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

Assessing ultrasound probe stabilization for quantifying speech production contrasts using the Adjustable Laboratory Probe Holder for UltraSound (ALPHUS)

Ultrasound imaging of the tongue is biased by the probe movements relative to the speaker's head. Two common remedies are restricting or algorithmically compensating for such movements, each with its own challenges. We describe these challenges in details and evaluate an open-source, adjustable probe stabilizer for ultrasound (ALPHUS), specifically designed to address these challenges by restricting uncorrectable probe movements while allowing for correctable ones (e.g., jaw opening) to facilitate naturalness. The stabilizer is highly modular and adaptable to different users (e.g., adults and children) and different research/clinical needs (e.g., imaging in both midsagittal and coronal orientations). The results of three experiments show that probe movement over uncorrectable degrees of freedom was negligible, while movement over correctable degrees of freedom that could be compensated through post-processing alignment was relatively large, indicating unconstrained articulation over parameters relevant for natural speech. Results also showed that probe movements as small as 5 mm or 2 degrees can neutralize phonemic contrasts in ultrasound tongue positions. This demonstrates that while stabilized but uncorrected ultrasound imaging can provide reliable tongue shape information (e.g., curvature or complexity), accurate tongue position (e.g., height or backness) with respect to vocal tract hard structure needs correction for probe displacement relative to the head.

Intervention for residual speech errors in adolescents and adults: A systematised review

When speech sound errors persist beyond childhood they are classified as residual speech errors (RSE) and may have detrimental impacts on an individual's social, educational and employment participation. Despite this, individuals who present with RSE are usually not prioritised on large caseloads. The aim of this literature review was to examine what intervention approaches are available in remediating RSE, and how effective are they for adolescents and adults? A systematised review was undertaken. Comprehensive and systematic searching included search of terms across seven databases, forward and reverse citation searching, and key author contact. Thirty articles underwent critical appraisal before data extraction. Inductive thematic analysis was done before completion of a narrative review. Twenty-three (76.6%) of the articles were from the US and most studies involved intervention for 'r' (90%). Intervention approaches for RSE involved traditional articulation therapy, auditory perceptual training, instrumental approaches, and approaches based on principles of motor learning. Twenty-one studies (70%) investigated the use of more than one intervention approach. Measures of intervention efficacy varied between studies; however, any intervention approach tended to be more successful if delivered in a more intensive schedule. A variety of approaches can be used for RSE, but a combination of high intensity, traditional therapy with adjunctive instrumental biofeedback may be most effective, especially with highly motivated individuals. Unfortunately, this usually requires costly equipment and training to implement. More information about the best dosage and intensity intervention for RSE, evaluated for a larger number of phonemes across other languages and dialects is required.

Statistical evaluation of tongue capability with visual feedback

BACKGROUND

Analysis of tongue movement would benefit from a reference showcasing healthy tongue capability. We aimed to develop a reference of tongue capability and evaluated the role of visual feedback on the expression of movement.

METHODS

Using a wireless tracking intraoral wearable device, we composed probability distributions of the tongue tip as subjects were asked to explore the entire sensing surface area. Half of the 32 subjects received live visual feedback of the location of the center of the tongue tip contact.

RESULTS

We observed that the visual feedback group was 51.0% more consistent with each other in the position domain, explored 21.5% more sensing surface area, and was 50.7% more uniformly distributed. We found less consistent results when we evaluated velocity and acceleration.

CONCLUSION

Visual feedback best established a healthy capability reference which can be used for designing new interfaces, quantifying tongue ability, developing new diagnostic and rehabilitation techniques, and studying underlying mechanisms of tongue motor control.

Neural Changes in Children With Residual Speech Sound Disorder After Ultrasound Biofeedback Speech Therapy

PURPOSE

Children with residual speech sound disorders (RSSD) have shown differences in neural function for speech production, as compared to their typical peers; however, information about how these differences may change over time and relative to speech therapy is needed. To address this gap, we used functional magnetic resonance imaging (fMRI) to examine functional activation and connectivity on adaptations of the syllable repetition task (SRT-Early Sounds and SRT-Late Sounds) in children with RSSD before and after a speech therapy program.

METHOD

Sixteen children with RSSD completed an fMRI experiment before (Time 1) and after (Time 2) a speech therapy program with ultrasound visual feedback for /ɹ/ misarticulation. Progress in therapy was measured via perceptual ratings of productions of untreated /ɹ/ word probes. To control for practice effects and developmental change in patterns of activation and connectivity, 17 children with typical speech development (TD) completed the fMRI at Time 1 and Time 2. Functional activation was analyzed using a region-of-interest approach and functional connectivity was analyzed using a seed-to-voxel approach.

RESULTS

Children with RSSD showed a range of responses to therapy. After correcting for multiple comparisons, we did not observe any statistically significant cross-sectional differences or longitudinal changes in functional activation. A negative relationship between therapy effect size and functional activation in the left visual association cortex was on the SRT-Late Sounds after therapy, but it did not survive correction for multiple comparisons. Significant longitudinal changes in functional connectivity were observed for the RSSD group on SRT-Early Sounds and SRT-Late Sounds, as well as for the TD group on the SRT-Early Sounds. RSSD and TD groups showed connectivity differences near the left insula on the SRT-Late Sounds at Time 2.

CONCLUSION

RSSD and treatment with ultrasound visual feedback may thus be associated with neural differences in speech motor and visual association processes recruited for speech production.

The impact of age on the treatment of late-acquired sounds in children with speech sound disorders

The question of 'when' to treat speech sounds is often posed in the context of normative data. The new normative data suggest that speech sounds such as /ɹ/ and /l/ are acquired earlier than previously thought. The present study compared the treatment of late-acquired sounds between two age groups of English-speaking children: Young children (4-5) and Old children (7-8). Eight monolingual children with speech sound disorder (SSD) participated in the study. Each child received a criterion-based, standardised, two-phase therapy protocol. Treatment efficacy was measured by examining children's accuracy on real world speech probes. Treatment efficiency was measured by calculating the number of sessions required to meet the exit criterion and the mean session duration. For treatment efficacy, young children learned treated sounds as effectively as oldchildren did. For treatment efficiency, both groups required a comparable number of sessions, but young children required longer sessions than old children. The results suggest that delaying treatment of individual speech sounds is unnecessary and that a range of sounds should be considered as potential treatment targets.

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.

Crowdsourced Perceptual Ratings of Voice Quality in People With Parkinson's Disease Before and After Intensive Voice and Articulation Therapies: Secondary Outcome of a Randomized Controlled Trial

PURPOSE

Limited research has examined the suitability of crowdsourced ratings to measure treatment effects in speakers with Parkinson's disease (PD), particularly for constructs such as voice quality. This study obtained measures of reliability and validity for crowdsourced listeners' ratings of voice quality in speech samples from a published study. We also investigated whether aggregated listener ratings would replicate the original study's findings of treatment effects based on the Acoustic Voice Quality Index (AVQI) measure.

METHOD

This study reports a secondary outcome measure of a randomized controlled trial with speakers with dysarthria associated with PD, including two active comparators (Lee Silverman Voice Treatment [LSVT LOUD] and LSVT ARTIC), an inactive comparator (untreated PD), and a healthy control group. Speech samples from three time points (pretreatment, posttreatment, and 6-month follow-up) were presented in random order for rating as "typical" or "atypical" with respect to voice quality. Untrained listeners were recruited through the Amazon Mechanical Turk crowdsourcing platform until each sample had at least 25 ratings.

RESULTS

Intrarater reliability for tokens presented repeatedly was substantial (Cohen's κ = .65-.70), and interrater agreement significantly exceeded chance level. There was a significant correlation of moderate magnitude between the AVQI and the proportion of listeners classifying a given sample as "typical." Consistent with the original study, we found a significant interaction between group and time point, with the LSVT LOUD group alone showing significantly higher perceptually rated voice quality at posttreatment and follow-up relative to the pretreatment time point.

CONCLUSIONS

These results suggest that crowdsourcing can be a valid means to evaluate clinical speech samples, even for less familiar constructs such as voice quality. The findings also replicate the results of the study by Moya-Galé et al. (2022) and support their functional relevance by demonstrating that the effects of treatment measured acoustically in that study are perceptually apparent to everyday listeners.

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.

Tutorial: Using Visual-Acoustic Biofeedback for Speech Sound Training

PURPOSE

This tutorial summarizes current practices using visual-acoustic biofeedback (VAB) treatment to improve speech outcomes for individuals with speech sound difficulties. Clinical strategies will focus on residual distortions of /ɹ/.

METHOD

Summary evidence related to the characteristics of VAB and the populations that may benefit from this treatment are reviewed. Guidelines are provided for clinicians on how to use VAB with clients to identify and modify their productions to match an acoustic representation. The clinical application of a linear predictive coding spectrum is emphasized.

RESULTS

Successful use of VAB requires several key factors including clinician and client comprehension of the acoustic representation, appropriate acoustic target and template selection, as well as appropriate selection of articulatory strategies, practice schedules, and feedback models to scaffold acquisition of new speech sounds.

CONCLUSION

Integrating a VAB component in clinical practice offers additional intervention options for individuals with speech sound difficulties and often facilitates improved speech sound acquisition and generalization outcomes.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21817722.

Baseline Stimulability Predicts Patterns of Response to Traditional and Ultrasound Biofeedback Treatment for Residual Speech Sound Disorder

PURPOSE

This study aimed to identify predictors of response to treatment for residual speech sound disorder (RSSD) affecting English rhotics. Progress was tracked during an initial phase of traditional motor-based treatment and a longer phase of treatment incorporating ultrasound biofeedback. Based on previous literature, we focused on baseline stimulability and sensory acuity as predictors of interest.

METHOD

Thirty-three individuals aged 9-15 years with residual distortions of /ɹ/ received a course of individual intervention comprising 1 week of intensive traditional treatment and 9 weeks of ultrasound biofeedback treatment. Stimulability for /ɹ/ was probed prior to treatment, after the traditional treatment phase, and after the end of all treatment. Accuracy of /ɹ/ production in each probe was assessed with an acoustic measure: normalized third formant (F3)-second formant (F2) distance. Model-based clustering analysis was applied to these acoustic measures to identify different average trajectories of progress over the course of treatment. The resulting clusters were compared with respect to acuity in auditory and somatosensory domains.

RESULTS

All but four individuals were judged to exhibit a clinically significant response to the combined course of treatment. Two major clusters were identified. The "low stimulability" cluster was characterized by very low accuracy at baseline, minimal response to traditional treatment, and strong response to ultrasound biofeedback. The "high stimulability" group was more accurate at baseline and made significant gains in both traditional and ultrasound biofeedback phases of treatment. The clusters did not differ with respect to sensory acuity.

CONCLUSIONS

This research accords with clinical intuition in finding that individuals who are more stimulable at baseline are more likely to respond to traditional intervention, whereas less stimulable individuals may derive greater relative benefit from biofeedback.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.20422236.

Telepractice Treatment of Residual Rhotic Errors Using App-Based Biofeedback: A Pilot Study

PURPOSE

Although mobile apps are used extensively by speech-language pathologists, evidence for app-based treatments remains limited in quantity and quality. This study investigated the efficacy of app-based visual-acoustic biofeedback relative to nonbiofeedback treatment using a single-case randomization design. Because of COVID-19, all intervention was delivered via telepractice.

METHOD

Participants were four children aged 9-10 years with residual errors affecting American English /ɹ/. Using a randomization design, individual sessions were randomly assigned to feature practice with or without biofeedback, all delivered using the speech app Speech Therapist's App for /r/ Treatment. Progress was assessed using blinded listener ratings of word probes administered at baseline, posttreatment, and immediately before and after each treatment session.

RESULTS

All participants showed a clinically significant response to the overall treatment package, with effect sizes ranging from moderate to very large. One participant showed a significant advantage for biofeedback over nonbiofeedback treatment, although the order of treatment delivery poses a potential confound for interpretation in this case.

CONCLUSIONS

While larger scale studies are needed, these results suggest that app-based treatment for residual errors can be effective when delivered via telepractice. These results are compatible with previous findings in the motor learning literature regarding the importance of treatment dose and the timing of feedback conditions.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.18461576.

Moving Beyond Single Word Acquisition of Speech Sounds to Connected Speech Development With Dynamic Assessment

PURPOSE

The aim of this study was to document speech sound development across early childhood from a dynamic assessment (DA) perspective that captures a breadth of linguistic environments using the Glaspey Dynamic Assessment of Phonology (Glaspey, 2019), as well as to provide normative data for speech-language pathologists to compare speech skills when making clinical decisions and provide historical context. Targets of English were evaluated via DA for the (a) age of acquisition in single words; (b) continued development through connected speech; (c) early, mid, and late sequence; and (d) differences between single word and connected speech productions.

METHOD

Data were extracted from the reported results of the norming study for the Glaspey Dynamic Assessment of Phonology, which included a representative sample of 880 children ages 3 years to 10;11 (years;months). Comparisons were made with 49 items including multisyllabic words, clusters, and phonemes of English across word positions.

RESULTS

Assessment with DA showed that acquisition in single words is nearly complete by age 6 years with a 90% mastery level, and the sequence suggests an Early-13, Mid-16, and Late-14 for items by word position. In connected speech, a wider range of progression is evident from the emergence of sound production at 50%, 75%, and 90% mastery levels with observed changes between ages 3 and 10 years.

CONCLUSIONS

Given a DA approach across connected linguistic environments, children continue to progress in their development of speech sounds from early childhood well into their school-age years and for some sounds beyond the age of 10 years. DA challenges the language system to better reflect children's developmental progression.

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

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

Visual feedback of the tongue influences speech adaptation to a physical modification of the oral cavity

Studies examining sensorimotor adaptation of speech to changing sensory conditions have demonstrated a central role for both auditory and somatosensory feedback in speech motor learning. The potential influence of visual feedback of oral articulators, which is not typically available during speech production but may nonetheless enhance oral motor control, remains poorly understood. The present study explores the influence of ultrasound visual feedback of the tongue on adaptation of speech production (focusing on the sound /s/) to a physical perturbation of the oral articulators (prosthesis altering the shape of the hard palate). Two visual feedback groups were tested that differed in the two-dimensional plane being imaged (coronal or sagittal) during practice producing /s/ words, along with a no-visual-feedback control group. Participants in the coronal condition were found to adapt their speech production across a broader range of acoustic spectral moments and syllable contexts than the no-feedback controls. In contrast, the sagittal group showed reduced adaptation compared to no-feedback controls. The results indicate that real-time visual feedback of the tongue is spontaneously integrated during speech motor adaptation, with effects that can enhance or interfere with oral motor learning depending on compatibility of the visual articulatory information with requirements of the speaking task.

Comparing Biofeedback Types for Children With Residual /ɹ/ Errors in American English: A Single-Case Randomization Design

Purpose Research comparing different biofeedback types could lead to individualized treatments for those with residual speech errors. This study examines within-treatment response to ultrasound and visual-acoustic biofeedback, as well as generalization to untrained words, for errors affecting the American English rhotic /ɹ/. We investigated whether some children demonstrated greater improvement in /ɹ/ during ultrasound or visual-acoustic biofeedback. Each participant received both biofeedback types. Individual predictors of treatment response (i.e., age, auditory-perceptual skill, oral somatosensory skill, and growth mindset) were also explored. Method Seven children ages 9-16 years with residual rhotic errors participated in 10 treatment visits. Each visit consisted of two conditions: 45 min of ultrasound biofeedback and 45 min of visual-acoustic biofeedback. The order of biofeedback conditions was randomized within a single-case experimental design. Acquisition of /ɹ/ was evaluated through acoustic measurements (normalized F3-F2 difference) of selected nonbiofeedback productions during practice. Generalization of /ɹ/ was evaluated through acoustic measurements and perceptual ratings of pretreatment/posttreatment probes. Results Five participants demonstrated acquisition of practiced words during the combined treatment package. Three participants demonstrated a clinically significant degree of generalization to untreated words on posttreatment probes. Randomization tests indicated one participant demonstrated a significant advantage for visual-acoustic over ultrasound biofeedback. Participants' auditory-perceptual acuity on an /ɹ/-/w/ identification task was identified as a possible correlate of generalization following treatment. Conclusions Most participants did not demonstrate a statistically significant difference in acoustic productions between the ultrasound and visual-acoustic conditions, but one participant showed greater improvement in /ɹ/ during visual-acoustic biofeedback. Supplemental Material https://doi.org/10.23641/asha.14881101.

Use of ultrasound visual feedback in speech intervention for children with cochlear implants

The purpose of the present study was to evaluate the efficacy of ultrasound visual feedback in speech intervention for young children with cochlear implants. Although ultrasound technology has been used for intervention in children with speech sound disorders, there is little systematic evidence regarding relative efficacy of ultrasound visual feedback for young children with cochlear implants. Two children with cochlear implants participated in this study. The children's articulation was tested using Goldman-Fristoe Test of Articulation-2 and probes. Therapy was provided semi-weekly for 30-minute sessions over the course of nine to 10 weeks. Visual inspection showed an increasing trend in production accuracy to the criterion accuracy of 80% for target sounds. Maintenance of skills were observed at two weeks and two months post-intervention. The results of this study indicated that ultrasound visual feedback is likely an effective intervention tool for treating speech sound disorders in children with cochlear implants. Future studies including a larger sample size should be conducted to verify these findings.

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.

Auditory-perceptual acuity in rhotic misarticulation: baseline characteristics and treatment response

The rhotic sound /r/ is one of the latest-emerging sounds in English, and many children receive treatment for residual errors affecting /r/ that persist past the age of 9. Auditory-perceptual abilities of children with residual speech errors are thought to be different from their typically developing peers. This study examined auditory-perceptual acuity in children with residual speech errors affecting /r/ and the relation of these skills to production accuracy, both before and after a period of treatment incorporating visual biofeedback. Identification of items along an /r/-/w/ continuum was assessed prior to treatment. Production accuracy for /r/ was acoustically measured from standard/r/stimulability probes elicited before and after treatment. Fifty-nine children aged 9-15 with residual speech errors (RSE) affecting /r/ completed treatment, and forty-eight age-matched controls who completed the same auditory-perceptual task served as a comparison group. It was hypothesized that children with RSE would show lower auditory-perceptual acuity than typically developing speakers and that higher auditory-perceptual acuity would be associated with more accurate production before treatment. It was also hypothesized that auditory-perceptual acuity would serve as a mediator of treatment response. Results indicated that typically developing children have more acute perception of the /r/-/w/ contrast than children with RSE. Contrary to hypothesis, baseline auditory-perceptual acuity for /r/ did not predict baseline production severity. For baseline auditory-perceptual acuity in relation to biofeedback efficacy, there was an interaction between auditory-perceptual acuity and gender, such that higher auditory-perceptual acuity was associated with greater treatment response in female, but not male, participants.

Using Crowdsourced Listeners' Ratings to Measure Speech Changes in Hypokinetic Dysarthria: A Proof-of-Concept Study

Purpose Interventions for speech disorders aim to produce changes that are not only acoustically measurable or perceptible to trained professionals but are also apparent to naive listeners. Due to challenges associated with obtaining ratings from suitably large listener samples, however, few studies currently evaluate speech interventions by this criterion. Online crowdsourcing technologies could enhance the measurement of intervention effects by making it easier to obtain real-world listeners' ratings. Method Stimuli, drawn from a published study by Sapir et al. ("Effects of intensive voice treatment (Lee Silverman Voice Treatment [LSVT]) on vowel articulation in dysarthric individuals with idiopathic Parkinson disease: Acoustic and perceptual findings" in Journal of Speech, Language, and Hearing Research, 50(4), 2007), were words produced by individuals who received intensive treatment (LSVT LOUD) for hypokinetic dysarthria secondary to Parkinson's disease. Thirty-six online naive listeners heard randomly ordered pairs of words elicited pre- and posttreatment and reported which they perceived as "more clearly articulated." Results Mixed-effects logistic regression indicated that words elicited posttreatment were significantly more likely to be rated "more clear." Across individuals, acoustically measured magnitude of change was significantly correlated with pre-post difference in listener ratings. Conclusions These results partly replicate the findings of Sapir et al. (2007) and demonstrate that their acoustically measured changes are detectable by everyday listeners. This supports the viability of using crowdsourcing to obtain more functionally relevant measures of change in clinical speech samples. Supplemental Material https://doi.org/10.23641/asha.12170112.

Protocol for Correcting Residual Errors with Spectral, ULtrasound, Traditional Speech therapy Randomized Controlled Trial (C-RESULTS RCT)

Background

Speech sound disorder in childhood poses a barrier to academic and social participation, with potentially lifelong consequences for educational and occupational outcomes. While most speech errors resolve by the late school-age years, between 2 and 5% of speakers exhibit residual speech errors (RSE) that persist through adolescence or even adulthood. Previous findings from small-scale studies suggest that interventions incorporating visual biofeedback can outperform traditional motor-based treatment approaches for children with RSE, but this question has not been investigated in a well-powered randomized controlled trial.

Methods/design

This project, Correcting Residual Errors with Spectral, ULtrasound, Traditional Speech therapy Randomized Controlled Trial (C-RESULTS RCT), aims to treat 110 children in a parallel randomized controlled clinical trial comparing biofeedback and non-biofeedback interventions for RSE affecting the North American English rhotic sound /ɹ/. Eligible children will be American English speakers, aged 9–15 years, who exhibit RSE affecting /ɹ/ but otherwise show typical cognitive-linguistic and hearing abilities. Participants will be randomized, with stratification by site (Syracuse University or Montclair State University) and pre-treatment speech production ability, to receive either a motor-based treatment consistent with current best practices in speech therapy (40% of participants) or treatment incorporating visual biofeedback (60% of participants). Within the biofeedback condition, participants will be assigned in equal numbers to receive biofeedback in the form of a real-time visual display of the acoustic signal of speech or ultrasound imaging of the tongue during speech. The primary outcome measure will assess changes in the acoustics of children’s production of /ɹ/ during treatment, while a secondary outcome measure will use blinded listeners to evaluate changes in the perceived accuracy of /ɹ/ production after the completion of all treatment. These measures will allow the treatment conditions to be compared with respect to both efficacy and efficiency.

Discussion

By conducting the first well-powered randomized controlled trial comparing treatment with and without biofeedback, this study aims to provide high-quality evidence to guide treatment decisions for children with RSE.

Trial registration

ClinicalTrials.gov identifier NCT03737318, November 9, 2018.

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.