Intensive Treatment with Ultrasound Visual Feedback for Speech Sound Errors in Childhood Apraxia

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.

Unpacking the black box of voice therapy: A clinical application and revision of the Motor Learning Classification Framework (MLCF)

PURPOSE

Voice therapy is a complex behavioural intervention. Understanding its components is integral for continued advancement of voice therapy research, translation of evidence into the clinical setting and improved client care. The Motor Learning Classification Framework (MLCF) offers an excellent opportunity for increasing such knowledge, specifically in relation to identifying variables that affect motor learning (ML), an important mechanism hypothesised to bring about voice change during voice therapy. The MLCF has shown promising results in identifying speech-language pathologists' (SLPs) use of ML variables during experimentally controlled voice therapy contexts. The purpose of this study was to test the feasibility of applying the framework in the clinical context of everyday voice therapy practice.

METHOD

Data consisted of two video-recorded voice therapy sessions representing usual voice therapy care. Classification of ML variables used by SLPs during the recorded sessions was attempted based on the MLCF.

RESULT

Several problematic features of the framework were identified. Based on deliberations between the authors of the current paper, the MLCF was revised using an iterative process. This resulted in the construction of an updated version of the framework (MLCF-V2). The MLCF-V2 organises ML strategies into two broad categories: directly observable behaviours and learning processes. The framework incorporates greater consideration of theory and empirical evidence supporting motivational, attentional focus and subjective error estimation influences on ML. Several examples of each ML variable are included as well as an attempt to provide clearer classification instruction.

CONCLUSION

It is anticipated that the MLCF-V2 will provide a more useful and reliable classification for use in future investigations of SLPs' use of ML variables during usual voice therapy practice.

Feasibility of using ultrasound visual biofeedback to treat persistent speech sound disorders in children with cleft palate- a case series

The current study aimed to assess the effectiveness of incorporating ultrasound visual biofeedback (UVB) into a treatment programme addressing persistent speech sound disorders linked to cleft palate in children who have been unresponsive to traditional therapy approaches. Materials and Methods. A single-subject multiple baseline experiment was conducted with five children aged 6:5-13:5 over a period of 16 therapy sessions. Treatment focused on providing cues from real-time ultrasound images to assist children in modifying their tongue movements. Probe data were collected before, mid, and post-treatment to assess target consonant accuracy for 50 untreated words. The results of the statistical analysis suggested participants showed a significant increase in percent target consonant accuracy as a result of intervention using UVB. Although most of the participants exhibited progress in generalising learned phonemes to untreated words, some did not show improvement in gaining generalisation from treated phonemic contexts to those untreated ones. When traditional methods fail to yield significant progress, incorporating ultrasound biofeedback into the treatment programme emerges as a viable option to enhance sound accuracy in children with persistent speech sound disorders resulting from cleft palate.

Long-Term Outcomes for Individuals With Childhood Apraxia of Speech

PURPOSE

The study's primary aims were to describe the long-term speech outcomes for adolescents and young adults with a history of childhood apraxia of speech (CAS) and to examine the association of persistent speech sound errors with measures of literacy skills, phonological processing, motor speech production, and parent report of early motor difficulty.

METHOD

Data from a large longitudinal 25-year study were used to explore outcomes for 32 individuals with a history of CAS, ages 12;6 (years;months) to 25 years (M = 17.4, SD = 4.7). Persistent and nonpersistent groups were compared on decoding, phonological processing, multisyllabic word repetition, diadochokinetic rate, and parent report of motor involvement. Parametric (Welch's t tests) and nonparametric tests (Wilcoxon and Fisher exact tests) were used to identify differences between the groups' distributions. Developmental trajectories of speech production were plotted.

RESULTS

Outcomes for individuals with CAS are highly variable, with some demonstrating speech sound errors into adolescence and young adulthood. Speech sound errors were primarily on later developing sounds. Persistence was significantly associated with early motor difficulties. Difficulties with multisyllabic words, phonological processing, and literacy were often present regardless of persistence or nonpersistence of speech errors.

CONCLUSIONS

Children with CAS are at risk for persistent speech sound errors into adulthood. For children showing limited progress with more traditional speech therapy, alternative interventions should be explored. Individuals with persistent speech sound errors are more likely to have a history of early motor deficits. Regardless of persistence, participants with CAS demonstrated ongoing weaknesses in literacy, phonological processing skills, and complex speech production tasks.

The Reliability of Expert Diagnosis of Childhood Apraxia of Speech

PURPOSE

The current standard for clinical diagnosis of childhood apraxia of speech (CAS) is expert clinician judgment. The psychometric properties of this standard are not well understood; however, they are important for improving clinical diagnosis. The purpose of this study is to determine the extent to which experts agree on the clinical diagnosis of CAS using two cohorts of children with mixed speech sound disorders (SSDs).

METHOD

Speech samples of children with SSDs were obtained from previous and ongoing research from video recordings of children aged 3-8 years (n = 36) and audio recordings of children aged 8-17 years (n = 56). A total of 23 expert, English-speaking clinicians were recruited internationally. Three of these experts rated each speech sample to provide a description of the observed features and a diagnosis. Intrarater reliability was acceptable at 85% agreement.

RESULTS

Interrater reliability on the presence or absence of CAS among experts was poor both as a categorical diagnosis (κ = .187, 95% confidence interval [CI] [0.089, 0.286]) and on a continuous "likelihood of CAS" scale (0-100; intraclass correlation = .183, 95% CI [.037, .347]). Reliability was similar across the video-recorded and audio-only samples. There was greater agreement on other diagnoses (such as articulation disorder) than on the diagnosis of CAS, although these too did not meet the predetermined standard. Likelihood of CAS was greater in children who presented with more American Speech-Language-Hearing Association CAS consensus features.

CONCLUSIONS

Different expert raters had different thresholds for applying the diagnosis of CAS. If expert clinician judgment is to be used for diagnosis of CAS or other SSDs, further standardization and calibration is needed to increase interrater reliability. Diagnosis may require operationalized checklists or reliable measures that operate along a diagnostic continuum.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.23949105.

A Randomized Controlled Trial of Treatment Distribution and Biofeedback Effects on Speech Production in School-Age Children With Apraxia of Speech

PURPOSE

This study examines how ultrasound biofeedback and intensive treatment distribution affect speech sound generalization during an evidence-based treatment, Speech Motor Chaining, for children with persisting speech errors associated with childhood apraxia of speech (CAS).

METHOD

In a 2 × 2 factorial randomized controlled trial, children ages 9-17 years meeting CAS criteria were randomized to receive (a) a distributed treatment (20 sessions twice weekly over 10 weeks) or intensive treatment (20 hr in 5 weeks, with 10 hr in Week 1) and (b) treatment with or without biofeedback. Due to the COVID pandemic, some participants were randomized to distributed/intensive telepractice treatment only. The primary outcome was percent target sounds correct on untreated phrases (i.e., generalization) at the 10-week time point. More than 50,000 narrow phonetic transcriptions were analyzed.

RESULTS

Forty-eight participants completed treatment. Intensive treatment significantly increased generalization at all time points. The effect of biofeedback was significant at 5 weeks from the start of treatment but not significant at the primary 10-week time point. However, when comparing each group immediately after their 20 hr of treatment finished, generalization was significantly greater in intensive over distributed treatment and greater in ultrasound over no-ultrasound treatment (with a significant interaction favoring intensive treatment with ultrasound). Only the advantage of intensive treatment remained significant 5 weeks after groups finished treatment. There was no significant difference between face-to-face and telepractice modalities.

CONCLUSIONS

When the number of treatment hours is fixed, an intensive schedule of Speech Motor Chaining facilitated greater improvement than a distributed schedule. Ultrasound biofeedback initially accelerated learning, but the benefits may dissipate as treatment continues or after it ends.

Reproducible Speech Research With the Artificial Intelligence-Ready PERCEPT Corpora

BACKGROUND

Publicly available speech corpora facilitate reproducible research by providing open-access data for participants who have consented/assented to data sharing among different research teams. Such corpora can also support clinical education, including perceptual training and training in the use of speech analysis tools.

PURPOSE

In this research note, we introduce the PERCEPT (Perceptual Error Rating for the Clinical Evaluation of Phonetic Targets) corpora, PERCEPT-R (Rhotics) and PERCEPT-GFTA (Goldman-Fristoe Test of Articulation), which together contain over 36 hr of speech audio (> 125,000 syllable, word, and phrase utterances) from children, adolescents, and young adults aged 6-24 years with speech sound disorder (primarily residual speech sound disorders impacting /ɹ/) and age-matched peers. We highlight PhonBank as the repository for the corpora and demonstrate use of the associated speech analysis software, Phon, to query PERCEPT-R. A worked example of research with PERCEPT-R, suitable for clinical education and research training, is included as an appendix. Support for end users and information/descriptive statistics for future releases of the PERCEPT corpora can be found in a dedicated Slack channel. Finally, we discuss the potential for PERCEPT corpora to support the training of artificial intelligence clinical speech technology appropriate for use with children with speech sound disorders, the development of which has historically been constrained by the limited representation of either children or individuals with speech impairments in publicly available training corpora.

CONCLUSIONS

We demonstrate the use of PERCEPT corpora, PhonBank, and Phon for clinical training and research questions appropriate to child citation speech. Increased use of these tools has the potential to enhance reproducibility in the study of speech development and disorders.

Effects of Production Training With Ultrasound Biofeedback on Production and Perception of Second-Language English Tense-Lax Vowel Contrasts

PURPOSE

This study investigated the efficacy of ultrasound biofeedback compared to a traditional acoustic input-only method in the second-language (L2) production training of English tense-lax vowel contrasts (/i-ɪ/ and /e-ɛ/). The relationship between the degrees of production and perception learning was also examined to explore a potential L2 production-perception link.

METHOD

Using a pretest/training/posttest paradigm, two groups of native Mandarin speakers received three sessions of training, one with ultrasound and one with audio only. Perception performance was measured by accuracy in AX discrimination. Production performance was measured in terms of accuracy in repetition production and Euclidean distance between contrasting vowels.

RESULTS

Both groups showed significant improvements in posttest production and perception tasks. Additionally, the training benefits were retained 6 weeks after training. The two groups, however, did not differ significantly in training gains; nor was there a significant correlation between training-induced changes in perception and production performance.

CONCLUSIONS

The results indicate that ultrasound feedback is similarly effective as the audio-only training in improving the L2 production of English tense-lax contrasts and the benefits transferred to perception. The lack of correlation between production and perception gains suggests that the two modalities need to be separately trained to achieve desired L2 learning outcomes.

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.

Evaluation of a novel 8-channel RX coil for speech production MRI at 0.55 T

OBJECTIVE

Speech production MRI benefits from lower magnetic fields due to reduced off-resonance effects at air-tissue interfaces and from the use of dedicated receiver coils due to higher SNR and parallel imaging capability. Here we present a custom designed upper airway coil for ¹H imaging at 0.55 Tesla and evaluate its performance in comparison with a vendor-provided prototype 16-channel head/neck coil.

MATERIALS AND METHODS

Four adult volunteers were scanned with both custom speech and prototype head-neck coils. We evaluated SNR gains of each of the coils over eleven upper airway volumes-of-interest measured relative to the integrated body coil. We evaluated parallel imaging performance of both coils by computing g-factors for SENSE reconstruction of uniform and variable density Cartesian sampling schemes with R = 2, 3, and 4.

RESULTS

The dedicated coil shows approximately 3.5-fold SNR efficiency compared to the head-neck coil. For R = 2 and 3, both uniform and variable density samplings have g-factor values below 1.1 in the upper airway region. For R = 4, g-factor values are higher for both trajectories.

DISCUSSION

The dedicated coil configuration allows for a significant SNR gain over the head-neck coil in the articulators. This, along with favorable g values, makes the coil useful in speech production MRI.

Clinicians' Perspectives of Treatment for Lateralization Errors: A Quantitative and Qualitative Study

PURPOSE

This mixed-methods study aimed to obtain information regarding speech-language pathologists' (SLPs) perspectives about treatment of lateralization errors (LEs), challenges to implementing evidence-based LE treatment practice, and the sources SLPs' use to find evidence to treat LEs. This information can assist our understanding of ways to facilitate the uptake of evidence-based practice into the everyday treatment of clients with this disorder.

METHOD

A convergent parallel mixed-methods design was used to collect data from SLPs (N = 214) using 24 questions from an online survey distributed through electronic mailing lists and Speech and Hearing State Associations. Quantitative data were analyzed using frequencies and averages; themes and subthemes of qualitative data were analyzed using a content analysis approach with no a priori codes. Quantitative and qualitative results were compared and integrated.

RESULTS

Participants believed that LEs required individualized treatment before the age of 5 years, were largely caused by structural and neuromuscular factors, and required an understanding of orofacial and dental structure and function. Challenges to implementing LE treatment included a lack of skills and knowledge specific to LEs, competing demands on clinicians' time and resources, and a research-practice gap. Sources of evidence frequently used to obtain information about LE treatment were colleagues, trainings, workshops, and American Speech-Language-Hearing Association journals.

CONCLUSIONS

Clinicians believe that LE treatment is challenging and requires skill training. Future research in LEs will need to consider the real-world decisions clinicians must make when treating this disorder as well as clinicians' everyday constraints and challenges.

A Tool for Differential Diagnosis of Childhood Apraxia of Speech and Dysarthria in Children: A Tutorial

PURPOSE

While there has been mounting research centered on the diagnosis of childhood apraxia of speech (CAS), little has focused on differentiating CAS from pediatric dysarthria. Because CAS and dysarthria share overlapping speech symptoms and some children have both motor speech disorders, differential diagnosis can be challenging. There is a need for clinical tools that facilitate assessment of both CAS and dysarthria symptoms in children. The goals of this tutorial are to (a) determine confidence levels of clinicians in differentially diagnosing dysarthria and CAS and (b) provide a systematic procedure for differentiating CAS and pediatric dysarthria in children.

METHOD

Evidence related to differential diagnosis of CAS and dysarthria is reviewed. Next, a web-based survey of 359 pediatric speech-language pathologists is used to determine clinical confidence levels in diagnosing CAS and dysarthria. Finally, a checklist of pediatric auditory-perceptual motor speech features is presented along with a procedure to identify CAS and dysarthria in children with suspected motor speech impairments. Case studies illustrate application of this protocol, and treatment implications for complex cases are discussed.

RESULTS

The majority (60%) of clinician respondents reported low or no confidence in diagnosing dysarthria in children, and 40% reported they tend not to make this diagnosis as a result. Going forward, clinicians can use the feature checklist and protocol in this tutorial to support the differential diagnosis of CAS and dysarthria in clinical practice.

CONCLUSIONS

Incorporating this diagnostic protocol into clinical practice should help increase confidence and accuracy in diagnosing motor speech disorders in children. Future research should test the sensitivity and specificity of this protocol in a large sample of children with varying speech sound disorders. Graduate programs and continuing education trainings should provide opportunities to practice rating speech features for children with dysarthria and CAS.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19709146.

Computer-assisted challenge point intervention for residual speech errors

Purpose

This preliminary case series investigated the effects of biofeedback intervention for residual rhotic errors delivered within a modified challenge point framework. In the challenge point framework, practice difficulty is adaptively adjusted with the goal of enhancing generalization learning. This study more specifically evaluated the feasibility of a computer-mediated implementation of challenge point treatment for rhotic errors using a custom open-source software, the Challenge Point Program (CPP).

Method

Participants were five native English speakers, ages 7;3-15;5, who had established but not generalized correct rhotic production in previous treatment; overall treatment duration was flexible. Treatment incorporated either electropalatographic or visual-acoustic biofeedback and was structured by challenge point principles implemented using the CPP software.

Results

Participants were highly variable in the magnitude of generalization gains attained. However, the median overall effect size was 4.24, suggesting that participants' response in treatment tended to exceed the minimum value considered clinically significant.

Conclusions

These findings provide preliminary evidence that computer-mediated implementation of the challenge point framework can be effective in producing generalization in some participants.

Effects of Practice Variability on Second-Language Speech Production Training

BACKGROUND

Mastering the phonetics of a second language (L2) involves a component of speech-motor skill, and it has been suggested that L2 learners aiming to achieve a more native-like pronunciation could benefit from practice structured in accordance with the principles of motor learning.

PARTICIPANTS AND METHODS

This study investigated the influence one such principle, high versus low variability in practice, has on speech-motor learning for Korean adults seeking to acquire native-like production of English rhotics. Practice incorporated a commercially available intraoral placement device ("R Buddy," Speech Buddies Inc.). In a single-subject across-behaviors design, 8 participants were pseudorandomly assigned to practice rhotic targets in a low-variability (single word) or high-variability (multiple words) practice condition.

RESULTS

The hypothesized advantage for high-variability over low-variability practice was observed in the short-term time frame. However, long-term learning was limited in nature for both conditions.

CONCLUSION

These results suggest that future research should incorporate high-variability practice while identifying additional manipulations to maximize the magnitude of long-term generalization learning.

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.

Differences Between School-Aged Children with Apraxia of Speech and Other Speech Sound Disorders on Multisyllable Repetition

PURPOSE

To evaluate whether features of childhood apraxia of speech identified in previous literature could be replicated in a sample of school-age children.

METHOD

A literature review was conducted to identify candidate speech features that have been previously considered when differentiating childhood apraxia of speech from other types of speech sound disorders. The candidate features recoverable from blinded transcriptions of multisyllable word repetitions (MSWR) were applied to a cohort of 61 children, aged 7-17, previously classified as having childhood apraxia of speech (n=21) or non-CAS Speech Sound Disorder (SSD, n=40).

RESULTS

One hundred and ninety-four features had been explored in previous literature to assess their ability to differentiate CAS from other SSDs. Fifteen perceptual features were selected from this list to be applied to performance on the MSWR. In this sample, children with CAS differed from children with SSD on the prevalence of voicing changes, percent of structurally correct words, correct lexical stress, and syllable deletions within a speech corpus derived from the MSWR task.

CONCLUSION

Although previous literature points to numerous features as differentiating CAS from other SSDs, only a portion of those features were replicated in this sample of school-age children. Features of CAS that affect segmental accuracy, prosody and word structure may be likely to persist into late childhood and early adolescence.

Testing hypotheses about the underlying deficit of apraxia of speech through computational neural modelling with the DIVA model

Purpose: A recent behavioural experiment featuring a noise masking paradigm suggests that Apraxia of Speech (AOS) reflects a disruption of feedforward control, whereas feedback control is spared and plays a more prominent role in achieving and maintaining segmental contrasts. The present study set out to validate the interpretation of AOS as a possible feedforward impairment using computational neural modelling with the DIVA (Directions Into Velocities of Articulators) model.Method: In a series of computational simulations with the DIVA model featuring a noise-masking paradigm mimicking the behavioural experiment, we investigated the effect of a feedforward, feedback, feedforward + feedback, and an upper motor neuron dysarthria impairment on average vowel spacing and dispersion in the production of six/bVt/speech targets.Result: The simulation results indicate that the output of the model with the simulated feedforward deficit resembled the group findings for the human speakers with AOS best.Conclusion: These results provide support to the interpretation of the human observations, corroborating the notion that AOS can be conceptualised as a deficit in feedforward control.

Tongue Part Movement Trajectories for /r/ Using Ultrasound

Purpose

Because it shows the movement of different parts of the tongue in real time, ultrasound biofeedback therapy is a promising technology for speech research and remediation. One limitation is the difficulty of interpreting real-time ultrasound images of tongue motion. Our image processing system, TonguePART, tracks the tongue surface and allows for the acquisition of quantitative tongue part trajectories.

Method

TonguePART automatically identifies the tongue contour based on ultrasound image brightness and tracks motion of the tongue root, dorsum, and blade in real time. We present tongue part trajectory data from 2 children with residual sound errors on /r/ and 2 children with typical speech, focusing on /r/ (International Phonetic Alphabet ɹ) in the phonetic context /ɑr/. We compared the tongue trajectories to magnetic resonance images of sustained vowel /ɑ/ and /r/.

Results

Measured trajectories show larger overall displacement and greater differentiation of tongue part movements for children with typical speech during the production of /ɑr/, compared to children with residual speech sound disorders.

Conclusion

TonguePART is a fast, reliable method of tracking articulatory movement of tongue parts for syllables such as /ɑr/. It is extensible to other sounds and phonetic contexts. By tracking tongue parts, clinical researchers can investigate lingual coordination. TonguePART is suitable for real-time data collection and biofeedback. Ultrasound biofeedback therapy users may make more progress using simplified biofeedback of tongue movement.

Speech Sound Disorders in Children: An Articulatory Phonology Perspective

Speech Sound Disorders (SSDs) is a generic term used to describe a range of difficulties producing speech sounds in children (McLeod and Baker, 2017). The foundations of clinical assessment, classification and intervention for children with SSD have been heavily influenced by psycholinguistic theory and procedures, which largely posit a firm boundary between phonological processes and phonetics/articulation (Shriberg, 2010). Thus, in many current SSD classification systems the complex relationships between the etiology (distal), processing deficits (proximal) and the behavioral levels (speech symptoms) is under-specified (Terband et al., 2019a). It is critical to understand the complex interactions between these levels as they have implications for differential diagnosis and treatment planning (Terband et al., 2019a). There have been some theoretical attempts made towards understanding these interactions (e.g., McAllister Byun and Tessier, 2016) and characterizing speech patterns in children either solely as the product of speech motor performance limitations or purely as a consequence of phonological/grammatical competence has been challenged (Inkelas and Rose, 2007; McAllister Byun, 2012). In the present paper, we intend to reconcile the phonetic-phonology dichotomy and discuss the interconnectedness between these levels and the nature of SSDs using an alternative perspective based on the notion of an articulatory "gesture" within the broader concepts of the Articulatory Phonology model (AP; Browman and Goldstein, 1992). The articulatory "gesture" serves as a unit of phonological contrast and characterization of the resulting articulatory movements (Browman and Goldstein, 1992; van Lieshout and Goldstein, 2008). We present evidence supporting the notion of articulatory gestures at the level of speech production and as reflected in control processes in the brain and discuss how an articulatory "gesture"-based approach can account for articulatory behaviors in typical and disordered speech production (van Lieshout, 2004; Pouplier and van Lieshout, 2016). Specifically, we discuss how the AP model can provide an explanatory framework for understanding SSDs in children. Although other theories may be able to provide alternate explanations for some of the issues we will discuss, the AP framework in our view generates a unique scope that covers linguistic (phonology) and motor processes in a unified manner.

Individual predictors of response to biofeedback training for second-language production

While recent research suggests that visual biofeedback can facilitate speech production training in clinical populations and second language (L2) learners, individual learners' responsiveness to biofeedback is highly variable. This study investigated the hypothesis that the type of biofeedback provided, visual-acoustic versus ultrasound, could interact with individuals' acuity in auditory and somatosensory domains. Specifically, it was hypothesized that learners with lower acuity in a sensory domain would show greater learning in response to biofeedback targeting that domain. Production variability and phonological awareness were also investigated as predictors. Sixty female native speakers of English received 30 min of training, randomly assigned to feature visual-acoustic or ultrasound biofeedback, for each of two Mandarin vowels. On average, participants showed a moderate magnitude of improvement (decrease in Euclidean distance from a native-speaker target) across both vowels and biofeedback conditions. The hypothesis of an interaction between sensory acuity and biofeedback type was not supported, but phonological awareness and production variability were predictive of learning gains, consistent with previous research. Specifically, high phonological awareness and low production variability post-training were associated with better outcomes, although these effects were mediated by vowel target. This line of research could have implications for personalized learning in both L2 pedagogy and clinical practice.

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.

Systematic review of ultrasound visual biofeedback in intervention for speech sound disorders

BACKGROUND

As cost and access barriers to ultrasound technology have decreased, interest in using ultrasound visual biofeedback (U-VBF) as a tool for remediating speech sound disorders (SSD) has increased. A growing body of research has investigated U-VBF in intervention for developmental SSD; however, diversity in study design, participant characteristics, clinical methods and outcomes complicate the interpretation of this literature. Thus, there is a need for a synthesis and review of the evidence base for using U-VBF in intervention for SSD.

AIMS

To synthesise and evaluate the research evidence for U-VBF in intervention for developmental SSD.

METHODS

A systematic review was conducted. Eight electronic databases were searched for peer-reviewed articles published before 2018. Details about study design, participants, intervention procedures, service delivery, intervention intensity and outcomes were extracted from each study that met the inclusion criteria. The included studies were rated using both a critical appraisal tool and for their reporting of intervention detail.

MAIN CONTRIBUTIONS

Twenty-eight papers, comprising 29 studies, met the inclusion criteria. The most common research design was single-case experimental design (44.8% of studies). The studies included between one and 13 participants (mean = 4.1) who had a mean age of approximately 11 years (range = 4;0-27 years). Within the research evidence, U-VBF intervention was typically provided as part of, or as an adjunct to, other articulatory-based therapy approaches. A range of lingual sounds were targeted in intervention, with 80.6% of participants across all reviewed studies receiving intervention targeting rhotics. Outcomes following therapy were generally positive with the majority of studies reporting that U-VBF facilitated acquisition of targets, with effect sizes ranging from no effect to a large effect. Difficulties with generalisation were observed for some participants. Most studies (79.3%) were categorised as efficacy rather than effectiveness studies and represented lower levels of evidence. Overall, the reviewed studies scored more highly on measures of external validity than internal validity.

CONCLUSIONS

The evidence base for U-VBF is developing; however, most studies used small sample sizes and lower strength designs. Current evidence indicates that U-VBF may be an effective adjunct to intervention for some individuals whose speech errors persist despite previous intervention. The results of this systematic review underscore the need for more high-quality and large-scale research exploring the use of this intervention in both controlled and community contexts.

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/.

Enabling New Articulatory Gestures in Children With Persistent Speech Sound Disorders Using Ultrasound Visual Biofeedback

Purpose This study evaluated ultrasound visual biofeedback treatment for teaching new articulations to children with a wide variety of speech sound disorders. It was hypothesized that motor-based intervention incorporating ultrasound would lead to rapid acquisition of a range of target lingual gestures with generalization to untreated words. Method Twenty children aged 6-15 years with a range of mild to severe speech disorders affecting a variety of lingual targets enrolled in a case series with replication. Of these, 15 children completed the intervention. All of the children presented with a variety of errors. We therefore employed a target selection strategy to treat the most frequent lingual error. These individual speech targets were treated using ultrasound visual biofeedback as part of ten to twelve 1-hr intervention sessions. The primary outcome measure was percentage of target segments correct in untreated wordlists. Results Six children were treated for velar fronting; 3 children, for postalveolar fronting; 2 children, for backing alveolars to pharyngeal or glottal place; 1 child, for debuccalization (production of all onsets as [h]); 1 child, for vowel merger; and 2 children, for lateralized sibilants. Ten achieved the new articulation in the 1st or 2nd session of intervention, despite no children being readily stimulable for their target articulation before intervention. In terms of generalization, effect sizes for percentage of target segments correct ranged from no effect (5 children), small effect (1 child), medium effect (4 children), and large effect (5 children). Conclusions Ultrasound visual biofeedback can be used to treat a wide range of lingual errors in children with various speech sound disorders, from mild to severe. Visual feedback may be useful for establishing new articulations; however, generalization is more variable.

Estimates of the prevalence of speech and motor speech disorders in adolescents with Down syndrome

Although there is substantial rationale for a motor component in the speech of persons with Down syndrome (DS), there presently are no published estimates of the prevalence of subtypes of motor speech disorders in DS. The goal of this research is to provide initial estimates of the prevalence of types of speech disorders and motor speech disorders in adolescents with DS. Conversational speech samples from a convenience sample of 45 adolescents with DS, ages 10 to 20 years old, were analysed using perceptual and acoustic methods and measures in the Speech Disorders Classification System (SDCS). The SDCS cross-classified participants into five mutually exclusive speech classifications and five mutually exclusive motor speech classifications. For participants meeting criteria for Childhood Dysarthria or for Childhood Dysarthria concurrent with Childhood Apraxia of Speech, the SDCS provided information on participants' percentile status on five subtypes of dysarthria. A total of 97.8% of participants met SDCS criteria for Speech Disorders and 97.8% met criteria for Motor Speech Disorders, including Childhood Dysarthria (37.8%), Speech Motor Delay (26.7%), Childhood Dysarthria and Childhood Apraxia of Speech (22.2%), and Childhood Apraxia of Speech (11.1%). Ataxia was the most prevalent dysarthria subtype. Nearly all participants with DS in the present sample had some type of speech and motor speech disorder, with implications for theory, assessment, prediction, and treatment. Specific to treatment, the present findings are interpreted as support for motor speech disorders as a primary explanatory construct to guide the selection and sequencing of treatment targets for persons with DS. Abbreviations: CAS: Childhood Apraxia of Speech; CD: Childhood Dysarthria; DS: Down syndrome; NSA: Normal(ized) Speech Acquisition; PSD: Persistent Speech Delay; PSE: Persistent Speech Errors; SD: Speech Delay; SDCS: Speech Disorders Classification System; SE: Speech Errors; SMD: Speech Motor Delay.

Treatment for Residual Rhotic Errors With High- and Low-Frequency Ultrasound Visual Feedback: A Single-Case Experimental Design

PURPOSE

The aim of this study was to explore how the frequency with which ultrasound visual feedback (UVF) is provided during speech therapy affects speech sound learning.

METHOD

Twelve children with residual speech errors affecting /ɹ/ participated in a multiple-baseline across-subjects design with 2 treatment conditions. One condition featured 8 hr of high-frequency UVF (HF; feedback on 89% of trials), whereas the other included 8 hr of lower-frequency UVF (LF; 44% of trials). The order of treatment conditions was counterbalanced across participants. All participants were treated on vocalic /ɹ/. Progress was tracked by measuring generalization on /ɹ/ in untreated words.

RESULTS

After the 1st treatment phase, participants who received the HF condition outperformed those who received LF. At the end of the 2-phase treatment, within-participant comparisons showed variability across individual outcomes in both HF and LF conditions. However, a group level analysis of this small sample suggested that participants whose treatment order was HF-LF made larger gains than those whose treatment order was LF-HF.

CONCLUSIONS

The order HF-LF may represent a preferred order for UVF in speech therapy. This is consistent with empirical work and theoretical arguments suggesting that visual feedback may be particularly beneficial in the early stages of acquiring new speech targets.

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.

Do Participants Report Any Undesired Effects in Ultrasound Speech Therapy?

Purpose

Ultrasound visual feedback of the tongue is increasingly used as a component of speech therapy in clinical research and practice. The purpose is to offer a preliminary summary of the nature of participant-reported undesired effects related to ultrasound visual feedback.

Method

Sixty-two participants across 3 sites (mean age = 11.9 years) and 38 parents responded to a 2-item verbal questionnaire following 14-16 hr of treatment regarding any aspects of the treatment they did not like. Responses were thematically categorized.

Results

The 62 participants provided 65 distinct responses, which were categorized as follows: 31% no concerns, 40% gel-related (e.g., cold, sticky), 21% positioning of the probe (e.g., uncomfortable, annoying), 3% chin hurting (qualified as being minor in nature), and 5% other (i.e., unrelated to the use of the ultrasound). Responses from all parents suggested no concerns about the use of ultrasound; however, 8% expressed concerns unrelated to ultrasound use (e.g., fatigue).

Conclusion

These data inform clinicians and researchers about participant's experience and highlight the type of comments most likely to be encountered with ultrasound in speech therapy. Although the reported adverse effects can be considered minor, they should be weighed against the potential benefits of visual feedback in treatment.

The Effect of Hand Gesture Cues Within the Treatment of /r/ for a College-Aged Adult With Persisting Childhood Apraxia of Speech

PURPOSE

Despite the widespread use of hand movements as visual and kinesthetic cues to facilitate accurate speech produced by individuals with speech sound disorders (SSDs), no experimental investigation of gestural cues that mimic that spatiotemporal parameters of speech sounds (e.g., holding fingers and thumb together and "popping" them to cue /p/) currently exists. The purpose of this study was to examine the effectiveness of manual mimicry cues within a multisensory intervention of persisting childhood apraxia of speech (CAS).

METHOD

A single-subject ABAB withdrawal design was implemented to assess the accuracy of vowel + /r/ combinations produced by a 21-year-old woman with persisting CAS. The effect of manual mimicry gestures paired with multisensory therapy consisting of verbal instructions and visual modeling was assessed via clinician and naïve listener ratings of target sound accuracy.

RESULTS

According to the perceptual ratings of the treating clinician and 28 naïve listeners, the participant demonstrated improved speech sound accuracy as a function of the manual mimicry/multisensory therapy.

CONCLUSIONS

These data offer preliminary support for the incorporation of gestural cues in therapy for CAS and other SSDs. The need for continued research on the interaction of speech and manual movements for individuals with SSDs is discussed.

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.