Random versus blocked practice in treatment for childhood apraxia of speech

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.

Assessment of Childhood Apraxia of Speech: A Review/Tutorial of Objective Measurement Techniques

Background With respect to the clinical criteria for diagnosing childhood apraxia of speech (commonly defined as a disorder of speech motor planning and/or programming), research has made important progress in recent years. Three segmental and suprasegmental speech characteristics-error inconsistency, lengthened and disrupted coarticulation, and inappropriate prosody-have gained wide acceptance in the literature for purposes of participant selection. However, little research has sought to empirically test the diagnostic validity of these features. One major obstacle to such empirical study is the fact that none of these features is stated in operationalized terms. Purpose This tutorial provides a structured overview of perceptual, acoustic, and articulatory measurement procedures that have been used or could be used to operationalize and assess these 3 core characteristics. Methodological details are reviewed for each procedure, along with a short overview of research results reported in the literature. Conclusion The 3 types of measurement procedures should be seen as complementary. Some characteristics are better suited to be described at the perceptual level (especially phonemic errors and prosody), others at the acoustic level (especially phonetic distortions, coarticulation, and prosody), and still others at the kinematic level (especially coarticulation, stability, and gestural coordination). The type of data collected determines, to a large extent, the interpretation that can be given regarding the underlying deficit. Comprehensive studies are needed that include more than 1 diagnostic feature and more than 1 type of measurement procedure.

Remediating Residual Rhotic Errors With Traditional and Ultrasound-Enhanced Treatment: A Single-Case Experimental Study

Purpose The aim of the study was to examine how ultrasound visual feedback (UVF) treatment impacts speech sound learning in children with residual speech errors affecting /ɹ/. Method Twelve children, ages 9-14 years, received treatment for vocalic /ɹ/ errors in a multiple-baseline across-subjects design comparing 8 sessions of UVF treatment and 8 sessions of traditional (no-biofeedback) treatment. All participants were exposed to both treatment conditions, with order counterbalanced across participants. To monitor progress, naïve listeners rated the accuracy of vocalic /ɹ/ in untreated words. Results After the first 8 sessions, children who received UVF were judged to produce more accurate vocalic /ɹ/ than those who received traditional treatment. After the second 8 sessions, within-participant comparisons revealed individual variation in treatment response. However, group-level comparisons revealed greater accuracy in children whose treatment order was UVF followed by traditional treatment versus children who received the reverse treatment order. Conclusion On average, 8 sessions of UVF were more effective than 8 sessions of traditional treatment for remediating vocalic /ɹ/ errors. Better outcomes were also observed when UVF was provided in the early rather than later stages of learning. However, there remains a significant individual variation in response to UVF and traditional treatment, and larger group-level studies are needed. Supplemental Material https://doi.org/10.23641/asha.8206640.

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.

Intelligibility Enhancement Assessment and Intervention: a single-case experimental design with two multilingual university students

Speech-language pathologists (SLPs) may be approached by multilingual speakers wishing to improve their intelligibility in English. Intelligibility is an essential element of spoken language proficiency and is particularly important for multilingual international students given their need to express complex ideas in an additional language. Intelligibility Enhancement aims to improve the intelligibility and acceptability of consonants, vowels and prosody with multilingual speakers who are learning to speak English. This study aimed to describe the Intelligibility Enhancement Assessment and Intervention Protocols and determine whether the intervention changed multilingual university students' English intelligibility. A multiple-baseline single-case experimental design was applied with direct inter-subject replication across two female participants whose home languages were Vietnamese and Putonghua (Mandarin). English intelligibility was assessed at multiple intervals pre, post and during intervention. The intervention protocol consisted of 11 weekly 1-h sessions with an SLP targeting English consonants, vowels and prosody. Following intervention, both participants displayed increased performance across most measures. For example, the Vietnamese participant's percentage of consonants correct (PCC) increased from 62.5% to 85.0% in probe keywords. Effect sizes, when comparing baseline and withdrawal phases, were 5.5 for PCC, 4.6 for final consonants, 2.3 for consonant clusters and 1.6 for syllables indicating improvements in all variables measured. Her speech rate reduced, word stress increased in accuracy and she perceived less difficulty communicating in English. These promising results suggest further testing of the Intelligibility Enhancement Protocols is warranted to determine effectiveness as an intervention for multilingual speakers.

Selected rare paediatric communication neurological disorders

The purpose of this review is to discuss rare neurological disorders with respect to communication difficulties typical of children. Firstly, communication disorders with special focus on rare communication neurological disorders are discussed. Secondly, on the basis of literature review, the authors explore clinical studies on the most typical rare children's communication neurological disorders. Thirdly, on the basis of the findings from the clinical studies, they set a few recommendations for their medical therapies and management. The methodology was based on the literature review of research studies exploring the research issue. The findings show that the intervention strategies appear to have positive effects on the improvement of speech and language production among children suffering from Landau-Kleffner syndrome and childhood apraxia of speech. Nevertheless, randomized control trials are needed in order to accelerate and facilitate an early and relevant diagnosis and treatment management. In addition, a multidisciplinary approach seems to be the most appropriate for the accurate diagnosis and comprehensive treatment.

A shift of treatment approach in speech language pathology services for children with speech sound disorders - a single case study of an intense intervention based on non-linear phonology and motor-learning principles

Even though there are documented benefits of direct intensive intervention for children with speech sound disorders (SSDs), the intensity given at Swedish Speech Language Pathology services rarely exceeds once a week. Also, indirect therapy approaches are commonly employed. The purpose of the present case study was to investigate the effects of an intensive specialist therapy, based on non-linear phonological analysis and motor learning principles. The participant was a boy aged 4:10 years with severe SSD, who previously had received indirect therapy from age 3 with, very limited results. A single subject ABA design was used. At baseline, whole word match was 0%, Word shape CV match was 39% and PCC was 22, 7%. He had no multisyllabic words, no consonant clusters and no established coronals. Intervention was given 4 days weekly for 3 weeks in two periods with a 7-week intervening break and a post therapy assessments. Therapy was focused on establishing multisyllabic words, iambic stress pattern, clusters and coronals with the principle of using already established elements for targeting new elements. At post therapy assessment, whole word match was 39%, word shape CV match was 71% and PCC 69.1%. Multisyllabic words (86%), coronals (82%) and word initial clusters (80%) were established. Without being targeted, back vowels were also present and segment timing improved. The strong treatment effects of this study demonstrate that at least severe cases of SSD require the clinical knowledge and skills that only a SLP can provide and that frequent direct therapy is both beneficial and needed.

Language Skill Mediates the Relationship Between Language Load and Articulatory Variability in Children With Language and Speech Sound Disorders

PURPOSE

The aim of the study was to investigate the relationship between language load and articulatory variability in children with language and speech sound disorders, including childhood apraxia of speech.

METHOD

Forty-six children, ages 48-92 months, participated in the current study, including children with speech sound disorder, developmental language disorder (aka specific language impairment), childhood apraxia of speech, and typical development. Children imitated (low language load task) then retrieved (high language load task) agent + action phrases. Articulatory variability was quantified using speech kinematics. We assessed language status and speech status (typical vs. impaired) in relation to articulatory variability.

RESULTS

All children showed increased articulatory variability in the retrieval task compared with the imitation task. However, only children with language impairment showed a disproportionate increase in articulatory variability in the retrieval task relative to peers with typical language skills.

CONCLUSION

Higher-level language processes affect lower-level speech motor control processes, and this relationship appears to be more strongly mediated by language than speech skill.

Frequencies in Perception and Production Differentially Affect Child Speech

PURPOSE

Frequent sounds and frequent words are both acquired at an earlier age and are produced by children more accurately. Recent research suggests that frequency is not always a facilitative concept, however. Interactions between input frequency in perception and practice frequency in production may limit or inhibit growth. In this study, we consider how a range of input frequencies affect production accuracy and referent identification.

METHOD

Thirty-three typically developing 3- and 4-year-olds participated in a novel word-learning task. In the initial test block, participants heard nonwords 1, 3, 6, or 10 times-produced either by a single talker or by multiple talkers-and then produced them immediately. In a posttest, participants heard all nonwords just once and then produced them. Referent identification was probed in between the test and posttest.

RESULTS

Production accuracy was most clearly facilitated by an input frequency of 3 during the test block. Input frequency interacted with production practice, and the facilitative effect of input frequency did not carry over to the posttest. Talker variability did not affect accuracy, regardless of input frequency. The referent identification results did not favor talker variability or a particular input frequency value, but participants were able to learn the words at better than chance levels.

CONCLUSIONS

The results confirm that the input can be facilitative, but input frequency and production practice interact in ways that limit input-based learning, and more input is not always better. Future research on this interaction may allow clinicians to optimize various types of frequency commonly used during therapy.

Statistical considerations for crowdsourced perceptual ratings of human speech productions

Crowdsourcing has become a major tool for scholarly research since its introduction to the academic sphere in 2008. However, unlike in traditional laboratory settings, it is nearly impossible to control the conditions under which workers on crowdsourcing platforms complete tasks. In the study of communication disorders, crowdsourcing has provided a novel solution to the collection of perceptual ratings of human speech production. Such ratings allow researchers to gauge whether a treatment yields meaningful change in how human listeners' perceive disordered speech. This paper will explore some statistical considerations of crowdsourced data with specific focus on collecting perceptual ratings of human speech productions. Random effects models are applied to crowdsourced perceptual ratings collected in both a continuous and binary fashion. A simulation study is conducted to test the reliability of the proposed models under differing numbers of workers and tasks. Finally, this methodology is applied to a data set from the study of communication disorders.

Treating Speech Movement Hypokinesia in Parkinson's Disease: Does Movement Size Matter?

Purpose

This study evaluates the effects of a novel speech therapy program that uses a verbal cue and gamified augmented visual feedback regarding tongue movements to address articulatory hypokinesia during speech in individuals with Parkinson's disease (PD).

Method

Five participants with PD participated in an ABA single-subject design study. The treatment aimed to increase tongue movement size using a combination of a verbal cue and augmented visual feedback and was conducted in 10 45-min sessions over 5 weeks. The presence of visual feedback was manipulated during treatment. Articulatory working space of the tongue was the primary outcome measure and was examined during treatment and in cued and uncued sentences pre- and posttreatment. Changes in speech intelligibility in response to a verbal cue pre- and posttreatment were also examined.

Results

During treatment, 4/5 participants showed a beneficial effect of visual feedback on tongue articulatory working space. At the end of the treatment, they used larger tongue movements when cued, relative to their pretreatment performance. None of the participants, however, generalized the effect to the uncued sentences. Speech intelligibility of cued sentences was judged as superior posttreatment only in a single participant.

Conclusions

This study demonstrated that using an augmented visual feedback approach is beneficial, beyond a verbal cue alone, in addressing articulatory hypokinesia in individuals with PD. An optimal degree of articulatory expansion might, however, be required to elicit a speech intelligibility benefit.

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.

Effect of motor-based speech intervention on articulatory placement in the treatment of a posterior nasal fricative: a preliminary MRI study on a single subject

BACKGROUND

Posterior nasal fricatives are a learned compensatory articulation error and commonly substituted for oral fricatives. Treatment of such articulation errors requires the modification or teaching of skilled movements. A motor-based approach is designed to teach the complex motor skill movement sequences required in the production of sounds. Although motor learning research is well established, little has been done to determine how the approach changes the underlying physiology of articulatory movements. While the underlying anatomical configuration of the posterior nasal fricative has been described, no studies have quantified anatomic and physiological changes pre- and post-treatment.

AIMS

To use magnetic resonance imaging (MRI) to visualize and quantify the results of motor-based speech-intervention approach on articulatory placement for the treatment of the posterior nasal fricative.

METHODS & PROCEDURES

A 6-year-old male with a history of ear infections and posterior nasal fricative substitution for /s/ underwent six 1-h sessions of a motor-based treatment approach over the course of 2 weeks. Pre- and post-treatment evaluation included perceptual and instrumental assessment of speech and resonance. Perceptual resonance was rated by two speech-language therapists and articulation was assessed at the single-word level. Instrumental assessment included the See-Scape, Nasometer II and MRI during the sustained phonation of /s/. Amira v5.6 Visualization and Volume modelling software used the midsagittal and oblique coronal plane to measure dimensions of the articulatory anatomy.

OUTCOMES & RESULTS

Interrater reliability was assessed using a Pearson product moment correlation (α = .05) and ranged from r = .91 to .95. Intra-rater reliability was assessed using the intra-class correlation coefficient (.976) demonstrating a high degree of reliability with a 95% confidence interval. Articulation improved from 0% accuracy for /s/ in isolation at baseline to 100% for /s/ at the word level and 95% accuracy during conversational speech by session 6. Post-treatment results from this study revealed a greater shortening of the levator veli palatini (levator) muscle length during articulatory movements, more pronounced velar knee and dimple, decreased velar thickness, increased velar length and altered tongue position.

CONCLUSIONS & IMPLICATIONS

This study demonstrated the use of pre- and post-treatment imaging methodology to quantify articulatory changes following an intensive motor-based treatment approach. MRI demonstrated quantifiable changes in articulatory placement. Individuals who exhibit non-developmental and phoneme-specific articulation errors, such as the posterior nasal fricative, may be excellent candidates for short-term, intensive and frequent speech therapy sessions to remediate the production of the posterior nasal fricative.

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.

The Impact of Expiratory Muscle Strength Training on Speech Breathing in Individuals With Parkinson's Disease: A Preliminary Study

PURPOSE

The purpose of this study was to examine the impact of expiratory muscle strength training on speech breathing and functional speech outcomes in individuals with Parkinson's disease (PD).

METHOD

Twelve individuals with PD were seen once a week for 8 weeks: 4 pretraining (baseline) sessions followed by a 4-week training period. Posttraining data were collected at the end of the 4th week of training. Maximum expiratory pressure, an indicator of expiratory muscle strength, and lung volume at speech initiation were the primary outcome measures. Secondary outcomes included lung volume at speech termination, lung volume excursion, utterance length, and vocal intensity. Data were collected during a spontaneous speech sample. Individual effect sizes > 1 were considered significant.

RESULTS

Maximum expiratory pressure increased in a majority of participants after training. Training resulted in 2 main respiratory patterns: increasing or decreasing lung volume initiation. Lung volume termination and excursion, utterance length, and vocal loudness were not consistently altered by training.

CONCLUSIONS

Preliminary evidence suggests that the direct physiologic intervention of the respiratory system via expiratory muscle strength training improves speech breathing in individuals with PD, with participants using more typical lung volumes for speech following treatment.

A Clear Speech Approach to Accent Management

PURPOSE

A 5-session twice-weekly clear speech protocol with daily home practice was developed to enable Spanish-accented speakers of English to code-switch for increased listener ease of understanding. This study provides preliminary data to test the hypothesis that this protocol results in increased ease of understanding for native English listeners, not in decreased talker accentedness.

METHOD

Using a single-case experimental design, 6 adult native Spanish speakers with English proficiency participated in the protocol. Ease of understanding and accentedness were probed at least 5 times pretraining, at each training session, and once per week for 5 weeks posttraining. Thirty native English-speaking listeners assessed the probes using 7-point scales for each measure.

RESULTS

Ease of understanding improved for all participants (mean improvement = 3.5 points; effect size range = 6.98 to 15.33). Accentedness improved for 4 of 6 participants (mean improvement = 2.3 points; effect size range = 4.04 to 10.48). At the outset, most participants expressed concern that this approach would highlight speech errors. Upon follow-up, all participants reported confidence in using the approach and found it helpful in daily communication.

CONCLUSIONS

Further research should explore the effects of this protocol on intelligibility and acoustic metrics and their relationship to ease of understanding and accentedness.

Efficacy of Electropalatography for Treating Misarticulation of /r/

PURPOSE

The purpose of the present study was to document the efficacy of electropalatography (EPG) for the treatment of rhotic errors in school-age children. Despite a growing body of literature using EPG for the treatment of speech sound errors, there is little systematic evidence about the relative efficacy of EPG for rhotic errors.

METHOD

Participants were 5 English-speaking children aged 6;10 to 9;10, who produced /r/ at the word level with < 30% accuracy but otherwise showed typical speech, language, and hearing abilities. Therapy was delivered in twice-weekly 30-min sessions for 8 weeks.

RESULTS

Four out of 5 participants were successful in achieving perceptually and acoustically accurate /r/ productions during within-treatment trials. Two participants demonstrated generalization of /r/ productions to nontreated targets, per blinded listener ratings.

CONCLUSIONS

The present findings support the hypothesis that EPG can improve production accuracy in some children with rhotic errors. However, the utility of EPG is likely to remain variable across individuals. For rhotics, EPG training emphasizes one possible tongue configuration consistent with accurate rhotic production (lateral tongue contact). Although some speakers respond well to this cue, the narrow focus may limit lingual exploration of other acceptable tongue shapes known to facilitate rhotic productions.

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.

Effects of Blocked and Random Practice Schedule on Outcomes of Sound Production Treatment for Acquired Apraxia of Speech: Results of a Group Investigation

PURPOSE

The purpose of this investigation was to compare the effects of schedule of practice (i.e., blocked vs. random) on outcomes of Sound Production Treatment (SPT; Wambaugh, Kalinyak-Fliszar, West, & Doyle, 1998) for speakers with chronic acquired apraxia of speech and aphasia.

METHOD

A combination of group and single-case experimental designs was used. Twenty participants each received SPT administered with randomized stimuli presentation (SPT-R) and SPT applied with blocked stimuli presentation (SPT-B). Treatment effects were examined with respect to accuracy of articulation as measured in treated and untreated experimental words produced during probes.

RESULTS

All participants demonstrated improved articulation of treated items with both practice schedules. Effect sizes were calculated to estimate magnitude of change for treated and untreated items by treatment condition. No significant differences were found for SPT-R and SPT-B relative to effect size. Percent change over the highest baseline performance was also calculated to provide a clinically relevant indication of improvement. Change scores associated with SPT-R were significantly higher than those for SPT-B for treated items but not untreated items.

CONCLUSION

SPT can result in improved articulation regardless of schedule of practice. However, SPT-R may result in greater gains for treated items.

SUPPLEMENTAL MATERIALS

https://doi.org/10.23641/asha.5116831.

Efficacy of Visual-Acoustic Biofeedback Intervention for Residual Rhotic Errors: A Single-Subject Randomization Study

PURPOSE

This study documented the efficacy of visual-acoustic biofeedback intervention for residual rhotic errors, relative to a comparison condition involving traditional articulatory treatment. All participants received both treatments in a single-subject experimental design featuring alternating treatments with blocked randomization of sessions to treatment conditions.

METHOD

Seven child and adolescent participants received 20 half-hour sessions of individual treatment over 10 weeks. Within each week, sessions were randomly assigned to feature traditional or biofeedback intervention. Perceptual accuracy of rhotic production was assessed in a blinded, randomized fashion. Each participant's response to the combined treatment package was evaluated by using effect sizes and visual inspection. Differences in the magnitude of response to traditional versus biofeedback intervention were measured with individual randomization tests.

RESULTS

Four of 7 participants demonstrated a clinically meaningful response to the combined treatment package. Three of 7 participants showed a statistically significant difference between treatment conditions. In all 3 cases, the magnitude of within-session gains associated with biofeedback exceeded the gains associated with traditional treatment.

CONCLUSIONS

These results suggest that the inclusion of visual-acoustic biofeedback can enhance the efficacy of intervention for some individuals with residual rhotic errors. Further research is needed to understand which participants represent better or poorer candidates for biofeedback treatment.

Efficacious Treatment of Children With Childhood Apraxia of Speech According to the International Classification of Functioning, Disability and Health

There is increasing evidence for treatment approaches designed for children with childhood apraxia of speech (CAS). Despite this, no treatment has conclusive evidence to date. The CAS population is heterogeneous, with children presenting with varying symptom profiles, severity levels, and comorbidities. Consequently, treatment planning for children with CAS represents a clinical challenge. To assist clinicians in providing optimal care, this paper uses the International Classification of Functioning, Disability and Health (ICF) as a framework for identifying the body structures and functions, activities, and personal/environmental factors that should be considered when working with children with CAS. Evidence-based interventions are described and resources outlined to help guide the treatment planning process.

An exploratory study of the influence of load and practice on segmental and articulatory variability in children with speech sound disorders

This exploratory treatment study used phonetic transcription and speech kinematics to examine changes in segmental and articulatory variability. Nine children, ages 4 to 8 years old, served as participants, including two with childhood apraxia of speech (CAS), five with speech sound disorder (SSD) and two who were typically developing. Children practised producing agent + action phrases in an imitation task (low linguistic load) and a retrieval task (high linguistic load) over five sessions. In the imitation task in session one, both participants with CAS showed high degrees of segmental and articulatory variability. After five sessions, imitation practice resulted in increased articulatory variability for five participants. Retrieval practice resulted in decreased articulatory variability in three participants with SSD. These results suggest that short-term speech production practice in rote imitation disrupts articulatory control in children with and without CAS. In contrast, tasks that require linguistic processing may scaffold learning for children with SSD but not CAS.

A systematic review of treatment intensity in speech disorders

PURPOSE

Treatment intensity (sometimes referred to as "practice amount") has been well-investigated in learning non-speech tasks, but its role in treating speech disorders has not been largely analysed. This study reviewed the literature regarding treatment intensity in speech disorders.

METHOD

A systematic search was conducted in four databases using appropriate search terms. Seven articles from a total of 580 met the inclusion criteria. The speech disorders investigated included speech sound disorders, dysarthria, acquired apraxia of speech and childhood apraxia of speech. All seven studies were evaluated for their methodological quality, research phase and evidence level.

RESULT

Evidence level of reviewed studies ranged from moderate to strong. With regard to the research phase, only one study was considered to be phase III research, which corresponds to the controlled trial phase. The remaining studies were considered to be phase II research, which corresponds to the phase where magnitude of therapeutic effect is assessed. Results suggested that higher treatment intensity was favourable over lower treatment intensity of specific treatment technique(s) for treating childhood apraxia of speech and speech sound (phonological) disorders.

CONCLUSION

Future research should incorporate randomised-controlled designs to establish optimal treatment intensity that is specific to each of the speech disorders.

Articulatory Control in Childhood Apraxia of Speech in a Novel Word-Learning Task

PURPOSE

Articulatory control and speech production accuracy were examined in children with childhood apraxia of speech (CAS) and typically developing (TD) controls within a novel word-learning task to better understand the influence of planning and programming deficits in the production of unfamiliar words.

METHOD

Participants included 16 children between the ages of 5 and 6 years (8 CAS, 8 TD). Short- and long-term changes in lip and jaw movement, consonant and vowel accuracy, and token-to-token consistency were measured for 2 novel words that differed in articulatory complexity.

RESULTS

Children with CAS displayed short- and long-term changes in consonant accuracy and consistency. Lip and jaw movements did not change over time. Jaw movement duration was longer in children with CAS than in TD controls. Movement stability differed between low- and high-complexity words in both groups.

CONCLUSIONS

Children with CAS displayed a learning effect for consonant accuracy and consistency. Lack of change in movement stability may indicate that children with CAS require additional practice to demonstrate changes in speech motor control, even within production of novel word targets with greater consonant and vowel accuracy and consistency. The longer movement duration observed in children with CAS is believed to give children additional time to plan and program movements within a novel skill.

Differential Effects of Visual-Acoustic Biofeedback Intervention for Residual Speech Errors

Recent evidence suggests that the incorporation of visual biofeedback technologies may enhance response to treatment in individuals with residual speech errors. However, there is a need for controlled research systematically comparing biofeedback versus non-biofeedback intervention approaches. This study implemented a single-subject experimental design with a crossover component to investigate the relative efficacy of visual-acoustic biofeedback and traditional articulatory treatment for residual rhotic errors. Eleven child/adolescent participants received ten sessions of visual-acoustic biofeedback and 10 sessions of traditional treatment, with the order of biofeedback and traditional phases counterbalanced across participants. Probe measures eliciting untreated rhotic words were administered in at least three sessions prior to the start of treatment (baseline), between the two treatment phases (midpoint), and after treatment ended (maintenance), as well as before and after each treatment session. Perceptual accuracy of rhotic production was assessed by outside listeners in a blinded, randomized fashion. Results were analyzed using a combination of visual inspection of treatment trajectories, individual effect sizes, and logistic mixed-effects regression. Effect sizes and visual inspection revealed that participants could be divided into categories of strong responders (n = 4), mixed/moderate responders (n = 3), and non-responders (n = 4). Individual results did not reveal a reliable pattern of stronger performance in biofeedback versus traditional blocks, or vice versa. Moreover, biofeedback versus traditional treatment was not a significant predictor of accuracy in the logistic mixed-effects model examining all within-treatment word probes. However, the interaction between treatment condition and treatment order was significant: biofeedback was more effective than traditional treatment in the first phase of treatment, and traditional treatment was more effective than biofeedback in the second phase. This is consistent with existing theory and data suggesting that detailed knowledge of performance feedback is most effective in the early stages of motor learning. Further research is needed to confirm that an initial phase of biofeedback has a facilitative effect, and to determine the optimal duration of biofeedback treatment. In addition, there is a strong need for correlational studies to examine which individuals with residual speech errors are most likely to respond to treatment.

Is There an Interaction between Task Complexity and Practice Variability in Speech-Motor learning?

BACKGROUND

Prior studies have investigated the influence of principles of motor learning (PMLs) on speech-motor learning. However, the interactive effect of different PMLs on speech-motor learning remains unknown.

PURPOSE

This study is aimed at investigating the interaction of 2 PMLs, that is, practice variability and task complexity and their influence on speech-motor learning.

METHOD

Forty healthy individuals (aged 18-30 years) were randomly and equally allocated to 2 groups where they had to either practice a simple (simple group) or a complex phrase (complex group). Two levels of practice variability (constant and variable) were considered in training participants in simple and complex groups. Participants practiced 50 practice trials of either complex or simple phrase during the first 2 days. At the end of training on each day, participants produced 10 trials of the phrase they practiced without feedback. On the third day, participants returned for a delayed retention test. The participant utterances on all the 3 days were recorded for later analysis.

RESULTS

Data analysis revealed that there was no major effect of practice condition, and there was no interaction of task complexity and practice condition. However, there was an interaction between data collection points and complexity.

CONCLUSION

The findings suggest that irrespective of the complexity of the to-be-learned speech task, there is no preponderance of variable over constant practice, which contradicts the findings of the non-speech-motor learning literature.

Direction of attentional focus in biofeedback treatment for /r/ misarticulation

BACKGROUND

Maintaining an external direction of focus during practice is reported to facilitate acquisition of non-speech motor skills, but it is not known whether these findings also apply to treatment for speech errors. This question has particular relevance for treatment incorporating visual biofeedback, where clinician cueing can direct the learner's attention either internally (i.e., to the movements of the articulators) or externally (i.e., to the visual biofeedback display).

AIMS

This study addressed two objectives. First, it aimed to use single-subject experimental methods to collect additional evidence regarding the efficacy of visual-acoustic biofeedback treatment for children with /r/ misarticulation. Second, it compared the efficacy of this biofeedback intervention under two cueing conditions. In the external focus (EF) condition, participants' attention was directed exclusively to the external biofeedback display. In the internal focus (IF) condition, participants viewed a biofeedback display, but they also received articulatory cues encouraging an internal direction of attentional focus.

METHODS & PROCEDURES

Nine school-aged children were pseudo-randomly assigned to receive either IF or EF cues during 8 weeks of visual-acoustic biofeedback intervention. Accuracy in /r/ production at the word level was probed in three to five pre-treatment baseline sessions and in three post-treatment maintenance sessions. Outcomes were assessed using visual inspection and calculation of effect sizes for individual treatment trajectories. In addition, a mixed logistic model was used to examine across-subjects effects including phase (pre/post-treatment), /r/ variant (treated/untreated), and focus cue condition (internal/external).

OUTCOMES & RESULTS

Six out of nine participants showed sustained improvement on at least one treated /r/ variant; these six participants were evenly divided across EF and IF treatment groups. Regression results indicated that /r/ productions were significantly more likely to be rated accurate post- than pre-treatment. Internal versus external direction of focus cues was not a significant predictor of accuracy, nor did it interact significantly with other predictors.

CONCLUSIONS

The results are consistent with previous literature reporting that visual-acoustic biofeedback can produce measurable treatment gains in children who have not responded to previous intervention. These findings are also in keeping with previous research suggesting that biofeedback may be sufficient to establish an external attentional focus, independent of verbal cues provided. The finding that explicit articulator placement cues were not necessary for progress in treatment has implications for intervention practices for speech-sound disorders in children.

Speech Sound Disorders: What's Motor Got To Do With It?

Speech sound disorders (SSDs) are commonly viewed as involving impaired articulation and/or phonological skills. Speech language pathologists working with individuals with (SSDs) assess the articulation of speech sounds and the coordination of articulatory structures with other components of the speech mechanism, including the phonatory, respiratory, and resonatory subsystems. The sound system of the language and the rules that govern how phonemes are combined are equally critical for clinicians to explore. While the terms “articulation” and “phonology” provide clinicians with a framework for classification, children who are broadly identified with (SSDs) may also display characteristics of a motor speech impairment, which can obscure the decision making process with respect to both diagnosis and treatment. One such motor speech disorder is childhood apraxia of speech (CAS). The focus of this paper is to discuss motor speech deficits in children and to review research that aims to distinguish motor speech patterns in children with (SSDs) with and without CAS. We will also address the relationship between emerging speech motor and linguistic skills.

Limited acquisition and generalisation of rhotics with ultrasound visual feedback in childhood apraxia

Ultrasound visual feedback of the tongue is one treatment option for individuals with persisting speech sound errors. This study evaluated children's performance during acquisition and generalisation of American English rhotics using ultrasound feedback. Three children aged 10-13 with persisting speech sound errors associated with childhood apraxia of speech (CAS) were treated for 14 one-hour sessions. Two of the participants increased the accuracy of their rhotic production during practise trials within treatment sessions, but none demonstrated generalisation to untreated words. Lack of generalisation may be due to a failure to acquire the target with sufficient accuracy during treatment, or to co-existing linguistic weaknesses that are not addressed in a motor-based treatment. Results suggest a need to refine the intervention procedures for CAS and/or a need to identify appropriate candidates for intervention to optimise learning.

Treatment intensity and childhood apraxia of speech

BACKGROUND

Intensive treatment has been repeatedly recommended for the treatment of speech deficits in childhood apraxia of speech (CAS). However, differences in treatment outcomes as a function of treatment intensity have not been systematically studied in this population.

AIM

To investigate the effects of treatment intensity on outcome measures related to articulation, functional communication and speech intelligibility for children with CAS undergoing individual motor speech intervention.

METHODS & PROCEDURES

A total of 37 children (32-54 months of age) with CAS received 1×/week (lower intensity) or 2×/week (higher intensity) individual motor speech treatment for 10 weeks. Assessments were carried out before and after a 10-week treatment block to study the effects of variations in treatment intensity on the outcome measures.

OUTCOMES & RESULTS

The results indicated that only higher intensity treatment (2×/week) led to significantly better outcomes for articulation and functional communication compared with 1×/week (lower intensity) intervention. Further, neither lower nor higher intensity treatment yielded a significant change for speech intelligibility at the word or sentence level. In general, effect sizes for the higher intensity treatment groups were larger for most variables compared with the lower intensity treatment group.

CONCLUSIONS & IMPLICATIONS

Overall, the results of the current study may allow for modification of service delivery and facilitate the development of an evidence-based care pathway for children with CAS.

A Randomized Controlled Trial for Children With Childhood Apraxia of Speech Comparing Rapid Syllable Transition Treatment and the Nuffield Dyspraxia Programme-Third Edition

PURPOSE

This randomized controlled trial compared the experimental Rapid Syllable Transition (ReST) treatment to the Nuffield Dyspraxia Programme-Third Edition (NDP3; Williams & Stephens, 2004), used widely in clinical practice in Australia and the United Kingdom. Both programs aim to improve speech motor planning/programming for children with apraxia of speech (CAS), but they differ in types of stimuli used, level of stimulus complexity at initiation of treatment, and the principles of motor learning that they apply.

METHOD

Treatment was delivered to 26 children with mild to severe CAS aged 4-12 years through trained and supervised speech-language pathology students in 1-hr sessions, 4 days a week for 3 weeks at a university clinic. Articulation and prosodic accuracy were assessed at pretreatment, 1 week, 1 month, and 4 months posttreatment using blinded independent assessors to compare treatment, maintenance, and generalization effects.

RESULTS

The ReST and NDP3 treatments demonstrated large treatment effects. ReST maintained treatment gains from 1-week to 4-months posttreatment more effectively than the NDP3. Significant generalization to untreated stimuli was observed for both ReST and NDP3.

CONCLUSIONS

ReST and NDP3 have strong evidence of treatment and generalization gains in children with CAS when delivered intensively. Overall, ReST has greater external evidence from multiple sources but both treatments have support for clinical use.

Cross-linguistic generalization in the treatment of two sequential Spanish-English bilingual children with speech sound disorders

PURPOSE

The effect of bilingual service delivery on treatment of speech sound disorders (SSDs) in bilingual children is largely unknown. Bilingual children with SSDs are typically provided intervention in only one language, although research suggests dual-language instruction for language disorders is best practice for bilinguals. This study examined cross-linguistic generalization of bilingual intervention in treatment of two 5-year-old sequential bilingual boys with SSDs (one with Childhood Apraxia of Speech), hypothesizing that selecting and treating targets in both languages would result in significant overall change in their English and Spanish speech systems.

METHOD

A multiple baseline across behaviours design was used to measure treatment effectiveness for two targets per child. Children received treatment 2-3 times per week for 8 weeks and in Spanish for at least 2 of every 3 days. Ongoing treatment performance was measured in probes in both languages; overall speech skills were compared pre- and post-treatment.

RESULT

Both children's speech improved in both languages with similar magnitude; there was improvement in some non-treated errors.

CONCLUSION

Treating both languages had an overall positive effect on these bilingual children's speech. Future bilingual intervention research should explore alternating treatments designs, efficiency of monolingual vs bilingual treatment, different language and bilingual backgrounds, and between-group comparisons.

Online crowdsourcing for efficient rating of speech: a validation study

Blinded listener ratings are essential for valid assessment of interventions for speech disorders, but collecting these ratings can be time-intensive and costly. This study evaluated the validity of speech ratings obtained through online crowdsourcing, a potentially more efficient approach. 100 words from children with /r/ misarticulation were electronically presented for binary rating by 35 phonetically trained listeners and 205 naïve listeners recruited through the Amazon Mechanical Turk (AMT) crowdsourcing platform. Bootstrapping was used to compare different-sized samples of AMT listeners against a "gold standard" (mode across all trained listeners) and an "industry standard" (mode across bootstrapped samples of three trained listeners). There was strong overall agreement between trained and AMT listeners. The "industry standard" level of performance was matched by bootstrapped samples with n = 9 AMT listeners. These results support the hypothesis that valid ratings of speech data can be obtained in an efficient manner through AMT. Researchers in communication disorders could benefit from increased awareness of this method.

LEARNING OUTCOMES

Readers will be able to (a) discuss advantages and disadvantages of data collection through the crowdsourcing platform Amazon Mechanical Turk (AMT), (b) describe the results of a validity study comparing samples of AMT listeners versus phonetically trained listeners in a speech-rating task.

Retroflex versus bunched in treatment for rhotic misarticulation: evidence from ultrasound biofeedback intervention

PURPOSE

To document the efficacy of ultrasound biofeedback treatment for misarticulation of the North American English rhotic in children. Because of limited progress in the first cohort, a series of two closely related studies was conducted in place of a single study. The studies differed primarily in the nature of tongue-shape targets (e.g., retroflex, bunched) cued during treatment.

METHOD

Eight participants received 8 weeks of individual ultrasound biofeedback treatment targeting rhotics. In Study 1, all 4 participants were cued to match a bunched tongue-shape target. In Study 2, participants received individualized cues aimed at eliciting the tongue shape most facilitative of perceptually correct rhotics.

RESULTS

Participants in Study 1 showed only minimal treatment effects. In Study 2, all participants demonstrated improved production of rhotics in untreated words produced without biofeedback, with large to very large effect sizes.

CONCLUSIONS

The results of Study 2 indicate that with proper parameters of treatment, ultrasound biofeedback can be a highly effective intervention for children with persistent rhotic errors. In addition, qualitative comparison of Studies 1 and 2 suggests that treatment for the North American English rhotic should include opportunities to explore different tongue shapes, to find the most facilitative variant for each individual speaker.

Segmental and prosodic approaches to accent management

PURPOSE

This study investigated the relative outcomes of segmental and prosodic training of nonnative speakers of American English.

METHOD

The study used a single-subject, alternating treatments, multiple baseline design with replication across participants and counterbalanced for order effect. Participants were 4 adult male native Hindi speakers proficient in English. Two participants received ABABCACA (A = baseline/withdrawal, B = segmental training, C = prosody training), and 2 participants received ACACBABA, with a minimum of 5 sessions per phase. Segmental accuracy and prosodic accuracy were probed at each session, as were perception of accentedness and ease of understanding.

RESULTS

Visual assessment of data and effect size calculation demonstrated that segmental and prosody training resulted in increased accuracy of pronunciation and prosody patterns, respectively, and those improvements appeared to be maintained over the short term. Listeners perceived lesser accent and easier understanding as a result of the combination of segmental and prosody training. The findings are uncertain with respect to the relative contribution of segmental and prosody training, and they may be speaker dependent, but the data do suggest that both components are important.

CONCLUSION

Accent management, consisting of both segmental and prosody training, yielded positive outcomes. Further research with native language speakers of other languages is important to verify and expand on these findings.

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

PURPOSE

The purpose of this study was to determine if randomized variable practice, a central component of concurrent treatment, would be effective and efficient in treating childhood apraxia of speech (CAS). Concurrent treatment is a treatment program that takes the speech task hierarchy and randomizes it so that all tasks are worked on in one session. Previous studies have shown the treatment program to be effective and efficient in treating phonological and articulation disorders. The program was adapted to be used with children with CAS.

METHOD

A research design of multiple baselines across participants was used. Probes of generalization to untaught words were administered every fifth session. Three children, ranging in age from 4 to 6 years old, were the participants. Data were collected as percent correct productions during baseline, treatment, and probes of generalization of target sounds to untaught words and three-word phrases.

RESULTS

All participants showed an increase in correct productions during treatment and during probes. Effect sizes (standard mean difference) for treatment were 3.61-5.00, and for generalization probes, they were 3.15-8.51.

CONCLUSIONS

The results obtained from this study suggest that randomized variable practice as used in concurrent treatment can be adapted for use in treating children with CAS. Replication of this study with other children presenting CAS will be needed to establish generality of the findings.

The Application of Motor Learning Concepts to the Treatment of Children with Compensatory Speech Sound Errors

Children with cleft palate frequently present with compensatory speech sound errors, which are generally targeted in treatment. Often, treatment consists of different phonetic teaching methods and procedures that are delivered via an operant learning paradigm; however, there are other theoretical models of learning that may prove more efficacious for modifying compensatory errors. Motor learning is a teaching/learning methodology that has an extensive body of research to support its use in the acquisition and development of motor skills. Currently, researchers are using motor learning paradigms in the treatment of different speech disorders and evidence on efficacy is being collected. This paper will discuss motor learning as a methodology for treating compensatory speech sound errors in an effective and efficient manner.

Rapid Syllable Transitions (ReST) treatment for Childhood Apraxia of Speech: the effect of lower dose-frequency

This study investigated the effectiveness of twice-weekly Rapid Syllable Transitions (ReST) treatment for Childhood Apraxia of Speech (CAS). ReST is an effective treatment at a frequency of four sessions a week for three consecutive weeks. In this study we used a multiple-baselines across participants design to examine treatment efficacy for four children with CAS, aged four to eight years, who received ReST treatment twice a week for six weeks. The children's ability to acquire new skills, generalize these skills to untreated items and maintain the skills after treatment was examined. All four children improved their production of the target items. Two of the four children generalized the treatment effects to similar untreated pseudo words and all children generalized to untreated real words. During the maintenance phase, all four participants maintained their skills to four months post-treatment, with a stable rather than rising profile. This study shows that ReST treatment delivered twice-weekly results in significant retention of treatment effects to four months post-treatment and generalization to untrained but related speech behaviors. Compared to ReST therapy four times per week, the twice-weekly frequency produces similar treatment gains but no ongoing improvement after the cessation of treatment. This implies that there may be a small but significant benefit of four times weekly therapy compared with twice-weekly ReST therapy.

LEARNING OUTCOMES

Readers will be able to define dose-frequency, and describe how this relates to overall intervention intensity. Readers will be able to explain the acquisition, generalization and maintenance effects in the study and describe how these compare to higher dose frequency treatments. Readers will recognize that the current findings give preliminary support for high dose-frequency CAS treatment.

A systematic review of treatment outcomes for children with childhood apraxia of speech

PURPOSE

To present a systematic review of single-case experimental treatment studies for childhood apraxia of speech (CAS).

METHOD

A search of 9 databases was used to find peer-reviewed treatment articles from 1970 to 2012 of all levels of evidence with published communication outcomes for children with CAS. Improvement rate differences (IRDs) were calculated for articles with replicated (n > 1), statistically compared treatment and generalization evidence.

RESULTS

Forty-two articles representing Phase I and II single-case experimental designs (SCEDs; n = 23) or case series or description studies ( n = 19) were analyzed. Six articles showed high CAS diagnosis confidence. Of the 13 approaches within the 23 SCED articles, treatments were primarily for speech motor skills ( n = 6), linguistic skills ( n = 5), or augmentative and alternative communication ( n = 2). Most participants responded positively to treatment, but only 7 of 13 approaches in SCED studies reported maintenance and/or generalization of treatment effects. Three approaches had preponderant evidence (Smith, 1981). IRD effect sizes were calculated for Integral Stimulation/Dynamic Temporal and Tactile Cueing, Rapid Syllable Transition Treatment, and Integrated Phonological Awareness Intervention.

CONCLUSIONS

At least 3 treatments have sufficient evidence for Phase III trials and interim clinical practice. In the future, efficacy needs to be established via maintenance and generalization measures.

Effects of Blocked Versus Random Practice on Speech Motor Skill Acquisition and Retention

Purpose:

The effect of blocked practice (BP) versus random practice (RP) on the acquisition and retention of novel speech motor sequences in healthy young adults was examined.

Method:

Twenty participants underwent a comparable amount of practice in either blocked or random order and were tested for retention the following day. Behavioral accuracy and kinematic measures of timing were obtained.

Results:

Performance levels were significantly higher, overall, for the BP group compared with the RP during the acquisition phases. During the retention test, the RP group was significantly more accurate than the BP group. Similar trends were noted, but did not reach significance, for kinematic measures.

Conclusion:

Consistent with patterns established in the limb motor learning literature, our results indicate that BP leads to higher overall performance levels (though not necessarily greater gains in performance) during acquisition, whereas improved performance at retention is facilitated by RP.

Sound production treatment: effects of blocked and random practice

PURPOSE

This investigation was designed to further the development of a treatment for acquired apraxia of speech (AOS), Sound Production Treatment (SPT), by examining the effects of blocked and random practice.

METHOD

A multiple-baseline design across participants and behaviors was used with 6 speakers with chronic AOS and aphasia. Accuracy of production of target sounds in treated and untreated words produced in probe sessions served as the primary dependent variable. Stimulus generalization was also measured to phrase production and sentence completion. Participants received SPT applied with blocked presentation of treatment words (SPT-blocked) and SPT applied with random presentation of treatment words (SPT-random).

RESULTS

Increases in accuracy of articulation of target sounds in treated words were observed for all participants for both conditions of treatment. SPT-random appeared to be associated with better maintenance for 2 participants. Generalization to untreated words was positive for all participants for SPT-random and SPT-blocked. Stimulus generalization effects varied across participants and measurement conditions; patterns of generalization did not appear to be associated with treatment condition.

CONCLUSIONS

There may be an advantage for SPT-random for some speakers with AOS. Findings from the nonspeech motor learning literature may not translate directly to the treatment of AOS.

Motor-based intervention protocols in treatment of childhood apraxia of speech (CAS)

This paper reviews current trends in treatment for childhood apraxia of speech (CAS), with a particular emphasis on motor-based intervention protocols. The paper first briefly discusses how CAS fits into the typology of speech sound disorders, followed by a discussion of the potential relevance of principles derived from the motor learning literature for CAS treatment. Next, different motor-based treatment protocols are reviewed, along with their evidence base. The paper concludes with a summary and discussion of future research needs.

Effects of practice schedules on speech motor learning

The aim of this study was to evaluate the effects of various practice schedules on learning a novel speech task. Forty healthy Cantonese speakers were asked to learn to produce a Cantonese phrase with two target utterance durations (2500 and 3500 milliseconds). They were randomly assigned to one of four learning conditions, each completing a different practice schedule, namely Blocked only, Random only, Blocked-then-Random, and Random-then-Blocked. Two retention tests (one immediate and one delayed) and a transfer test were administered. The four groups of participants showed different patterns of learning, but achieved comparable levels of performance at the end of the acquisition phase. However, participants in the Blocked only condition were less able to differentiate the two target durations than those in the Random only condition during retention. Furthermore, participants who received both blocked and random practice were less adversely affected by the secondary task during the transfer test than those who received either blocked or random practice alone. These findings suggest that mixed practice schedules are more effective than either blocked or random practice, especially in transferring the acquired speech motor skills to a cognitively demanding situation. The results have clinical implications regarding optimal practice schedules for treatment intervention.

Treatment for acquired apraxia of speech: examination of treatment intensity and practice schedule

PURPOSE

The authors designed this investigation to extend the development of a treatment for acquired apraxia of speech (AOS)--sound production treatment (SPT)--by examining the effects of 2 treatment intensities and 2 schedules of practice.

METHOD

The authors used a multiple baseline design across participants and behaviors with 4 speakers with chronic AOS and aphasia. Accuracy of production of trained and untrained words in phrases served as the dependent measure. Participants received 4 permutations of SPT (i.e., intensive-blocked, intensive-random, traditional-blocked, and traditional-random) applied sequentially to different lists of words.

RESULTS

Positive changes in accuracy of articulation were observed for all participants for all phases of treatment. Two participants had a slightly poorer response to the traditional-random application of treatment. However, no clinically meaningful differences were noted among treatment applications when follow-up data were considered.

CONCLUSIONS

Findings from this preliminary Phase II investigation suggest that similar outcomes may be achieved with SPT applied with different treatment intensities and different practice schedules. Extending treatment to achieve higher levels of accuracy may have improved maintenance effects, which may have revealed possible differences among conditions. In addition, overlap in methods used for random and blocked practice may have minimized distinctions between these conditions.

A comparison of two treatments for childhood apraxia of speech: methods and treatment protocol for a parallel group randomised control trial

Background

Childhood Apraxia of Speech is an impairment of speech motor planning that manifests as difficulty producing the sounds (articulation) and melody (prosody) of speech. These difficulties may persist through life and are detrimental to academic, social, and vocational development. A number of published single subject and case series studies of speech treatments are available. There are currently no randomised control trials or other well designed group trials available to guide clinical practice.

Methods/Design

A parallel group, fixed size randomised control trial will be conducted in Sydney, Australia to determine the efficacy of two treatments for Childhood Apraxia of Speech: 1) Rapid Syllable Transition Treatment and the 2) Nuffield Dyspraxia Programme – Third edition. Eligible children will be English speaking, aged 4–12 years with a diagnosis of suspected CAS, normal or adjusted hearing and vision, and no comprehension difficulties or other developmental diagnoses. At least 20 children will be randomised to receive one of the two treatments in parallel. Treatments will be delivered by trained and supervised speech pathology clinicians using operationalised manuals. Treatment will be administered in 1-hour sessions, 4 times per week for 3 weeks. The primary outcomes are speech sound and prosodic accuracy on a customised 292 item probe and the Diagnostic Evaluation of Articulation and Phonology inconsistency subtest administered prior to treatment and 1 week, 1 month and 4 months post-treatment. All post assessments will be completed by blinded assessors. Our hypotheses are: 1) treatment effects at 1 week post will be similar for both treatments, 2) maintenance of treatment effects at 1 and 4 months post will be greater for Rapid Syllable Transition Treatment than Nuffield Dyspraxia Programme treatment, and 3) generalisation of treatment effects to untrained related speech behaviours will be greater for Rapid Syllable Transition Treatment than Nuffield Dyspraxia Programme treatment. This protocol was approved by the Human Research Ethics Committee, University of Sydney (#12924).

Discussion

This will be the first randomised control trial to test treatment for CAS. It will be valuable for clinical decision-making and providing evidence-based services for children with CAS.

Trial Registration

Australian New Zealand Clinical Trials Registry: ACTRN12612000744853

Feedback frequency in treatment for childhood apraxia of speech

PURPOSE

To examine the role of feedback frequency in treatment for childhood apraxia of speech (CAS). Reducing the frequency of feedback enhances motor learning, and recently, such feedback frequency reductions have been recommended for the treatment of CAS. However, no published studies have explicitly compared different feedback frequencies in this population.

METHOD

Using an alternating treatments single-subject design with multiple baselines across behaviors, retention and transfer of learning were compared following high-frequency feedback and low-frequency feedback in 4 children with CAS. Feedback frequency was manipulated in the context of an integral stimulation treatment. Changes in perceptual accuracy were quantified with effect sizes and were compared across conditions.

RESULTS

Findings were mixed, with 2 children showing an advantage for low-frequency feedback, 1 child showing a small advantage for high-frequency feedback, and 1 child showing no clear improvement in either condition.

CONCLUSION

These findings suggest that reducing the frequency of feedback may be beneficial for some children with CAS, although this may vary with the child's age or severity of apraxia. Caution is warranted in extrapolating from the nonspeech motor learning literature to speech treatment for CAS. Finally, this study contributes another replication to the literature on the efficacy of integral stimulation treatment for children with CAS.