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.

Tongue shapes for rhotics in school-age children with and without residual speech errors.

Speakers of North American English use variable tongue shapes for rhotic sounds. However, quantifying tongue shapes for rhotics can be challenging, and little is known about how tongue shape complexity corresponds to perceptual ratings of rhotic accuracy in children with residual speech sound errors (RSE). In this study, 16 children aged 9-16 with RSE and 14 children with typical speech (TS) development made multiple productions of 'Let Robby cross Church Street'. Midsagittal ultrasound images were collected once for children with TS and twice for children in the RSE group (once after 7 h of speech therapy, then again after another 7 h of therapy). Tongue contours for the rhotics in the four words were traced and quantified using a new metric of tongue shape complexity: the number of inflections. Rhotics were also scored for accuracy by four listeners. During the first assessment, children with RSE had fewer tongue inflections than children with TS. Following 7 h of therapy, there were increases in the number of inflections for the RSE group, with the cluster items cross and Street reaching tongue complexity levels of those with TS. Ratings of rhotic accuracy were correlated with the number of inflections. Therefore, the number of inflections in the tongue, an index of tongue shape complexity, was associated with perceived accuracy of rhotic productions.

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.

Compensations to auditory feedback perturbations in congenitally blind and sighted speakers: Acoustic and articulatory data.

This study investigated the effects of visual deprivation on the relationship between speech perception and production by examining compensatory responses to real-time perturbations in auditory feedback. Specifically, acoustic and articulatory data were recorded while sighted and congenitally blind French speakers produced several repetitions of the vowel /ø/. At the acoustic level, blind speakers produced larger compensatory responses to altered vowels than their sighted peers. At the articulatory level, blind speakers also produced larger displacements of the upper lip, the tongue tip, and the tongue dorsum in compensatory responses. These findings suggest that blind speakers tolerate less discrepancy between actual and expected auditory feedback than sighted speakers. The study also suggests that sighted speakers have acquired more constrained somatosensory goals through the influence of visual cues perceived in face-to-face conversation, leading them to tolerate less discrepancy between expected and altered articulatory positions compared to blind speakers and thus resulting in smaller observed compensatory responses.

Acoustic and articulatory analysis of French vowels produced by congenitally blind adults and sighted adults.

In a previous paper [Ménard et al., J. Acoust. Soc. Am. 126, 1406-1414 (2009)], it was demonstrated that, despite enhanced auditory discrimination abilities for synthesized vowels, blind adult French speakers produced vowels that were closer together in the acoustic space than those produced by sighted adult French speakers, suggesting finer control of speech production in the sighted speakers. The goal of the present study is to further investigate the articulatory effects of visual deprivation on vowels produced by 11 blind and 11 sighted adult French speakers. Synchronous ultrasound, acoustic, and video recordings of the participants articulating the ten French oral vowels were made. Results show that sighted speakers produce vowels that are spaced significantly farther apart in the acoustic vowel space than blind speakers. Furthermore, blind speakers use smaller differences in lip protrusion but larger differences in tongue position and shape than their sighted peers to produce rounding and place of articulation contrasts. Trade-offs between lip and tongue positions were examined. Results are discussed in the light of the perception-for-action control theory.

The influence of auditory acuity on acoustic variability and the use of motor equivalence during adaptation to a perturbation.

PURPOSE: The aim of this study was to relate speakers' auditory acuity for the sibilant contrast, their use of motor equivalent trading relationships in producing the sibilant /∫/, and their produced acoustic distance between the sibilants /s/ and /∫/. Specifically, the study tested the hypotheses that during adaptation to a perturbation of vocal-tract shape, high-acuity speakers use motor equivalence strategies to a greater extent than do low-acuity speakers in order to reach their smaller phonemic goal regions, and that high-acuity speakers produce greater acoustic distance between 2 sibilant phonemes than do low-acuity speakers. METHOD: Articulographic data from 7 German speakers adapting to a perturbation were analyzed for the use of motor equivalence. The speakers' produced acoustic distance between /s/ and /∫/ was calculated. Auditory acuity was assessed for the same speakers. RESULTS: High-acuity speakers used motor equivalence to a greater extent when adapting to a perturbation than did low-acuity speakers. Additionally, high-acuity speakers produced greater acoustic contrasts than did low-acuity-speakers. It was observed that speech rate had an influence on the use of motor equivalence: Slow speakers used motor equivalence to a lesser degree than did fast speakers. CONCLUSION: These results provide support for the mutual interdependence of speech perception and production.