Comparing online versus laboratory measures of speech perception in older children and adolescents.

Given the increasing prevalence of online data collection, it is important to know how behavioral data obtained online compare to samples collected in the laboratory. This study compares online and in-person measurement of speech perception in older children and adolescents. Speech perception is important for assessment and treatment planning in speech-language pathology; we focus on the American English /ɹ/ sound because of its frequency as a clinical target. Two speech perception tasks were adapted for web presentation using Gorilla: identification of items along a synthetic continuum from rake to wake, and category goodness judgment of English /ɹ/ sounds in words produced by various talkers with and without speech sound disorder. Fifty typical children aged 9-15 completed these tasks online using a standard headset. These data were compared to a previous sample of 98 typical children aged 9-15 who completed the same tasks in the lab setting. For the identification task, participants exhibited smaller boundary widths (suggestive of more acute perception) in the in-person setting relative to the online setting. For the category goodness judgment task, there was no statistically significant effect of modality. The correlation between scores on the two tasks was significant in the online setting but not in the in-person setting, but the difference in correlation strength was not statistically significant. Overall, our findings agree with previous research in suggesting that online and in-person data collection do not yield identical results, but the two contexts tend to support the same broad conclusions. In addition, these results suggest that online data collection can make it easier for researchers connect with a more representative sample of participants.

Evaluating acoustic representations and normalization for rhoticity classification in children with speech sound disorders.

The effects of different acoustic representations and normalizations were compared for classifiers predicting perception of children's rhotic versus derhotic /ɹ/. Formant and Mel frequency cepstral coefficient (MFCC) representations for 350 speakers were z-standardized, either relative to values in the same utterance or age-and-sex data for typical /ɹ/. Statistical modeling indicated age-and-sex normalization significantly increased classifier performances. Clinically interpretable formants performed similarly to MFCCs and were endorsed for deep neural network engineering, achieving mean test-participant-specific F1-score = 0.81 after personalization and replication (σx = 0.10, med = 0.83, n = 48). Shapley additive explanations analysis indicated the third formant most influenced fully rhotic predictions.

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.

Reproducible Speech Research With the Artificial Intelligence-Ready PERCEPT Corpora.

BACKGROUND: Publicly available speech corpora facilitate reproducible research by providing open-access data for participants who have consented/assented to data sharing among different research teams. Such corpora can also support clinical education, including perceptual training and training in the use of speech analysis tools. PURPOSE: In this research note, we introduce the PERCEPT (Perceptual Error Rating for the Clinical Evaluation of Phonetic Targets) corpora, PERCEPT-R (Rhotics) and PERCEPT-GFTA (Goldman-Fristoe Test of Articulation), which together contain over 36 hr of speech audio (> 125,000 syllable, word, and phrase utterances) from children, adolescents, and young adults aged 6-24 years with speech sound disorder (primarily residual speech sound disorders impacting /ɹ/) and age-matched peers. We highlight PhonBank as the repository for the corpora and demonstrate use of the associated speech analysis software, Phon, to query PERCEPT-R. A worked example of research with PERCEPT-R, suitable for clinical education and research training, is included as an appendix. Support for end users and information/descriptive statistics for future releases of the PERCEPT corpora can be found in a dedicated Slack channel. Finally, we discuss the potential for PERCEPT corpora to support the training of artificial intelligence clinical speech technology appropriate for use with children with speech sound disorders, the development of which has historically been constrained by the limited representation of either children or individuals with speech impairments in publicly available training corpora. CONCLUSIONS: We demonstrate the use of PERCEPT corpora, PhonBank, and Phon for clinical training and research questions appropriate to child citation speech. Increased use of these tools has the potential to enhance reproducibility in the study of speech development and disorders.

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

PURPOSE: Limited research has examined the suitability of crowdsourced ratings to measure treatment effects in speakers with Parkinson's disease (PD), particularly for constructs such as voice quality. This study obtained measures of reliability and validity for crowdsourced listeners' ratings of voice quality in speech samples from a published study. We also investigated whether aggregated listener ratings would replicate the original study's findings of treatment effects based on the Acoustic Voice Quality Index (AVQI) measure. METHOD: This study reports a secondary outcome measure of a randomized controlled trial with speakers with dysarthria associated with PD, including two active comparators (Lee Silverman Voice Treatment [LSVT LOUD] and LSVT ARTIC), an inactive comparator (untreated PD), and a healthy control group. Speech samples from three time points (pretreatment, posttreatment, and 6-month follow-up) were presented in random order for rating as "typical" or "atypical" with respect to voice quality. Untrained listeners were recruited through the Amazon Mechanical Turk crowdsourcing platform until each sample had at least 25 ratings. RESULTS: Intrarater reliability for tokens presented repeatedly was substantial (Cohen's κ = .65-.70), and interrater agreement significantly exceeded chance level. There was a significant correlation of moderate magnitude between the AVQI and the proportion of listeners classifying a given sample as "typical." Consistent with the original study, we found a significant interaction between group and time point, with the LSVT LOUD group alone showing significantly higher perceptually rated voice quality at posttreatment and follow-up relative to the pretreatment time point. CONCLUSIONS: These results suggest that crowdsourcing can be a valid means to evaluate clinical speech samples, even for less familiar constructs such as voice quality. The findings also replicate the results of the study by Moya-Galé et al. (2022) and support their functional relevance by demonstrating that the effects of treatment measured acoustically in that study are perceptually apparent to everyday listeners.

Auditory and Somatosensory Development for Speech in Later Childhood.

PURPOSE: This study collected measures of auditory-perceptual and oral somatosensory acuity in typically developing children and adolescents aged 9-15 years. We aimed to establish reference data that can be used as a point of comparison for individuals with residual speech sound disorder (RSSD), especially for RSSD affecting American English rhotics. We examined concurrent validity between tasks and hypothesized that performance on at least some tasks would show a significant association with age, reflecting ongoing refinement of sensory function in later childhood. We also tested for an inverse relationship between performance on auditory and somatosensory tasks, which would support the hypothesis of a trade-off between sensory domains. METHOD: Ninety-eight children completed three auditory-perceptual tasks (identification and discrimination of stimuli from a "rake"-"wake" continuum and category goodness judgment for naturally produced words containing rhotics) and three oral somatosensory tasks (bite block with auditory masking, oral stereognosis, and articulatory awareness, which involved explicit judgments of relative tongue position for different speech sounds). Pairwise associations were examined between tasks within each domain and between task performance and age. Composite measures of auditory-perceptual and somatosensory functions were used to investigate the possibility of a sensory trade-off. RESULTS: Statistically significant associations were observed between the identification and discrimination tasks and the bite block and articulatory awareness tasks. In addition, significant associations with age were found for the category goodness and bite block tasks. There was no statistically significant evidence of a trade-off between auditory-perceptual and somatosensory domains. CONCLUSIONS: This study provided a multidimensional characterization of speech-related sensory function in older children/adolescents. Complete materials to administer all experimental tasks have been shared, along with measures of central tendency and dispersion for scores in two subgroups of age. Ultimately, we hope to apply this information to make customized treatment recommendations for children with RSSD based on sensory profiles.

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.

Comparing metrics for quantification of children's tongue shape complexity using ultrasound imaging.

Speech sound disorders can pose a challenge to communication in children that may persist into adulthood. As some speech sounds are known to require differential control of anterior versus posterior regions of the tongue body, valid measurement of the degree of differentiation of a given tongue shape has the potential to shed light on development of motor skill in typical and disordered speakers. The current study sought to compare the success of multiple techniques in quantifying tongue shape complexity as an index of degree of lingual differentiation in child and adult speakers. Using a pre-existing data set of ultrasound images of tongue shapes from adult speakers producing a variety of phonemes, we compared the extent to which three metrics of tongue shape complexity differed across phonemes/phoneme classes that were expected to differ in articulatory complexity. We then repeated this process with ultrasound tongue shapes produced by a sample of young children. The results of these comparisons suggested that a modified curvature index and a metric representing the number of inflection points best reflected small changes in tongue shapes across individuals differing in vocal tract size. Ultimately, these metrics have the potential to reveal delays in motor skill in young children, which could inform assessment procedures and treatment decisions for children with speech delays and disorders.

Variability, accuracy, and cross-linguistic transfer in bilingual children speaking Jamaican Creole and English.

Due to the lack of normative data about bilingual speech development and limited availability of diagnostic tools optimised for this population, bilingual children under consideration for speech-language services are at an elevated risk of misdiagnosis. In the absence of validated assessment tools, speech-language pathologists may use measures of accuracy and variability of speech production to diagnose suspected speech sound disorders in bilingual children. Research in general motor development suggests that variability and accuracy may trade off in the course of maturation, whereby movement variability spikes before the transition to a more mature stage of motor control. Such variability-accuracy tradeoffs have been described in monolingual speech development but are understudied in bilingual populations, where cross-linguistic transfer occurs. This study aimed to examine variability, accuracy, and cross-linguistic transfer in the speech of 20 bilingual children speaking Jamaican Creole and English. We hypothesised that children who showed higher accuracy in their productions would also exhibit more variable speech, indicating a variability-accuracy tradeoff. The Word Inconsistency Assessment from the Diagnostic Evaluation of Articulation and Phonology was administered to measure accuracy and variability in the English context, where misdiagnosis is likely to occur. Contrary to our hypothesis, we observed that individuals with higher accuracy tended to be less variable in their productions. Future research should examine longitudinal trajectories of accuracy and variability and consider a more culturally-appropriate definition of 'accuracy' in documenting bilingual speech sound development.

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.

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.

Characterizing sensorimotor profiles in children with residual speech sound disorder: a pilot study.

PURPOSE: Children with speech errors who have reduced motor skill may be more likely to develop residual errors associated with lifelong challenges. Drawing on models of speech production that highlight the role of somatosensory acuity in updating motor plans, this pilot study explored the relationship between motor skill and speech accuracy, and between somatosensory acuity and motor skill in children. Understanding the connections among sensorimotor measures and speech outcomes may offer insight into how somatosensation and motor skill cooperate during speech production, which could inform treatment decisions for this population. METHOD: Twenty-five children (ages 9-14) produced syllables in an /ɹ/ stimulability task before and after an ultrasound biofeedback treatment program targeting rhotics. We first tested whether motor skill (as measured by two ultrasound-based metrics of tongue shape complexity) predicted acoustically measured accuracy (the normalized difference between the second and third formant frequencies). We then tested whether somatosensory acuity (as measured by an oral stereognosis task) predicted motor skill, while controlling for auditory acuity. RESULTS: One measure of tongue shape complexity was a significant predictor of accuracy, such that higher tongue shape complexity was associated with lower accuracy at pre-treatment but higher accuracy at post-treatment. Based on the same measure, children with better somatosensory acuity produced /ɹ/ tongue shapes that were more complex, but this relationship was only present at post-treatment. CONCLUSION: The predicted relationships among somatosensory acuity, motor skill, and acoustically measured /ɹ/ production accuracy were observed after treatment, but unexpectedly did not hold before treatment. The surprising finding that greater tongue shape complexity was associated with lower accuracy at pre-treatment highlights the importance of evaluating tongue shape patterns (e.g., using ultrasound) prior to treatment, and has the potential to suggest that children with high tongue shape complexity at pre-treatment may be good candidates for ultrasound-based treatment.

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

PURPOSE: Although mobile apps are used extensively by speech-language pathologists, evidence for app-based treatments remains limited in quantity and quality. This study investigated the efficacy of app-based visual-acoustic biofeedback relative to nonbiofeedback treatment using a single-case randomization design. Because of COVID-19, all intervention was delivered via telepractice. METHOD: Participants were four children aged 9-10 years with residual errors affecting American English /ɹ/. Using a randomization design, individual sessions were randomly assigned to feature practice with or without biofeedback, all delivered using the speech app Speech Therapist's App for /r/ Treatment. Progress was assessed using blinded listener ratings of word probes administered at baseline, posttreatment, and immediately before and after each treatment session. RESULTS: All participants showed a clinically significant response to the overall treatment package, with effect sizes ranging from moderate to very large. One participant showed a significant advantage for biofeedback over nonbiofeedback treatment, although the order of treatment delivery poses a potential confound for interpretation in this case. CONCLUSIONS: While larger scale studies are needed, these results suggest that app-based treatment for residual errors can be effective when delivered via telepractice. These results are compatible with previous findings in the motor learning literature regarding the importance of treatment dose and the timing of feedback conditions. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.18461576.

Sweat Equity: Student Scholarships in Aotearoa New Zealand's Universities.

This paper responds to calls from past and present students to increase the value of postgraduate scholarships in Aotearoa New Zealand. Here we provide context for understanding the scholarship landscape in Aotearoa, including how scholarships are understood in relation to dominant neoliberal framings of higher education and persistent inequities within the sector. We present data which provides insight into the current inequities in Summer, Masters and PhD scholarship values. The average value of PhD scholarships has remained stagnant between 2011 and 2019 resulting in the average being $11,238 less than the Living Wage in 2019. We show that the average length of time full-time PhD students take to complete their doctorates exceeds the three-year tenure of scholarships. We argue the status-quo of low scholarships, supplemented by postgraduate 'sweat', excludes people from participating in postgraduate education, preventing them and their communities from realising the public benefits that such an education can produce. We suggest that these inadequacies could be addressed through (1) raising Summer, Masters and PhD scholarships to the living wage; (2) extending tenure of PhD scholarships; and (3) reinstating the postgraduate student allowance. Supplementary Information: The online version contains supplementary material available at 10.1007/s40841-022-00244-5.

Teeth are for chewing: a critical review of the conceptualisation and ethics of a controversial intraoral weight-loss device.

We are a diverse collective of researchers who are committed to improving the health and wellbeing of marginalised individuals. This article is a response to, and critique of, the DentalSlim Diet Control research. This device revises a controversial 1970s weight-loss technology connected to poor health outcomes, which is indicative of a culture that consistently promotes harm to fat and other marginalised communities.We address the historical context in which unruly bodies, particularly fat, and Indigenous bodies have been the site of unethical investigation conducted under the auspices of medical research. Existence outside the normative white, male, cis physical ideal demands regulation, and disciplinary measures. We demonstrate how Brunton et al.'s research is underpinned by anti-fat attitudes and assumptions which impose this punitive physical intervention onto healthy people in a way that should not be acceptable in medical research.Further, we address a range of harms, giving attention to Maori and to individuals with eating disorders, along with issues of research integrity. We argue that no ethics committee should have approved this research, no academic journal should have published it, and no member of the dental and medical community should promote or prescribe this device.

Toward an index of oral somatosensory acuity: Comparison of three measures in adults.

PURPOSE: Somatosensory targets and feedback are instrumental in ensuring accurate speech production. Individuals differ in their ability to access and respond to somatosensory information, but there is no established standard for measuring somatosensory acuity. The primary objective of this study was to determine which of three measures of somatosensory acuity had the strongest association with change in production accuracy in a vowel learning task, while controlling for the better-studied covariate of auditory acuity. METHOD: Three somatosensory tasks were administered to 20 female college students: an oral stereognosis task, a bite block task with auditory masking, and a novel phonetic awareness task. Individual scores from the tasks were compared to their performance on a speech learning task in which participants were trained to produce novel Mandarin vowels with visual biofeedback. RESULTS: Of the three tasks, only bite block adaptation with auditory masking was significantly associated with performance in the speech learning task. Participants with weaker somatosensory acuity tended to demonstrate larger increases in production accuracy over the course of training. CONCLUSIONS: The bite block adaptation task measures proprioceptive awareness rather than tactile acuity and assesses somatosensory knowledge implicitly, with limited metalinguistic demands. This small-scale study provides preliminary evidence that these characteristics may be desirable for the assessment of oral somatosensory acuity, at least in the context of vowel learning tasks. Well-normed somatosensory measures could be of clinical utility by informing diagnosis/prognosis and treatment planning.

Extending Ultrasound Tongue Shape Complexity Measures to Speech Development and Disorders.

Purpose Generalizations can be made about the order in which speech sounds are added to a child's phonemic inventory and the ways that child speech deviates from adult targets in a given language. Developmental and disordered speech patterns are presumed to reflect differences in both phonological knowledge and skilled motor control, but the relative contribution of motor control remains unknown. The ability to differentially control anterior versus posterior regions of the tongue increases with age, and thus, complexity of tongue shapes is believed to reflect an individual's capacity for skilled motor control of speech structures. Method The current study explored the relationship between tongue complexity and phonemic development in children (ages 4-6 years) with and without speech sound disorder producing various phonemes. Using established metrics of tongue complexity derived from ultrasound images, we tested whether tongue complexity incrementally increased with age in typical development, whether tongue complexity differed between children with and without speech sound disorder, and whether tongue complexity differed based on perceptually rated accuracy (correct vs. incorrect) for late-developing phonemes in both diagnostic groups. Results Contrary to hypothesis, age was not significantly associated with tongue complexity in our typical child sample, with the exception of one association between age and complexity of /t/ for one measure. Phoneme was a significant predictor of tongue complexity, and typically developing children had more complex tongue shapes for /ɹ/ than children with speech sound disorder. Those /ɹ/ tokens that were rated as perceptually correct had higher tongue complexity than the incorrect tokens, independent of diagnostic classification. Conclusions Quantification of tongue complexity can provide a window into articulatory patterns characterizing children's speech development, including differences that are perceptually covert. With the increasing availability of ultrasound imaging, these measures could help identify individuals with a prominent motor component to their speech sound disorder and could help match those individuals with a corresponding motor-based treatment approach. Supplemental Material https://doi.org/10.23641/asha.14880039.

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.

Examining the Relationship Between Speech Perception, Production Distinctness, and Production Variability.

Several studies have demonstrated that individuals' ability to perceive a speech sound contrast is related to the production of that contrast in their native language. The theoretical account for this relationship is that speech perception and production have a shared multimodal representation in relevant sensory spaces (e.g., auditory and somatosensory domains). This gives rise to a prediction that individuals with more narrowly defined targets will produce greater separation between contrasting sounds, as well as lower variability in the production of each sound. However, empirical studies that tested this hypothesis, particularly with regard to variability, have reported mixed outcomes. The current study investigates the relationship between perceptual ability and production ability, focusing on the auditory domain. We examined whether individuals' categorical labeling consistency for the American English /ε/-/æ/ contrast, measured using a perceptual identification task, is related to distance between the centroids of vowel categories in acoustic space (i.e., vowel contrast distance) and to two measures of production variability: the overall distribution of repeated tokens for the vowels (i.e., area of the ellipse) and the proportional within-trial decrease in variability as defined as the magnitude of self-correction to the initial acoustic variation of each token (i.e., centering ratio). No significant associations were found between categorical labeling consistency and vowel contrast distance, between categorical labeling consistency and area of the ellipse, or between categorical labeling consistency and centering ratio. These null results suggest that the perception-production relation may not be as robust as suggested by a widely adopted theoretical framing in terms of the size of auditory target regions. However, the present results may also be attributable to choices in implementation (e.g., the use of model talkers instead of continua derived from the participants' own productions) that should be subject to further investigation.