Using randomized variable practice in the treatment of childhood apraxia of speech

Update on Identification and Treatment of Infants and Toddlers With Suspected Childhood Apraxia of Speech

PURPOSE

The purpose of this tutorial is to (a) provide an updated review of the literature pertaining to proposed early features of childhood apraxia of speech (CAS), (b) discuss the findings of recent treatment studies of infants and toddlers with suspected CAS (sCAS), and (c) present evidence-based strategies and tools that can be used for the identification of and intervention for infants and toddlers with sCAS or at high risk for the disorder.

METHOD

Since Davis and Velleman's (2000) seminal work on assessment and intervention in infants and toddlers with sCAS, limited research has guided clinicians in the complex task of identifying and treating early speech motor difficulties prior to a definitive diagnosis of CAS. Following the structure of Davis and Velleman, we explore the proposed early characteristics of CAS with reference to contemporary research. Next, we describe the limited treatment studies that have investigated intervention for infants and toddlers at risk of or suspected of having CAS. Finally, we present practical suggestions for integrating this knowledge into clinical practice.

CONCLUSIONS

Many of the originally proposed correlates of CAS in infants and toddlers now have research supporting their presence. However, questions remain about the developmental trajectory of the disorder. Although limited in number and restricted by lack of experimental control, emerging treatment studies can help guide clinicians in providing appropriate intervention to infants and toddlers with sCAS who need not wait for a definitive diagnosis to initiate intervention.

Dynamic Temporal and Tactile Cueing: Quantifying Speech Motor Changes and Individual Factors That Contribute to Treatment Gains in Childhood Apraxia of Speech

PURPOSE

Speech motor skill is refined over the course of practice, which is commonly reflected by increased accuracy and consistency. This research examined the relationship between auditory-perceptual ratings of word accuracy and measures of speech motor timing and variability at pre- and posttreatment in children with childhood apraxia of speech (CAS). Furthermore, the degree to which individual patterns of baseline probe word accuracy, receptive language, and cognition predicted response to treatment was explored.

METHOD

Probe data were collected from seven children with CAS (aged 2;5-5;0 [years;months]) who received 6 weeks of Dynamic Temporal and Tactile Cueing (DTTC) treatment. Using a multidimensional approach to measuring speech performance, auditory-perceptual (whole-word accuracy), acoustic (whole-word duration), and kinematic (jaw movement variability) analyses were conducted on probe words produced pre- and posttreatment. Standardized tests of receptive language and cognition were administered pretreatment.

RESULTS

There was a negative relationship between auditory-perceptual measures of word accuracy and movement variability. Higher word accuracy was associated with lower jaw movement variability following intervention. There was a strong relationship between word accuracy and word duration at baseline, which became less robust posttreatment. Furthermore, baseline word accuracy was the only child-specific factor to predict response to DTTC treatment.

CONCLUSIONS

Following a period of motor-based intervention, children with CAS appeared to refine speech motor control in conjunction with improvements in word accuracy. Those who demonstrated the poorest performance at treatment onset displayed the greatest degree of gains. Taken together, these results reflect a system-wide change following motor-based intervention.

Treatment for Childhood Apraxia of Speech: Past, Present, and Future

PURPOSE

The purposes of this review article were to provide an introduction to and "bird's-eye" overview of the current evidence base for treatment of childhood apraxia of speech (CAS), identify some gaps and trends in this rapidly growing literature, and formulate some future research directions, in order to advance the evidence base and clinical practice for children with CAS.

METHOD

Following a brief introduction outlining important concepts, a narrative review of the CAS treatment literature is provided, and trends and future directions are identified based on this review. The review is organized around four fundamental treatment research questions: (a) "Does Treatment X work?", (b) "Does Treatment X work better than Treatment Y?", (c) "For whom does Treatment X work?", and (d) "What does 'work' mean, anyway?"

RESULTS

A wide range of CAS treatments with varying degrees of evidence for efficacy exists. Research is beginning to emerge that compares different treatments and seeks to determine optimal treatment parameters. Few studies to date have explored child-level predictors of treatment response, and the evidence base currently is limited in scope with respect to populations and outcomes studied.

CONCLUSIONS

A growing evidence base supports the efficacy of a number of treatments for CAS. However, many important gaps in the literature were identified that warrant redoubled and sustained research attention. Research is beginning to emerge that addresses treatment optimization, comparison, candidacy, and outcomes. Suggestions for future research are offered, and the concept of a hypothesized pathway was applied to CAS to illustrate how components of an intervention can effect change in a clinical goal and can help guide development and refinement of treatments for children with CAS.

Dynamic Temporal and Tactile Cueing in Young Children With Childhood Apraxia of Speech: A Multiple Single-Case Design

PURPOSE

Childhood apraxia of speech (CAS) is a multivariate motor speech disorder that requires a motor-based intervention approach. There is limited treatment research on young children with CAS, reflecting a critical gap in the literature given that features of CAS are often in full expression early in development. Dynamic Temporal and Tactile Cueing (DTTC) is a treatment approach designed for children with severe CAS, yet the use of DTTC with children younger than 3 years of age has not been examined.

METHOD

A multiple single-case design was employed to examine the use of DTTC in seven children with CAS (aged 2.5-5 years) over the course of 6 weeks of intervention. Changes in word accuracy were measured in treated words from baseline to posttreatment and from baseline to maintenance (6 weeks posttreatment). Generalization of word accuracy changes to matched untreated words was also examined. A linear mixed-effects model was used to estimate the change in word accuracy for treated and untreated words across all children from baseline to posttreatment and to maintenance. A quasi-Poisson regression model was used to estimate mean change and calculate effect sizes for treated and untreated words.

RESULTS

Group-level analyses revealed significant changes in word accuracy for treated and untreated words at posttreatment and maintenance. At the child level, six of seven children displayed medium-to-large effect sizes where word accuracy increased in an average of 3.4/5 words across all children. Each child displayed some degree of generalization to untreated targets, specifically for words with the same syllable shape as the treated words.

CONCLUSIONS

These results demonstrate that DTTC can yield positive change in some young children with CAS. Key differences in each child's performance are highlighted.

The role of lag effect in distributed practice on learning novel vocabulary

PURPOSE

The purpose of the current study was to investigate the lag effects in two different versions of distributed practice on learning novel language vocabulary.

METHOD

Forty-four healthy monolingual English-speaking participants were randomly assigned to two versions of distributed practice. The two versions of distributed practice were created by altering the temporal lag between the practice sessions. Participants in both groups completed a similar practice regimen wherein they practiced 30 French occupations five times each for a total of 150 times. The pre/post-design employed in this experiment involved participants completing baseline, immediate, and delayed retention tests. The outcome measures included a comprehensive multiple-choice test and a written expression task.

RESULTS

The findings from the comprehensive and expressive tasks indicated that the learning performance of participants across both groups was better during the immediate retention test compared to the delayed retention test. With regard to the group, participants assigned to the condensed version of distributed practice demonstrated superior learning of the novel vocabulary over participants assigned to the extended version of distributed practice.

CONCLUSION

The findings indicate that an increased temporal lag between the practice sessions results in a "non-monotonic function," wherein the learning continues to improve until an optimal lag, after which the learning declines as the lag continues to increase. This line of research will have a substantive impact on service-delivery models in speech-language pathology.

A Pilot Randomized Control Trial of Motor-Based Treatments for Childhood Apraxia of Speech: Rapid Syllable Transition Treatment and Ultrasound Biofeedback

PURPOSE

Both Rapid Syllable Transition Treatment (ReST) and ultrasound biofeedback are effective approaches to treating childhood apraxia of speech (CAS). The purpose of the study was to compare outcomes from these two motor-based treatment approaches for school-age children with CAS.

METHOD

In a single site, single blind randomized control trial, 14 children with CAS ages 6-13 years were randomly assigned to 12 sessions over 6 weeks of either of ultrasound biofeedback treatment (with a speech motor chaining practice structure) or ReST. Treatment was delivered at The University of Sydney by students trained and supervised by certified speech-language pathologists. Transcriptions from blinded assessors were used to compare the two groups on speech sound accuracy (percent phonemes correct) and prosodic severity (lexical stress errors and syllable segregation) in untreated words and sentences at three time points: pretreatment, immediately posttreatment, and 1-month posttreatment (i.e., retention).

RESULTS

Both groups showed significant improvement on treated items indicating a treatment effect. At no time was there a difference between groups. Both groups showed a significant improvement in speech sound accuracy on untreated words and sentences from pre to post and neither group showed an improvement in prosody pre-post. Changes to speech sound accuracy were retained by both groups at 1-month follow-up. Significant improvement in prosodic accuracy was reported at the 1-month follow-up.

CONCLUSIONS

ReST and ultrasound biofeedback were equally effective. Either ReST or ultrasound biofeedback may be viable treatment options for school-age children with CAS.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.22114661.

A survey of the clinical management of childhood apraxia of speech in the United States and Canada

PURPOSE

Limited information is available about the current practices of generalist speech-language pathologists (SLPs) in relation to their management of childhood apraxia of speech (CAS). This study was designed to investigate four primary questions separately for the US and Canada; 1. What treatment approaches are used by SLP clinicians to treat CAS? 2. What treatment format and intensity are used to deliver CAS treatment? 3. What are the attitudes and perspectives of SLPs to evidence-based practice (EBP) as it pertains to CAS treatment? and 4. What are the perceived barriers to the implementation of EBP in CAS treatment?

METHOD

An online questionnaire was used to investigate the four primary research questions. The questionnaire was distributed online through social media, some state-based associations and through forums affiliated with national speech-language-hearing associations.

RESULTS

Most survey respondents reported frequently using an eclectic approach to treat CAS (US 85%; Canada 89%). Although no intervention emerged as the most preferred primary treatment for CAS, US-based clinicians more commonly reported using the Kaufman Speech to Language Protocol (K-SLP) (33%) and Dynamic, Temporal and Tactile Cueing (DTTC) (28%); while clinicians in Canada used PROMPT ® (31%). SLPs demonstrated a positive attitude towards EBP however, they identified a range of perceived barriers that impacted their implementation of EBP.

CONCLUSION

SLPs in the US and Canada frequently used an eclectic approach to treat CAS which is consistent with previous findings both in the CAS literature and the wider speech disorders literature. The more commonly used primary interventions were the K-SLP and DTTC (US); and PROMPT ® (Canada), with one of the strongest factors that influenced clinicians' choice of intervention being familiarity with the treatment approach. Face to face therapy was preferred by clinicians across both countries, with clinicians in the US providing therapy between 2-5 times per week, while those in Canada delivered therapy up to once per week. Clinicians identified a number of barriers to implementing evidence-based practice, among which, being time poor was most commonly selected across clinicians in both the US and Canada.

Performance in the accuracy task in children with Childhood Apraxia of Speech after an integrated intervention of literacy and motor skills

Difficult in literacy skills are often seen in children with Childhood Apraxia of Speech (CAS). This occurs because oral language has direct relationship with reading and writing learning. The purpose of this study was to evaluate the performance in the accuracy task of an integrated phonoarticulatory awareness, motor skills and literacy intervention of three children with CAS. Three boys between 5;3 and 5;8 years of age, with CAS, were offered 2 hours per week of therapy sessions based on literacy and motor skills. The children were assessed before and after therapy and at a maintenance assessment 1 month after the treatment ceased. The children improved on the accuracy task considering their deficits level. Improvement was maintained at the maintenance assessment. Therapy based on literacy considering phonoarticulatory awareness and motor skills can help children with CAS, but the severity of the children's communication problems must be taken into consideration.

Application of the Challenge Point Framework During Treatment of Speech Sound Disorders

Purpose The purpose of this article is to provide trial-by-trial practice performance data in relation to learning (outcome probe data) as collected from 18 treatment sessions provided to children with severe speech sound disorders. The data illustrate the practice-learning paradox: Specific, perfect practice performance is not required for speech production learning. Method We detailed how nine student speech-language pathologists (SSLPs) implemented and modified the motor learning practice conditions to reach a proposed challenge point during speech practice. Eleven participants diagnosed with a severe speech sound disorder received high-intensity speech therapy 3 times per week for 6 weeks. SSLPs implemented treatment procedures with the goal of achieving at least 100 practice trials while manipulating practice parameters to maintain practice at the challenge point. Specifically, child performance was monitored for accuracy in five-trial increments, and practice parameters were changed to increase functional task difficulty when the child's performance was high (four or five correct responses) or to decrease functional task difficulty when the child's performance was low (fewer than four correct responses). The practice stimulus, type and amount of feedback, structure of practice, or level of support might be changed to ensure practice at the challenge point. Results On average, the children achieved 102 practice trials per session at a level of 58% correct responses. Fast achievement of connected speech with the lowest amount of support was associated with high scores on generalization probes. Even with high levels of error during practice, the children improved percent consonants correct with maintenance of learning 3 months posttreatment. Conclusion The results of this study show that it may not be necessary to overpractice or maintain a high degree of performance accuracy during treatment sessions to achieve transfer and retention of speech production learning.

A Pilot Single-Case Experimental Design Study of Rapid Syllable Transition Treatment for Italian Children With Childhood Apraxia of Speech

Background The Rapid Syllable Transition (ReST) treatment is an effective intervention designed to address the planning and programming disorder found in childhood apraxia of speech. To date, no study has considered its use with children who speak languages other than English. Aim This pilot study aimed to examine the use of ReST treatment with Italian children. We hypothesized that the ReST approach would improve the overall accuracy of the targeted behaviors of lexical stress, smoothness, and phonemic accuracy, whereas phonemic and phonetic accuracy of untreated items would remain stable. Method Two monolingual Italian-speaking children with childhood apraxia of speech received therapy in 12 one-hour sessions, 2-3 times per week, using a single-case experimental design. The treatment procedures used in English were replicated in Italian with one change: In English, two stress patterns are treated. Italian commonly uses three stress patterns; therefore, the stimuli were modified accordingly. Accuracy of articulation, lexical stress, and smoothness were assessed at pretreatment and 1 day, 1 week, and 4 months posttreatment in treated and untreated pseudowords and in real words and sentences. Results Both children improved on treated pseudowords and real words with moderate effect sizes, but only one child generalized to untreated pseudowords. Maintenance of treatment results was observed in both participants. Articulation of control phonemes did not change. Conclusions ReST treatment in Italian is feasible, and a treatment effect was found, showing that its use may be valid in languages other than English. Further research is required. Supplemental Material https://doi.org/10.23641/asha.14348060.

How the Study of Speech Motor Control Can Inform Assessment and Intervention in Childhood Apraxia of Speech

Purpose

The study of speech motor control has led to great advancements in the current understanding of childhood apraxia of speech (CAS). There remains a significant need to bridge the gap between theory and practice to fully understand the clinical implications of past research.

Method

This review article reviews the speech motor control research in CAS and discusses how these works have offered key information about the underlying motor deficits (Grigos et al., 2015; Terband et al., 2019), the influence of structured practice on speech performance (Case & Grigos, 2016; Grigos & Case, 2018), and the role of task complexity (Case, 2019; Case & Grigos, 2016; Grigos & Case, 2018). We highlight salient points from this existing literature and clinical implications to the assessment and treatment of CAS.

Conclusion

The study of speech motor control has shed light on a number of key factors related to CAS. Even within perceptually accurate speech, children with CAS display differences in movement patterning and timing control. Assessment must aim to more directly tax speech motor skills to obtain a thorough and accurate illustration of production deficits. Intervention is challenged with the task of not only improving production accuracy but also facilitating more efficient motor planning and programming. Motor-based intervention that applies motor learning principles and introduces variability across motor, phonetic, and prosodic contexts is believed to achieve this goal, though research is needed to better understand changes in speech motor control with treatment.

Role of Massed Versus Distributed Practice in Learning Novel Foreign Language Utterances

The current study compared the role of massed versus distributed practice in learning novel foreign language utterances. Fifty healthy native English-speaking participants were randomly assigned to either massed or distributed practice groups. All participants practiced eight novel French utterances 25 times each for a total of 200 times, with the spacing of practice sessions differing between the two groups. Both the groups completed an immediate retention as well as a delayed retention test. Participants' learning was evaluated based on phonetic accuracy and naturalness of the French utterances. The findings revealed that participants involved in distributed practice demonstrated better learning over participants involved in massed practice. Future research should aim to extrapolate these findings in treating speech disorders.

Bang for Your Buck: A Single-Case Experimental Design Study of Practice Amount and Distribution in Treatment for Childhood Apraxia of Speech

Purpose The aim of this study was to examine 2 aspects of treatment intensity in treatment for childhood apraxia of speech (CAS): practice amount and practice distribution. Method Using an alternating-treatments single-subject design with multiple baselines, we compared high versus low amount of practice, and massed versus distributed practice, in 6 children with CAS. Conditions were manipulated in the context of integral stimulation treatment. Changes in perceptual accuracy, scored by blinded analysts, were quantified with effect sizes. Results Four children showed an advantage for high amount of practice, 1 showed an opposite effect, and 1 showed no condition difference. For distribution, 4 children showed a clear advantage for massed over distributed practice post treatment; 1 showed an opposite pattern, and 1 showed no clear difference. Follow-up revealed a similar pattern. All children demonstrated treatment effects (larger gains for treated than untreated items). Conclusions High practice amount and massed practice were associated with more robust speech motor learning in most children with CAS, compared to low amount and distributed practice, respectively. Variation in effects across children warrants further research to determine factors that predict optimal treatment conditions. Finally, this study adds to the evidence base supporting the efficacy of integral stimulation treatment for CAS. Supplemental Material https://doi.org/10.23641/asha.9630599.

Clinical management of childhood apraxia of speech: A survey of speech-language pathologists in Australia and New Zealand

Purpose: A number of studies have been published that have investigated the practices of speech-language pathologists in relation to speech sound disorder intervention; however, specific research about the treatment of childhood apraxia of speech is not available. This study aimed to describe the treatment approaches being used by speech-language pathologists, explore their perspectives of evidence-based practice and identify perceived barriers to implementing empirical research recommendations. Method: An online survey was distributed to speech-language pathologists in Australia and New Zealand. In total, 109 valid surveys were completed by participants who answered a series of multiple choice, yes/no, short answer and Likert-scaled questions. Result: Speech-language pathologists demonstrated a strong preference for eclectic interventions to treat childhood apraxia of speech. When asked to identify the primary treatment approach they used (whether as a stand-alone; or as the primary approach within an eclectic intervention), the most frequently used intervention was the Nuffield Dyspraxia Programme. Many speech-language pathologists reported valuing empirical research evidence, despite identifying a range of barriers that impact their ability to implement evidence-based practice in childhood apraxia of speech treatment. Conclusion: Although many speech-language pathologists use the Nuffield Dyspraxia Programme as their primary intervention, most clinicians use it as part of an eclectic/hybrid intervention. The effectiveness of eclectic interventions for childhood apraxia of speech has not been empirically evaluated.

Tutorial: Speech Motor Chaining Treatment for School-Age Children With Speech Sound Disorders

Purpose Operationalized treatments for school-age children with speech sound disorders may result in more replicable and evidence-based interventions. This tutorial describes Speech Motor Chaining (SMC) procedures, which are designed to build complex speech around core movements by incorporating several principles of motor learning. The procedures systematically manipulate factors such as feedback type and frequency, practice variability, and stimulus complexity based on the child's performance. Method The rationale and procedures for SMC are described. Examples are presented of how to design stimuli, deliver feedback, and adapt the approach. Free resources are provided to guide clinicians through implementation of the procedure. Data on fidelity of implementation and dose per session are presented. Clinical and research evidence is provided to illustrate likely outcomes with the procedure. Results SMC is a method that can result in successful acquisition of target speech patterns and generalization to untrained words. Most clinicians can implement the procedure with over 90% fidelity, and most children can achieve over 200 trials per session. Conclusion Clinicians and researchers can use or adapt the operationally defined SMC procedures to incorporate several principles of motor learning into treatment for school-age children with speech sound disorders. Supplemental Material https://osf.io/5jmf9/.

Interventions for childhood apraxia of speech

BACKGROUND

Childhood apraxia of speech (CAS) affects a child's ability to produce sounds and syllables precisely and consistently, and to produce words and sentences with accuracy and correct speech rhythm. It is a rare condition, affecting only 0.1% of the general population. Consensus has been reached that three core features have diagnostic validity: (1) inconsistent error production on both consonants and vowels across repeated productions of syllables or words; (2) lengthened and impaired coarticulatory transitions between sounds and syllables; and (3) inappropriate prosody (ASHA 2007). A deficit in motor programming or planning is thought to underlie the condition. This means that children know what they would like to say but there is a breakdown in the ability to programme or plan the fine and rapid movements required to accurately produce speech. Children with CAS may also have impairments in one or more of the following areas: non-speech oral motor function, dysarthria, language, phonological production impairment, phonemic awareness or metalinguistic skills and literacy, or combinations of these. High-quality evidence from randomised controlled trials (RCTs) is lacking on interventions for CAS.

OBJECTIVES

To assess the efficacy of interventions targeting speech and language in children and adolescents with CAS as delivered by speech and language pathologists/therapists.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, eight other databases and seven trial registers up to April 2017. We searched the reference lists of included reports and requested information on unpublished trials from authors of published studies and other experts as well as information groups in the areas of speech and language therapy/pathology and linguistics.

SELECTION CRITERIA

RCTs and quasi-RCTs of children aged 3 to 16 years with CAS diagnosed by a speech and language pathologist/therapist, grouped by treatment types.

DATA COLLECTION AND ANALYSIS

Two review authors (FL, AM) independently assessed titles and abstracts identified from the searches and obtained full-text reports of all potentially relevant articles and assessed these for eligibility. The same two authors extracted data and conducted the 'Risk of bias' and GRADE assessments. One review author (EM) tabulated findings from excluded observational studies (Table 1).

MAIN RESULTS

This review includes only one RCT, funded by the Australian Research Council; the University of Sydney International Development Fund; Douglas and Lola Douglas Scholarship on Child and Adolescent Health; Nadia Verrall Memorial Scholarship; and a James Kentley Memorial Fellowship. This study recruited 26 children aged 4 to 12 years, with mild to moderate CAS of unknown cause, and compared two interventions: the Nuffield Dyspraxia Programme-3 (NDP-3); and the Rapid Syllable Transitions Treatment (ReST). Children were allocated randomly to one of the two treatments. Treatments were delivered intensively in one-hour sessions, four days a week for three weeks, in a university clinic in Australia. Speech pathology students delivered the treatments in the English language. Outcomes were assessed before therapy, immediately after therapy, at one month and four months post-therapy. Our review looked at one-month post-therapy outcomes only.We judged all core outcome domains to be low risk of bias. We downgraded the quality of the evidence by one level to moderate due to imprecision, given that only one RCT was identified. Both the NDP-3 and ReST therapies demonstrated improvement at one month post-treatment. A number of cases in each cohort had recommenced usual treatment by their speech and language pathologist between one month and four months post-treatment (NDP-3: 9/13 participants; ReST: 9/13 participants). Hence, maintenance of treatment effects to four months post-treatment could not be analysed without significant potential bias, and thus this time point was not included for further analysis in this review.There is limited evidence that, when delivered intensively, both the NDP-3 and ReST may effect improvement in word accuracy in 4- to 12-year-old children with CAS, measured by the accuracy of production on treated and non-treated words, speech production consistency and the accuracy of connected speech. The study did not measure functional communication.

AUTHORS' CONCLUSIONS

There is limited evidence that, when delivered intensively, both the NDP-3 and ReST may effect improvement in word accuracy in 4- to 12-year-old children with CAS, measured by the accuracy of production on treated and non-treated words, speech production consistency and the accuracy of connected speech. The study did not measure functional communication. No formal analyses were conducted to compare NDP-3 and ReST by the original study authors, hence one treatment cannot be reliably advocated over the other. We are also unable to say whether either treatment is better than no treatment or treatment as usual. No evidence currently exists to support the effectiveness of other treatments for children aged 4 to 12 years with idiopathic CAS without other comorbid neurodevelopmental disorders. Further RCTs replicating this study would strengthen the evidence base. Similarly, further RCTs are needed of other interventions, in other age ranges and populations with CAS and with co-occurring disorders.

Model-Driven Treatment of Childhood Apraxia of Speech: Positive Effects of the Speech Motor Learning Approach

PURPOSE

The aim of the study was to propose the speech motor learning approach (Van der Merwe, 2011) as a treatment for childhood apraxia of speech and to determine if it will effect positive change in the ability of a 33-month-old child to produce untreated nonwords and words containing treated age-appropriate consonants (Set 1 sounds), untreated age-appropriate consonants (Set 2), and untreated age-inappropriate consonants (Set 3) and also to determine the nature and number of segmental speech errors before and after treatment.

METHOD

An A-B design with multiple target measures and follow-up was implemented to assess the effects of treatment of Set 1. Effect sizes for whole-word accuracy were determined, and two criterion lines were generated following the conservative dual criterion method. Speech errors were judged perceptually.

RESULTS

Conservative dual criterion analyses indicated no reliable treatment effect due to rising baseline scores. Effect sizes showed significant improvement in whole-word accuracy of untreated nonwords and real words containing age-appropriate treated sounds and real words containing age-appropriate untreated sounds. The number of errors for all three sound sets declined. Sound distortion was the most frequent error type.

CONCLUSIONS

Preliminary evidence suggests potentially positive treatment effects. However, rising baseline scores limit causal inference. Replication with more children of different ages is necessary.

SUPPLEMENTAL MATERIALS

https://doi.org/10.23641/asha.5596708.

Intensive Treatment for Persisting Rhotic Distortions: A Case Series

PURPOSE

The study explored changes in accuracy of American English rhotics as a result of an intensive 1-week therapy program for adolescents and young adults with residual speech sound errors that had not resolved with previous therapy.

METHOD

Four case reports are presented of individuals aged 13, 17, 21, and 22 years with residual /ɹ/ distortions. Each participant attended a 1-week intensive program consisting of pretreatment assessments, 14 hr of therapy, and posttreatment assessment. Treatment sessions included structured motor-based practice, ultrasound visual feedback of the tongue, and auditory speech perception training. To assess generalization, untreated words and sentences with rhotics were recorded before and after therapy; these were rated by listeners who were blind to when the recordings were taken.

RESULTS

All participants showed measurable and statistically significant improvement in speech sound accuracy. Averaged across the 4 participants, rhotic accuracy at the word level improved from 35% to 83%. At the sentence level, rhotic accuracy increased from 11% pretreatment to 66% posttreatment in 1 week.

CONCLUSION

The promise of an intensive treatment program that includes motor-based practice, biofeedback, and auditory perception training is illustrated by the case presentations in which substantial improvements in speech sound accuracy were observed.

SUPPLEMENTAL MATERIALS

https://doi.org/10.23641/asha.5561254.

Role of Constant, Random and Blocked Practice in an Electromyography-Based Oral Motor Learning Task

PURPOSE

The role of principles of motor learning (PMLs) in speech has received much attention in the past decade. Oral motor learning, however, has not received similar consideration. This study evaluated the role of three practice conditions in an oral motor tracking task.

METHOD

Forty-five healthy adult participants were randomly and equally assigned to one of three practice conditions (constant, blocked, and random) and participated in an electromyography-based task. The study consisted of four sessions, at one session a day for four consecutive days. The first three days sessions included a practice phase, with immediate visual feedback, and an immediate retention phase, without visual feedback. The fourth session did not include practice, but only delayed retention testing, lasting 10-15 minutes, without visual feedback.

RESULTS

Random group participants performed better than participants in constant and blocked practice conditions on all the four days. Constant group participants demonstrated superior learning over blocked group participants only on day 4.

CONCLUSION

Findings indicate that random practice facilitates oral motor learning, which is in line with limb/speech motor learning literature. Future research should systematically investigate the outcomes of random practice as a function of different oral and speech-based tasks.

Acquisition, retention, and generalization of rhotics with and without ultrasound visual feedback

PURPOSE

The purpose was to provide a preliminary within-participant comparison of speech therapy with and without exposure to ultrasound visual feedback for postvocalic rhotics (/r/- colored vowels). Effects of the two treatments on acquisition, retention, and generalization were explored. It was hypothesized that treatment with ultrasound would facilitate acquisition but hinder retention and generalization.

METHODS

A single subject randomized block design was replicated across four American English-speaking participants ages 7-9 years. Each participant was trained on postvocalic /r/. Each week for seven weeks, one session with ultrasound visual feedback and one session with no ultrasound were randomly ordered. A Training Probe and Generalization Probe were used to measure acquisition within each session as well as retention and generalization between two consecutive sessions. Graphical displays of the data, effect size calculation, and statistical results from a randomization test were used to analyze the results.

RESULTS

Two participants showed essentially no evidence of acquisition, retention or generalization of rhotics (<5%). Of the two who showed evidence of acquisition, one participant showed a significant advantage and large effect size for ultrasound sessions over no ultrasound sessions in acquisition of rhotics. However, no participants showed differences between treatment conditions in generalization or retention of rhotics.

CONCLUSION

For some children, acquisition may be facilitated by ultrasound visual feedback. Ultrasound visual feedback neither inhibited nor facilitated retention or generalization of rhotics. As a whole, the 14 treatment sessions (7 with ultrasound and 7 without) were effective for 2 of the 4 participants when comparing pre/post generalization scores. Future studies should evaluate the effectiveness of ultrasound visual feedback given a larger dose and differing age groups.