Some children may exhibit both articulation and phonological errors. This is what might be more expected in a severe case of speech sound disorder. For instance, a child with liquid gliding (such as substituting /w/ for /l/) may have trouble producing the sounds correctly and may also have unclear cognitive representations of the sounds. In such cases, a dual-treatment approach is required; the therapy must address both the motor-based and phonological aspects of the disorder.
Tools for accurate assessment of speech sound disorders
A thorough assessment is essential before selecting an effective treatment approach for speech sound disorders. Clinicians must determine whether the errors are primarily articulation-based, phonological or a combination of both. This distinction is crucial because it guides the choice of therapy strategies. Key tools in this assessment process can include the Goldman-Fristoe Test of Articulation (GFTA-3) and the Khan-Lewis Phonological Analysis (KLPA-3), along with speech sampling and phonological processing tasks.
Goldman-Fristoe Test of Articulation (GFTA)
The Goldman-Fristoe Test of Articulation (GFTA-3) is one of the most widely used assessments for evaluating articulation errors. It is used to identify which speech sounds a child has difficulty producing correctly. The GFTA-3 assesses a child’s ability to articulate individual speech sounds in different contexts — for example, at the word, sentence and conversational levels. These articulation errors typically involve problems with the physical production of sounds, such as difficulties coordinating the movements of the tongue, lips, teeth and other articulators, or with the substitution of one sound for another.
By pinpointing which specific sounds the child struggles with, the GFTA-3 provides detailed information on where the errors occur (such as initial, medial or final sound positions) and how they affect the child’s speech intelligibility,
Khan-Lewis Phonological Analysis (KLPA)
The Khan-Lewis Phonological Analysis (KLPA-3) complements the GFTA-3 by analyzing phonological processes, as discussed above. It takes the data collected from the GFTA-3 speech sample and evaluates whether the articulation errors are part of broader phonological patterns. This analysis provides insight into why the errors occur, whether they stem from difficulty producing certain sounds (articulation errors) or from a misunderstanding of sound rules (phonological errors).
How the GFTA and KLPA Work Together
By combining the results from both the GFTA-3 and KLPA-3, clinicians can obtain a detailed and complete picture of the child’s speech difficulties. The GFTA-3 helps identify which sounds are produced incorrectly, while the KLPA-3 explains why those errors are occurring by uncovering any underlying phonological processes. This holistic analysis is essential for designing a targeted treatment plan that addresses both the specific sound production errors and the phonological processes that may be affecting the child's overall speech intelligibility.
While manual analysis of the KLPA-3 can be done by SLPs — in fact, it's what’s generally taught in grad school — it can be very time consuming and challenging for clinicians to fully identify phonological patterns on the KLPA-3. Automatized analysis for the KLPA-3 can be done through two of Pearson’s digital platforms — Q-global and Q interactive — which streamlines the process remarkably.
Additional assessment tools
In addition to formal assessments like the GFTA-3 and KLPA-3, other evaluation processes may also be used to gather comprehensive data about the child’s speech:
- Speech sampling. Collecting spontaneous speech samples in natural settings allows clinicians to observe speech patterns that might not be captured during structured testing. This helps in understanding the child’s real-world speech difficulties and offers a better picture of how it’s impacting their ability to interact with their parents, teachers and peers.
- Phonological processing tasks. Assessing phonological processing in a child with a phonological disorder can help identify the specific difficulties the child has with sound recognition, manipulation and production, which are the core components of speech and language. Understanding these underlying challenges can guide the development of targeted interventions that focus on improving the child's phonemic awareness and sound system organization. Additionally, assessing phonological processing is important because it can help predict future difficulties with reading and spelling, as phonological awareness is closely linked to literacy development.
Accurate diagnosis is the key to effective intervention
The foundation of successful treatment of speech sound disorders lies in the accurate identification of whether the issue is articulation-based, phonological or both. Clinicians must gather thorough assessment data and remain flexible in their treatment approaches. A well-chosen therapy method — whether focused on motor production or phonological processing — can lead to significant improvements in a child’s speech clarity and overall communication abilities.
For more information and tools for supporting students with speech sound disorders, visit Pearson’s Speech & Language Assessments library today.