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

Traditional and Visual-Acoustic Biofeedback Treatment via Telepractice for Residual Speech Sound Disorders Affecting /ɹ/: Pilot study

Purpose

This study aimed to examine the feasibility of telepractice delivery of a treatment package including visual-acoustic biofeedback and motor-based treatment for residual speech sound disorder affecting /ɹ/ in school-age children. The overall study used a single-case randomization design; however, this preliminary report will simply quantify changes in accuracy before and after completion of the treatment package. The present analysis did not differentiate between the relative contributions of biofeedback and motor-based treatments.

Method

Seven children aged 9-14 received speech therapy for /ɹ/ distortions via telepractice. The study design consisted of three phases: baseline (four sessions), treatment (20 sessions), and post-treatment (three sessions). Treatment included two sessions weekly for a duration of 10 weeks. The participants received one motor-based/non-biofeedback session and one visual-acoustic biofeedback session per week. The order of treatment within each week was randomly determined prior to the start of therapy. Overall progress was assessed using untrained listeners' ratings of word probes administered in the baseline and posttreatment phases.

Results

Findings revealed that six of the seven participants showed a clinically significant response to the overall treatment package, although the magnitude of individual responses varied across speech contexts (consonantal and vocalic) and participants.

Conclusion

The present results suggest that a treatment combining visual-acoustic biofeedback and motor-based treatment for residual /ɹ/ errors treatment can be effectively delivered via telepractice. Considerations for technology setup and treatment protocols are provided.

Preliminary Speech Perception Performance Profiles of School-Age Children With Childhood Apraxia of Speech, Speech Sound Disorder, and Typical Development

PURPOSE

Limited research exists assessing speech perception in school-age children with speech sound disorder (SSD) and childhood apraxia of speech (CAS); despite early evidence that speech perception may lead to error-prone motor planning/programming. In this study, we examine speech perception performance in school-age children with and without speech production deficits.

METHOD

Speech perception was assessed using the Wide Range Acoustic Accuracy Scale to determine the just-noticeable difference in discrimination for three consonant-vowel syllable contrasts (/bɑ/-/wɑ/, /dɑ/-/gɑ/, /ɹɑ/-/wɑ/), each varying along a single acoustic parameter for seven children with CAS with rhotic errors, seven children with SSD with rhotic errors, and seven typically developing (TD) children.

RESULTS

Findings revealed statistically significant mean differences between perceptual performance of children with CAS when compared to TD children for discrimination of /ɹɑ/-/wɑ/ contrasts. Large effect sizes were also observed for comparisons of /ɹɑ/-/wɑ/ contrasts between children with CAS, SSD, and TD peers. Additionally, large effect sizes were observed for /dɑ/-/gɑ/ contrasts between children with CAS and SSD and TD children despite nonsignificant mean differences in group performance.

CONCLUSIONS

Overall, mean outcome scores suggest that school-age children with CAS and persistent rhotic errors demonstrated less accurate speech perception skills relative to TD children for the /ɹɑ/-/wɑ/ contrasts. However, the relatively small sample sizes per group limit the extent to which these findings may be generalized to the broader population.

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.

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.

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.

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.

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.

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.

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.

Can perceptual training alter the effect of visual biofeedback in speech-motor learning?

Recent work showing that a period of perceptual training can modulate the magnitude of speech-motor learning in a perturbed auditory feedback task could inform clinical interventions or second-language training strategies. The present study investigated the influence of perceptual training on a clinically and pedagogically relevant task of vocally matching a visually presented speech target using visual-acoustic biofeedback. Forty female adults aged 18-35 yr received perceptual training targeting the English /æ-ɛ/ contrast, randomly assigned to a condition that shifted the perceptual boundary toward either /æ/ or /ɛ/. Participants were then asked to produce the word head while modifying their output to match a visually presented acoustic target corresponding with a slightly higher first formant (F1, closer to /æ/). By analogy to findings from previous research, it was predicted that individuals whose boundary was shifted toward /æ/ would also show a greater magnitude of change in the visual biofeedback task. After perceptual training, the groups showed the predicted difference in perceptual boundary location, but they did not differ in their performance on the biofeedback matching task. It is proposed that the explicit versus implicit nature of the tasks used might account for the difference between this study and previous findings.

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.

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.

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.

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.