Phonological Analysis in Private SLP Practice

In the previous blog post in this series I talked about the cost of obtaining a full kit of assessment materials for targeting your private practice at young children with speech sound disorders. Another important cost is the indirect time associated with each assessment. This is time well spent however because a proper analysis of an in-depth assessment will ensure that the treatment plan is effective. A good outcome requires not only time to analyze assessment results however: it requires expertise which brings us back to the topic of my first post in this series. I am aware that many practitioners and academics in our field are rather dismissive of “articulation”, thinking that it is easy to provide services in this area but in fact a considerable depth of expertise is required to fully understand children’s patterns of speech error, and more importantly, the underlying causes of those error patterns. I frequently tell my students about notable mistakes that occurred when I failed to make an in-depth analysis of a child’s speech. These errors resulted from over-confidence: often a speech sample appears to provide easy answers, the patterns appear to be obvious when they are not. Similarly, when SLPs are struggling to achieve progress with a child they will put out calls for help that assume the original problem description is accurate, e.g.,: “I am treating a four year who substitutes [k] for /t/ and I am not having much success. Can anyone help me?”

Their colleagues rush into help, despite the limited information, and assume that their own favourite procedures will be more effective. What if the description of the error pattern is faulty or a specific type of treatment approach is required to address the child’s underlying issues? Let’s examine the number of different possibilities, given this brief description.

  1. The child may actually substitute [t] for /k/ (SLPs describe these patterns backwards all the time as I have discussed before). Does the child also substitute [d] for /ɡ/ and [n] for /ŋ/? In this case, we have an ordinary velar fronting pattern. If there are other phonological processes and the child has good underlying phonological knowledge of the contrasts, the cycles approach is an excellent choice, keeping in mind the required intensity of treatment.
  2. Does the child have poor perceptual knowledge of the error contrasts? Regardless of whether the error is fronting or backing, it is essential to find out and this can be done using the SAILS tool (see Many children with a phonological disorder have problems with phonemic perception and will benefit from an input-oriented approach as described in our book (see also Rvachew & Brosseau-Lapre, 2015).
  3. Is the backing of velars context-specific? Camarata and Gandour (1984) describe an interesting case in which the child produced an alveolar stop before high vowels (e.g., tea, key→[ti]) but a velar stop before non-high vowels (e.g., cup, duck→[kʌp],[kʌk) and therefore the pattern provided evidence of an allophonic rule. A structured meta-phonological approach might be required to correct this kind of pattern.
  4. Another context-specific pattern involves assimilation. Perhaps the child produces the error only in those contexts that promote spreading of the Dorsal feature within a syllable (e.g., “chalk” → [kak]) or within a complex onset (e.g., “train” → [kweɪ]). [Good knowledge of multilinear phonology is required to understand and identify these patterns]. These errors are very specific to their contexts and cannot be corrected using procedures that are directed at a phonological process called “backing”. These assimilation errors usually self-correct as the child’s phonemic repertoire expands and stabilizes. The method of meaningful minimal pairs can be used to support the development of new phonemic contrasts. These methods are described in detail in our book.
  5. Is there evidence of an undifferentiated lingual gesture as described by Gibbon (1999)? In this case the alveolar and velar consonants might be produced with abnormal tongue movements such that the whole body of the tongue and the tongue blade rise to the palate and alveolar ridge to achieve closure of the vocal tract, followed by variable opening gestures. There may be other indications of articulatory difficulties such as distorted fricative sounds, reduced tongue strength, and/or slow single-syllable repetition rates. The results of the oral-motor examination and observation of the child’s tongue movements during speech will play a large role in differentiating an articulatory cause from a phonological or perceptual basis for the child’s speech error pattern. Clearly those children who have difficulty producing typical tongue movements during speech will need a therapeutic approach with an articulatory focus involving phonetic placement or visualization of the tongue.
  6. Are the apparent backing errors due to metathesis and other inconsistent word productions? For example, the child might be trying to say “helicopter” and produce [hɛkɪkɑpɚ], [hɛlɪpɑkɚ], and [hɛtɪlɑtɚ]. In this case there is no consistent pattern of substitutions related to the /t/ and the /k/ but a significant problem with the representation of the phoneme sequence for this word, or, with the planning of the phoneme sequence for this word prior to setting up the motor plan. This is referred to as inconsistent phonological disorder. It can be identified by administering the Word Inconsistency Assessment and by testing for deficits in phonological memory. The appropriate treatment is the Core Vocabulary Approach.
  7. Finally, backing errors are often considered to be a sign of Childhood Apraxia of Speech. However, this diagnosis would be appropriate only if there were other signs in the child’s speech such as segregation errors, distortion errors, and dysprosody. Furthermore, you would expect a slow three-syllable repetition rate in the presence of intact single-syllable repetition skills. The number of possible treatment approaches are too numerous to list here and would depend upon many aspects of the child’s profile. Often high-intensity practice of nonsense syllables forms part of the intervention however as described in the context of sensory-motor approaches for younger and older children in Chapter 10 of our book. See also RCTs by Murray, McCabe and Ballard (2015) and also Rvachew and Matthews (2019).

I have not explained how to conduct the detailed analysis that would reveal the different patterns that I have described here (again, our book lays out the procedures for multilinear analysis as well as the components of a deep assessment). The point is that designing a treatment program for a child with a speech disorder is not “easy”. It takes time and skill in every case. Planning for (and charging for) this time-consuming processing is an essential part of providing excellent service in a private practice. We can all feel proud of our ability to make these complex decisions. We must fight for the time, in public and private practice, to do this properly.

Phonology Assessment in SLP Private Practice

I am continuing with a series of blogs about private practice speech-language pathology. Fortunately many new clinicians can join an established practice and won’t have to think about these things. More frequently however young SLPs are setting up their own practice right out of school or very early on, in their home during their maternity leave for example. The focus of this blog is an aspect of setting up your practice that I am not seeing much advice about in other blogs (maybe I missed blogs about this, please write with links if I have). There other excellent blogs on setting up a private practice, for example 5 Key Steps to Start a Speech Therapy Private Practice ( ASHA also has a site the links to many key resources on the topics including ethics issues and quality indicators for your practice: Private Practice in Speech-Language Pathology ( I recommend these sources, but I am going to fill in a small but critical gap and that is the necessity of having the appropriate assessment materials on hand before you begin. And because you must obtain proper copyright to the materials or buy them (do not borrow them from your other employer!), I will provide some costing information.  In the last blog I talked about the importance of expertise and specializing in those clients you are most qualified to serve. Therefore, I will focus on speech sound disorders in children aged approximately 3 through 8 years.

The need to have assessment materials should be obvious. The practice guidelines world-wide indicate that your treatment goals and plans must be based on the results of a comprehensive assessment. Often times I see SLPs trying to select goals and treatment methods without having the results of a comprehensive assessment to guide their choices. How does this happen? There are so many reasons, almost too many to count but a few of them are unique to the private practice environment. Clients may not want to pay for the time it takes to assess when they are so desperate for treatment and their insurance may cover only 6 sessions. And the SLP may not want to pay for assessment materials when they are so expensive and observation can be valuable. Free observation is not a substitute for systematic assessment and analysis of the data in any circumstance. In the next blog I will demonstrate all the ways that superficial observations can be misinterpreted or at least differently interpreted. Even if the data is a detailed speech sample, a transcription and phonological analysis will be required. So which assessment tools are minimally required? Francoise and I developed a rubric for this, shown as Figure 5-1 in our DPD text and Figure 3-2 in our IntroSSD text. I will show the types of assessments in the table below, including those that are mandatory and those that are optional* and suggest options for each with free and commercial sources indicated.

ConstructPossible TestSource
Contextual factorsCase historyDPD text Publications :: Plural Publishing
Articulation accuracyDEAP Articulation TestDiagnostic Evaluation of Articulation and Phonology (DEAP) (
StimulabilityDEAP or informalInformal is fine
Oral-motor screenDEAP or other publishede.g., DPD has 3
Speech accuracy in continuous speechReference data for Percent Consonants Correct) Shriberg et al.Reproduced in DPD or see Austin & Shriberg (1997)
Hearing acuityHearing screeningFree apps: HearScreen — THE AUDIOLOGY PROJECT
Phonology*DEAP or hand scored from conversational sampleSee above or DPD
Word Inconsistency*DEAPSee above
IntelligibilityIntelligibility in Context ScaleOverview – Multilingual Children’s Speech (
Speech Perception*Speech-Production Perception Task or SAILSFree procedure in DPD or see
Phonological Awareness*Phonological Awareness Test (implicit)Free with norms in DPD
Nonword Repetition*Syllable Repetition TaskOverview – The Phonology Project – UW–Madison (
Language screene.g., QUILS (3 to 5 yrs) or SPELT (4 to 9 yrs) Or story retell with SALTLanguage Screening Tools – QUILS (
SALT Home Page (
Intelligence screen*Kaufman Brief Intelligence TestClinical Assessment Canada – English (

This list of required test materials looks lengthy but the ultimate cost is quite moderate. Instructions and normative data for the case history, the oral-peripheral examination, articulation and phonological analysis for toddlers through school age children (with normative expectations), speech perception testing and an implicit awareness test are all tucked inside the DPD text which can be obtained for $150.00. Measures of intelligibility, a hearing screener, and the syllable repetition task are available free on the internet. You should have a standardized measure of articulation and/or phonology. I like the DEAP because it is comprehensive with good diagnostic properties; it costs about $600 with test forms. You can measure expressive language abilities informally although it is time consuming to do so. For younger children the QUILS receptive language screener is only $100. Generally standardized tests are in the $300 to $600 range unfortunately.

You might question the value of the optional tests, especially the K-BIT. However, I strongly recommend having the Kaufman Brief Intelligence Test because it includes a receptive vocabulary test as the verbal IQ screen and a nonverbal IQ screen and often you need a little bit of extra information to justify referring children to a psychologist. I have struggled to achieve progress with quite a few preschoolers in my practice who turned out to have very significant but undiscovered cognitive delays. The K-BIT is sold by Pearson for about $500. For children younger than four a play skills assessment can be a good substitute.

So, not worrying about exchange rates and rounding around the edges, you can count on spending $1500 on assessment materials in your first year. You should count on spending that much every year in order to update your editions and add tests in areas not covered by this stripped down list. After you add your provincial and federal association fees and your malpractice and liability insurance you are still not paying very much to start charging people for your services. The real costs come with actually conducting and then scoring the tests, and in phonology, analyzing the data. However, that is the competence that your clients are paying you for. More about that in the next post.