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

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.

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.

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

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

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.

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

PURPOSE

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

A Qualitative Analysis of Clinician Perspectives of Ultrasound Biofeedback for Speech Sound Disorders

PURPOSE

Ultrasound biofeedback therapy (UBT) is a relatively new type of technology-assisted speech-language therapy and has shown promise in remediating speech sound disorders. However, there is a current lack of understanding of the barriers and benefits that may influence the usage behavior and clinical decision making for the implementation of UBT from a clinician perspective. In this qualitative study, we explore the perspectives of speech-language pathologists (SLPs) who have used ultrasound biofeedback in programs of speech sound therapy using the unified theory of acceptance and use of technology (UTAUT) model.

METHOD

Seven SLPs who had clinical experience treating speech sound disorders with UBT participated. Semistructured in-depth interviews were conducted and video-recorded. Two coders coded and categorized the transcribed data, with consensus established with a third coder. Using thematic analysis, the data were exploratorily grouped into themes along components of the UTAUT model.

RESULTS

The highest number of codes was sorted into the "effort expectancy" theme, followed by "performance expectancy," "social influence," and "facilitating conditions" themes of the UTAUT model. Clinicians identified multiple perceived barriers and benefits to the use of ultrasound technology. The top identified barrier was limited accessibility, and the top benefit was the ability to visualize a client's articulatory response to cues on a display.

CONCLUSIONS

Clinicians prioritized "effort expectancy" and "performance expectancy" when reflecting on the use of ultrasound biofeedback for speech sound disorders. Clinicians spoke favorably about using UBT for speech sound disorder treatment but acknowledged institutional barriers and limitations at organizational and social levels.

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.

Phonetic versus spatial processes during motor-oriented imitations of visuo-labial and visuo-lingual speech: A functional near-infrared spectroscopy study

While a large amount of research has studied the facilitation of visual speech on auditory speech recognition, few have investigated the processing of visual speech gestures in motor-oriented tasks that focus on the spatial and motor features of the articulator actions instead of the phonetic features of auditory and visual speech. The current study examined the engagement of spatial and phonetic processing of visual speech in a motor-oriented speech imitation task. Functional near-infrared spectroscopy (fNIRS) was used to measure the haemodynamic activities related to spatial processing and audiovisual integration in the superior parietal lobe (SPL) and the posterior superior/middle temporal gyrus (pSTG/pMTG) respectively. In addition, visuo-labial and visuo-lingual speech were compared with examine the influence of visual familiarity and audiovisual association on the processes in question. fNIRS revealed significant activations in the SPL but found no supra-additive audiovisual activations in the pSTG/pMTG, suggesting that the processing of audiovisual speech stimuli was primarily focused on spatial processes related to action comprehension and preparation, whereas phonetic processes related to audiovisual integration was minimal. Comparisons between visuo-labial and visuo-lingual speech imitations revealed no significant difference in the activation of the SPL or the pSTG/pMTG, suggesting that a higher degree of visual familiarity and audiovisual association did not significantly influence how visuo-labial speech was processed compared with visuo-lingual speech. The current study offered insights on the pattern of visual-speech processing under a motor-oriented task objective and provided further evidence for the modulation of multimodal speech integration by voluntary selective attention and task objective.

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.

Autism-Centered Therapy for Childhood Apraxia of Speech (ACT4CAS): A Single-Case Experimental Design Study

Purpose A subset of children with autism spectrum disorder (ASD) has speech sound disorders, including childhood apraxia of speech (CAS). To date, virtually all speech treatment studies consider ASD an exclusionary criterion, resulting in little scientific evidence for treatment of CAS for children who also have ASD. This study proposes and tests a novel approach, Autism-Centered Therapy for Childhood Apraxia of Speech (ACT4CAS), as a theoretically and clinically informed speech treatment option for this population. Method Using a multiple-baseline design within and across participants, three children with co-occurring ASD and CAS received 11-18 treatment sessions. Treatment targets were individually designed and matched with untreated control words. Probes were administered at the start of each session to assess speech production accuracy perceptually. Changes in production accuracy were examined through visual inspection and quantified with effect sizes. Results Findings were mixed, with one child showing significant gains for half of the treated targets at follow-up and two children showing no clear improvement. Conclusions Preliminary evidence suggests potentially positive treatment effects for ACT4CAS when implemented as intended, although treatment intensity and disorder severity likely influence treatment outcome. Replication and comparison of ACT4CAS to other speech treatments is needed. Supplemental Material https://doi.org/10.23641/asha.14110445.

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.

Assessing Rhotic Production by Bilingual Spanish Speakers

Due to its articulatory precision, the Spanish rhotic system is generally acquired in late childhood by monolingually-raised (L1) Spanish speakers. Heritage speakers and second language (L2) learners, unlike L1 speakers, risk an incomplete acquisition of the rhotic system due to limited Spanish input and possible phonological interference from English. In order to examine the effects of age of onset of bilingualism and cross-linguistic influence on bilinguals’ rhotic productions, twenty-four adult participants (six sequential bilingual heritage speakers, six simultaneous bilingual heritage speakers, six L1 Spanish speakers, six L2 Spanish learners) were audio recorded in a storytelling task and a picture naming task. The alveolar taps [ɾ] and alveolar trills [r] produced in these tasks were examined according to duration of the rhotic sound and number of apical occlusions. Results showed that the sequential bilinguals, but not the simultaneous bilinguals or the L2 learners, patterned similarly to the L1 Spanish speakers in their production of taps and trills. Neither heritage group produced the English alveolar approximant [ɹ]; the L2 learners, on the other hand, did produce [ɹ] when speaking Spanish. The results of this study suggest that early language input can affect the production of sounds that are acquired in late childhood.

Effects of Practice Variability on Second-Language Speech Production Training

BACKGROUND

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

PARTICIPANTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Tutorial: Motor-Based Treatment Strategies for /r/ Distortions

Purpose This tutorial summarizes current best practices in treating American English /r/ distortions in children with residual speech errors. Method To enhance the effectiveness of clinicians' cueing and feedback, the phonetics of /r/ production is reviewed. Principles of acquisition, which can inform how to practice /r/ in the early stages of therapy, are explained. Elements of therapy that lack scientific support are also mentioned. Results Although there is significant variability in /r/ production, the common articulatory requirements include an oral constriction, a pharyngeal constriction, tongue body lowering, lateral bracing, and slight lip rounding. Examples of phonetic cues and shaping strategies are provided to help clinicians elicit these movements to evoke correct /r/ productions. Principles of acquisition (e.g., blocked practice, frequent knowledge of performance feedback) are reviewed to help clinicians structure the earliest stages of treatment to establish /r/. Examples of approaches that currently lack scientific support include nonspeech oral motor exercises, tactile cues along the mylohyoid muscle, and heterogeneous groupings in group therapy. Conclusion Treatment strategies informed by phonetic science and motor learning theory can be implemented by all clinicians to enhance acquisition of /r/ for children with residual errors. Supplemental Material https://doi.org/10.23641/asha.12771329.

Articulatory tongue shape analysis of Mandarin alveolar-retroflex contrast

As existing descriptions are likely too narrow to reflect a broader range of articulatory variability in Mandarin production, this study is undertaken to explore qualitative and quantitative tongue shape analysis in Mandarin sibilants. Tongue movement data are collected from 18 adult Mandarin speakers producing six sibilants in three vowel contexts. Acoustic information is also analyzed to establish the articulatory-acoustic correspondence. In addition to the common retroflex and bunched shapes, the results discovered a humped shape (e.g., a single, posterior lingual constriction) in most of Mandarin retroflex tokens. This shape is one variant of North American English /r/, but yet identified in Mandarin production. The humped shape adds to the literature and expands existing descriptions of Mandarin retroflex tongue configurations. Despite the shape differences, the general many-to-one articulatory-acoustic mappings also holds true for Mandarin retroflexes. However, while curvature analyses based on Cartesian coordinates significantly differentiated contrastive shapes in retroflex production, these analyses were not equally reliable in separating the alveolar-retroflex distinction, likely due to individual differences. The tongue contour changes in the place contrast were instead quantified by calculations with polar coordinates. The preliminary findings on Mandarin retroflexes are discussed in terms of vocal tract morphology, with possible lip protrusion.

Rehabilitation of speech disorders following glossectomy, based on ultrasound visual illustration and feedback

Intraoral surgery for tongue cancer usually induces speech disorders that have a negative impact on communication and quality of life. Studies have documented the benefit of tongue ultrasound imaging as a visual articulatory feedback for speech rehabilitation. This study aims to assess specifically the complementary contribution of visual feedback to visual illustration (i.e. the display of ultrasound video of target language movements) for the speech rehabilitation of glossectomised patients. Two therapy conditions were used alternately for ten glossectomised French patients randomly divided into two cohorts. The IF cohort benefitted from 10 sessions using illustration alone (IL condition) followed by 10 sessions using illustration supplemented by visual feedback (IL+F condition). The FI cohort followed the opposite protocol, i.e. the first 10 sessions with the IL+F condition, followed by 10 sessions with the IL condition. Phonetic accuracy (Percent Consonants Correct) was monitored at baseline (T0, before the first series) and after each series (T1 and T2) using clinical speech-language assessments. None of the contrasts computed between the two conditions, using logistic regression with random effects models, were found to be statistically significant for the group analysis of assessment scores. Results were significant for a few individuals, with balanced advantages in both conditions. In conclusion, the use of articulatory visual feedback does not seem to bring a decisive advantage over the use of visual illustration, though speech therapists and patients reported that ultrasound feedback was useful at the beginning. This result should be confirmed by similar studies involving other types of speech disorders.

Tongue Part Movement Trajectories for /r/ Using Ultrasound

Purpose

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

Method

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

Results

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

Conclusion

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

Auditory Perception and Ultrasound Biofeedback Treatment Outcomes for Children With Residual /ɹ/ Distortions: A Randomized Controlled Trial

Purpose This study evaluated whether outcomes from treatment, which includes ultrasound visual feedback (UVF), would be more or less effective when combined with auditory perception training for children with residual /ɹ/ errors. Method Children ages 8-16 years with /ɹ/ distortions participated in speech therapy that included real-time UVF of the tongue. Thirty-eight participants were randomized to speech therapy conditions that included a primary focus on articulation using UVF or a condition that included auditory perceptual training plus UVF (incorporating category goodness judgments and self-monitoring). Generalization of /ɹ/ production accuracy to untrained words was assessed before and after 14 hr of therapy. Additionally, the role of auditory perceptual acuity was explored using a synthetic /ɹ/-/w/ continuum. Results There was no difference between the treatment groups in rate of improvement of /ɹ/ accuracy (increase of 34% for each group; p = .95, ηp2 = .00). However, pretreatment auditory acuity was associated with treatment progress in both groups, with finer perceptual acuity corresponding to greater progress (p = .015, ηp2 = .182). Conclusion Similar gains in speech sound accuracy can be made with treatment that includes UVF with or without auditory perceptual training. Fine-grained perceptual acuity may be a prognostic indicator with treatment. Supplemental Material https://doi.org/10.23641/asha.11886219.

Acquired Apraxia of Speech: Comparison of Electropalatography Treatment and Sound Production Treatment

Purpose This investigation compared 2 treatment approaches for acquired apraxia of speech. The effects of a treatment that uses an articulatory-kinematic approach in conjunction with visual biofeedback (VBFB) via electropalatography (EPG) were compared to Sound Production Treatment (SPT), an established behavioral treatment that is also an articulatory-kinematic approach. Method A multiple baseline design across behaviors and participants was used with 2 participants with chronic apraxia of speech and aphasia. Accuracy of target speech sounds in treated and untreated words or phrases in probe sessions served as the dependent variable. The effects of 2 treatments based on an articulatory-kinematic approach were compared: (a) VBFB via EPG and (b) SPT. The order of treatments was counterbalanced across participants. Results Positive changes in articulatory accuracy were observed for SPT and VBFB treatment via EPG. Generalization to untreated stimulus items composed of treated speech sounds was also positive for both treatments. However, participants achieved greater articulatory accuracy with SPT during treatment and better long-term maintenance. Discussion Both treatment approaches resulted in improved speech production accuracy, but gains were greater for SPT. However, further research with additional participants is needed due to the small sample size included in this investigation.

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.

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

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

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

BACKGROUND

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

AIMS

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

METHODS

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

MAIN CONTRIBUTIONS

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

CONCLUSIONS

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

Three-/Four-Dimensional Ultrasound Technology in Speech Research

Purpose

Speech production is a complex 3-dimensional (3D) process, and yet most of what is known about it is derived from 2D midsagittal data. The relatively recent development of safe 3D imaging technologies (including magnetic resonance imaging and ultrasound) provide new opportunities to revisit and reformulate what is already known and to push the boundaries of current knowledge still further. A particularly useful imaging modality for this purpose is 3D/4D ultrasound, which until very recently was not well suited for studies in speech research. This technical report presents an overview of what 3D/4D ultrasound can contribute to speech research, with a focus on 2 demonstrations.

Conclusion

The 1st demonstration illustrates how 3D/4D ultrasound makes it possible to image certain vocal tract anatomical structures and planes that conventional 2D ultrasound is not capable of imaging. The 2nd demonstration illustrates how 3D/4D ultrasound can be combined with static 3D magnetic resonance imaging to provide new insight into the temporal pervasiveness and spatial extensiveness of lateral contact between the tongue and palate–teeth during speech production.

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.

Rhotic vowel accuracy and error patterns in young children with and without Speech Sound Disorders

Rhotic vowels are known to be difficult sounds for children to learn, but their acquisition has not been investigated in detail. This study examined rhotic vowel development, including accuracy and error patterns, in young children across age, diagnostic groups, and phonetic contexts. Participants included 34 children from 2 to 6 years of age with and without speech sound disorders (SSD). Data included 36 elicited single words containing stressed and unstressed rhotic monophthongs ([ɜ˞] and [ə˞]) and four rhotic diphthongs (/ɪ͡ə˞/, /ε͡ə˞/, /ɔ͡ə˞/, and /ɑ͡ə˞/). Additional words containing non-rhotic vowels and the consonant /ɹ/ were also included for comparison. A significant difference in rhotic vowel production accuracy was found between diagnostic groups (with vs. without SSD), but not across age groups or phonetic contexts. Yet, the accuracy scores for children without SSD were bimodally distributed, showing overlapping patterns with children with SSD. Error patterns were examined for all children with low rhotic vowel accuracy scores, regardless of age and diagnostic status. Results of this study highlight the variability in rhotic vowel development in young children and the importance of studying rhotic sounds using overall rhotic sound accuracy of each individual child regardless of their age or diagnostic status. Clinically, systematic within-speaker error patterns suggest the need for the detailed error pattern assessment of rhotic sounds.

Selecting an acoustic correlate for automated measurement of American English rhotic production in children

Purpose: A current need in the field of speech-language pathology is the development of reliable and efficient techniques to evaluate accuracy of speech targets over the course of treatment. As acoustic measurement techniques improve, it should become possible to use automated scoring in lieu of ratings from a trained clinician in some contexts. This study asks which acoustic measures correspond most closely with expert ratings of children's productions of American English /ɹ/ in an effort to develop an automated scoring algorithm for use in treatment targeting rhotics. Method: A series of ordinal mixed-effects regression models were fit over a large sample of children's productions of words containing /ɹ/ that had previously been rated by three trained clinicians. Akaike/Bayesian Information Criteria were used to select the best-fitting model. Result: Controlling for age, sex, and allophonic contextual differences, the measure that accounted for the most variance in speech rating was F3-F2 distance normalised relative to a sample of age- and sex-matched speakers. Conclusion: We recommend this acoustic measure for use in future automated scoring of children's production of American English rhotics. We also suggest that computer-based treatment with automated scoring should facilitate increases in treatment dosage by improving options for home practice.

Telling Apart Motor Noise and Exploratory Behavior, in Early Development

Infants' minutes long babbling bouts or repetitive reaching for or mouthing of whatever they can get their hands on gives very much the impression of active exploration, a building block for early learning. But how can we tell apart active exploration from the activity of an immature motor system, attempting but failing to achieve goal directed behavior? I will focus here on evidence that infants increase motor activity and variability when faced with opportunities to gather new information (about their own bodies or the world) and propose this as a guiding principle for separating variability generated for exploration from noise. I will discuss mechanisms generating movement variability, and suggests that, in the various forms it takes, from deliberate hypothesis testing to increasing environmental variability, it could be exploited for learning. However, understanding how variability in motor acts contributes to early learning will require more in-depth investigations of both the nature of and the contextual modulation of this variability.

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.

Do Participants Report Any Undesired Effects in Ultrasound Speech Therapy?

Purpose

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

Method

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

Results

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

Conclusion

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

Preparation of a Protocol for Instrumental Assessment of Speech (PRAINF) based on psychometric and linguistic criteria

OBJECTIVE

Propose a protocol for instrumental assessment of adult speech considering psychometric and linguistic criteria.

METHODS

The choice of words was based on previously defined Brazilian Portuguese linguistic criteria after a search on the "Portal da Língua Portuguesa" database using the Portuguese Orthographic Vocabulary (VOP). The defined linguistic criteria considered grammatical class, vowel context, number of syllables, stress, and presence of words in the daily life of Brazilian adults. The choice of the images to represent the words considered the criteria of imageability, clearness, and cultural aspects. The words and images were rigorously evaluated by 13 non-specialist judges and six specialist judges. After being examined by the judges, the words were tested in adults through instrumental assessment.

RESULTS

The protocol was composed of 19 words and images, with prevalence of nouns over adjectives. Each word included one target sound in Onset Medial position, in the context precedent and following the vowel [a], trisyllabic and paroxytone words. The adults that attended the instrumental assessments succeeded in producing the list of words spontaneously. The data obtained through the assessments provided adequate analysis.

CONCLUSION

This study provided additional information on psychometric and linguistic criteria in addition to providing a protocol for instrumental assessment of adult speech.

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

PURPOSE

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Intensive Treatment for Persisting Rhotic Distortions: A Case Series

PURPOSE

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

METHOD

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

RESULTS

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

CONCLUSION

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

SUPPLEMENTAL MATERIALS

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

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.

Variable Practice to Enhance Speech Learning in Ultrasound Biofeedback Treatment for Childhood Apraxia of Speech: A Single Case Experimental Study

PURPOSE

The purpose of this study was to evaluate the role of practice variability, through prosodic variation during speech sound training, in biofeedback treatment for children with childhood apraxia of speech. It was hypothesized that variable practice would facilitate speech sound learning.

METHOD

Six children ages 8-16 years with persisting speech sound errors due to childhood apraxia of speech participated in a single-subject experimental design. For each participant, 2 speech sound targets were treated with ultrasound visual feedback training: one with prosodic variation (i.e., practicing sound targets in words and phrases spoken fast, slow, loud, as a question, command, and declarative), and one without prosodic variation. Each target was treated for half of the 1-hr session for 14 treatment sessions.

RESULTS

As measured by standardized effect sizes, all participants showed greater change on generalization probes for sound targets treated under the prosodic variation condition with mean effect sizes (d2) of 14.5 for targets treated with prosodic variation and 8.3 for targets treated without prosodic variation. The average increase in generalization scores was 38% in the prosodic variation condition compared to 31% without.

CONCLUSIONS

Ultrasound visual feedback may facilitate speech sound learning and learning may be enhanced by treating speech sounds with explicit prosodic variation.

SUPPLEMENTAL MATERIALS

https://doi.org/10.23641/asha.5150119.

Deriving individualised /r/ targets from the acoustics of children's non-rhotic vowels

In visual-acoustic biofeedback for rhotic errors, learners are guided to match the third formant (F3) location to a visual target on a real-time acoustic spectrum. As the acoustic properties of correct English /r/differ across speakers, this study aimed to improve target selection by investigating the validity of individualised targets derived from children's non-rhotic vowels. A previously proposed prediction formula was adjusted using data from a child normative sample and tested in two groups of children. Study 1 found that predicted values were unexpectedly higher than actual F3 values in children whose /r/ errors had been remediated. To understand this discrepancy, Study 2 applied the formula to typically developing children and found that predicted values were also higher than actual F3 values, suggesting that different normative data might better represent the current samples. An updated formula is proposed, which can be used to generate individualised targets within acoustic biofeedback applications.

Enhancing Intervention for Residual Rhotic Errors Via App-Delivered Biofeedback: A Case Study

Purpose

Recent research suggests that visual-acoustic biofeedback can be an effective treatment for residual speech errors, but adoption remains limited due to barriers including high cost and lack of familiarity with the technology. This case study reports results from the first participant to complete a course of visual-acoustic biofeedback using a not-for-profit iOS app, Speech Therapist's App for /r/ Treatment.

Method

App-based biofeedback treatment for rhotic misarticulation was provided in weekly 30-min sessions for 20 weeks. Within-treatment progress was documented using clinician perceptual ratings and acoustic measures. Generalization gains were assessed using acoustic measures of word probes elicited during baseline, treatment, and maintenance sessions.

Results

Both clinician ratings and acoustic measures indicated that the participant significantly improved her rhotic production accuracy in trials elicited during treatment sessions. However, these gains did not transfer to generalization probes.

Conclusions

This study provides a proof-of-concept demonstration that app-based biofeedback is a viable alternative to costlier dedicated systems. Generalization of gains to contexts without biofeedback remains a challenge that requires further study. App-delivered biofeedback could enable clinician-research partnerships that would strengthen the evidence base while providing enhanced treatment for children with residual rhotic errors.

Supplemental Material

https://doi.org/10.23641/asha.5116318.

Masked Visual Analysis: Minimizing Type I Error in Visually Guided Single-Case Design for Communication Disorders

PURPOSE

Single-case experimental designs are widely used to study interventions for communication disorders. Traditionally, single-case experiments follow a response-guided approach, where design decisions during the study are based on participants' observed patterns of behavior. However, this approach has been criticized for its high rate of Type I error. In masked visual analysis (MVA), response-guided decisions are made by a researcher who is blinded to participants' identities and treatment assignments. MVA also makes it possible to conduct a hypothesis test assessing the significance of treatment effects.

METHOD

This tutorial describes the principles of MVA, including both how experiments can be set up and how results can be used for hypothesis testing. We then report a case study showing how MVA was deployed in a multiple-baseline across-subjects study investigating treatment for residual errors affecting rhotics. Strengths and weaknesses of MVA are discussed.

CONCLUSIONS

Given their important role in the evidence base that informs clinical decision making, it is critical for single-case experimental studies to be conducted in a way that allows researchers to draw valid inferences. As a method that can increase the rigor of single-case studies while preserving the benefits of a response-guided approach, MVA warrants expanded attention from researchers in communication disorders.

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.

Ultrasound Images of the Tongue: A Tutorial for Assessment and Remediation of Speech Sound Errors

Diagnostic ultrasound imaging has been a common tool in medical practice for several decades. It provides a safe and effective method for imaging structures internal to the body. There has been a recent increase in the use of ultrasound technology to visualize the shape and movements of the tongue during speech, both in typical speakers and in clinical populations. Ultrasound imaging of speech has greatly expanded our understanding of how sounds articulated with the tongue (lingual sounds) are produced. Such information can be particularly valuable for speech-language pathologists. Among other advantages, ultrasound images can be used during speech therapy to provide (1) illustrative models of typical (i.e. "correct") tongue configurations for speech sounds, and (2) a source of insight into the articulatory nature of deviant productions. The images can also be used as an additional source of feedback for clinical populations learning to distinguish their better productions from their incorrect productions, en route to establishing more effective articulatory habits. Ultrasound feedback is increasingly used by scientists and clinicians as both the expertise of the users increases and as the expense of the equipment declines. In this tutorial, procedures are presented for collecting ultrasound images of the tongue in a clinical context. We illustrate these procedures in an extended example featuring one common error sound, American English /r/. Images of correct and distorted /r/ are used to demonstrate (1) how to interpret ultrasound images, (2) how to assess tongue shape during production of speech sounds, (3), how to categorize tongue shape errors, and (4), how to provide visual feedback to elicit a more appropriate and functional tongue shape. We present a sample protocol for using real-time ultrasound images of the tongue for visual feedback to remediate speech sound errors. Additionally, example data are shown to illustrate outcomes with the procedure.

Motor-based treatment with and without ultrasound feedback for residual speech-sound errors

BACKGROUND

There is a need to develop effective interventions and to compare the efficacy of different interventions for children with residual speech-sound errors (RSSEs). Rhotics (the r-family of sounds) are frequently in error American English-speaking children with RSSEs and are commonly targeted in treatment. One treatment approach involves the use of ultrasound visual feedback of the tongue.

AIMS

Although prior studies have shown that children with RSSEs acquire rhotics and generalize to untrained words with ultrasound visual feedback treatment, predictions from schema-based motor learning theory suggest that visual feedback might impede generalization. Therefore, the primary aim was to compare the generalization of rhotics treated with and without ultrasound in children with RSSEs.

METHODS & PROCEDURES

Twelve children aged 10-16 years with RSSEs affecting rhotics participated in a multiple-baseline single-case design with two treatment phases. For each participant, rhotics in one syllable position were treated for 7 h-long sessions with ultrasound visual feedback and rhotics in a different syllable position were treated without ultrasound in a second treatment phase. The order of treatment conditions was counterbalanced across participants. A treatment framework incorporating the principles of motor learning through chaining procedures was implemented across both treatment phases; thus the primary distinction between conditions was the use of ultrasound visual feedback.

OUTCOMES & RESULTS

On average, both treatments resulted in an approximately 30% increase in accuracy of untreated words in seven sessions. However, variability in response suggested some children showed a preferential response to one treatment over another, some responded well to both interventions, and some responded minimally to both interventions.

CONCLUSIONS & IMPLICATIONS

Motor-based treatment with and without ultrasound visual feedback of the tongue may aid in speech-sound acquisition for children with RSSEs. Both approaches may be viable options for some children. Future research is necessary to determine which children are the best candidates for interventions with and without ultrasound visual feedback.

The Use of Electropalatography in the Treatment of Acquired Apraxia of Speech

PURPOSE

This investigation was designed to examine the effects of an articulatory-kinematic treatment in conjunction with visual biofeedback (VBFB) via electropalatography (EPG) on the accuracy of articulation for acquired apraxia of speech (AOS).

METHOD

A multiple-baseline design across participants and behaviors was used with 4 individuals with chronic AOS and aphasia. Accuracy of target speech sounds in treated and untreated phrases in probe sessions served as the dependent variable. Participants received an articulatory-kinematic treatment in combination with VBFB, which was sequentially applied to 3 stimulus sets composed of 2-word phrases with a target speech sound for each set.

RESULTS

Positive changes in articulatory accuracy were observed for participants for the majority of treated speech sounds. Also, there was generalization to untreated phrases for most trained speech sounds. Two participants had better long-term maintenance of treated speech sounds in both trained and untrained stimuli.

CONCLUSIONS

Findings indicate EPG may be a potential treatment tool for AOS. It appears that individuals with AOS can benefit from VBFB via EPG in improving articulatory accuracy. However, further research is needed to determine if VBFB is more advantageous than behavioral treatments that have been proven effective in improving speech production for speakers with AOS.

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.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

Ultrasound imaging is an adjunct to traditional speech therapy that has shown to be beneficial in the remediation of speech sound errors. Ultrasound biofeedback can be utilized during therapy to provide clients with additional knowledge about their tongue shapes when attempting to produce sounds that are erroneous. The additional feedback may assist children with childhood apraxia of speech (CAS) in stabilizing motor patterns, thereby facilitating more consistent and accurate productions of sounds and syllables. However, due to its specialized nature, ultrasound visual feedback is a technology that is not widely available to clients. Short-term intensive treatment programs are one option that can be utilized to expand access to ultrasound biofeedback. Schema-based motor learning theory suggests that short-term intensive treatment programs (massed practice) may assist children in acquiring more accurate motor patterns. In this case series, three participants ages 10–14 years diagnosed with CAS attended 16 h of speech therapy over a 2-week period to address residual speech sound errors. Two participants had distortions on rhotic sounds, while the third participant demonstrated lateralization of sibilant sounds. During therapy, cues were provided to assist participants in obtaining a tongue shape that facilitated a correct production of the erred sound. Additional practice without ultrasound was also included. Results suggested that all participants showed signs of acquisition of sounds in error. Generalization and retention results were mixed. One participant showed generalization and retention of sounds that were treated; one showed generalization but limited retention; and the third showed no evidence of generalization or retention. Individual characteristics that may facilitate generalization are discussed. Short-term intensive treatment programs using ultrasound biofeedback may result in the acquisition of more accurate motor patterns and improved articulation of sounds previously in error, with varying levels of generalization and retention.

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.