Revisiting Dysarthria Treatment Across Languages: The Hybrid Approach

Perceptual and acoustic predictors of speech intelligibility among Hebrew-speaking young adults with down syndrome

BACKGROUND

Down syndrome (DS) is a common chromosomal disorder associated with various speech impairments, including reduced intelligibility. While speech subsystem deficits in DS have been documented, their relative influence on intelligibility remains understudied, particularly in non-English speaking populations. This study investigated speech intelligibility and select subsystem functioning in Hebrew-speaking young adults with DS, aiming to describe the speech production disorder and identify predictors of single-word intelligibility in this population.

METHODS

Twenty-four adults with DS and 24 typically developing (TD) peers produced common single words in Hebrew. Perceptual and acoustic analyses were conducted on select speech subsystems, including articulatory (consonant and vowel production) and phonatory measures.

RESULTS

Speakers with DS had higher error rates for complex consonants and demonstrated vowel space centralization compared to TD peers. Group differences were observed in most acoustic vowel measures, with interactions with speaker gender, but only select acoustic voice measures. Stepwise regression analysis identified three significant predictors of single-word intelligibility in the DS group, namely Percentage of Consonants Correct (PCC), Jitter (ppq), and average ellipse size of vowel clusters within the acoustic vowel space.

CONCLUSIONS

These findings highlight the complex nature of speech intelligibility deficits in individuals with DS, emphasizing both articulatory and phonatory contributing factors. The results also suggest potential cross-linguistic differences in subsystem contributions to intelligibility. Clinical implications include the need for comprehensive assessment and targeted interventions addressing multiple speech subsystems in this population.

Speech and language biomarkers for Parkinson's disease prediction, early diagnosis and progression

Parkinson's disease (PD), a multifaceted neurodegenerative disorder, can manifest as an array of motor and non-motor symptoms. Among these, speech and language impairments are particularly prevalent, often preceding motor dysfunctions. Emerging research indicates that these impairments may serve as early disease indicators. In this narrative review, we synthesised current findings on the potential of speech and language symptoms in PD identification and progression monitoring. Our review highlights convergent, albeit preliminary, lines of evidence supporting the value of speech-related features in detecting early or prodromal PD, even across language groups, especially with sophisticated analytical techniques. Distinct speech patterns in PD subtypes and other neurological disorders may assist in differential diagnosis and inform targeted management efforts. These features also evolve over the disease course and could effectively be utilised for disease tracking and guide management plan modifications. Advances in digital voice processing allow cost-effective, remote and scalable monitoring for larger populations.

Introduction to the Forum: Native Language, Dialect, and Foreign Accent in Dysarthria

This timely collection is an international effort to serve as a foundation to encourage research that offers insights into the interaction between language variation and motor speech disorders. Specifically, this forum aimed to provide a platform that (a) explores and demonstrates the role of language variation in the manifestation of dysarthria, (b) considers language variation in clinical assessment and management, and (c) promotes awareness of diverse language backgrounds of people with dysarthria. The forum contains six articles, spanning a variety of research designs (cross-sectional, pre- and post-treatment), kinds of articles (tutorial, research article, commentary), and a range of languages from around the world (English, French, Korean Portuguese, Spanish).

Effects of Speech Cues on Acoustics and Intelligibility of Korean-Speaking Children With Cerebral Palsy

PURPOSE

Reduced speech intelligibility is often a hallmark of children with dysarthria secondary to cerebral palsy (CP), but effects of speech strategies for increasing intelligibility are understudied, especially in children who speak languages other than English. This study examined the effects of (the Korean translation of) two cues, "speak with your big mouth" and "speak with your strong voice," on speech acoustics and intelligibility of Korean-speaking children with CP.

METHOD

Fifteen Korean-speaking children with CP repeated words and sentences in habitual, big mouth, and strong voice conditions. Acoustic analyses were performed and intelligibility was assessed by means of 90 blinded listeners' ease-of-understanding (EoU) ratings and percentage of words correctly transcribed (PWC).

RESULTS

In response to both cues, children's vocal intensity and utterance duration increased significantly and differentially, whereas their vowel space area gains did not reach statistical significance. EoU increased significantly in the big mouth condition at word, but not sentence, level, whereas in the strong voice condition, EoU increased significantly at both levels. PWC increases were not statistically significant. Considerable variability in children's responses to cues was noted overall.

CONCLUSIONS

Korean-speaking children with CP modify their speech styles differentially when provided with cues aimed to increase their articulatory working space and vocal intensity. The results provide preliminary support for the use of the strong voice cue, in particular, to increase EoU. While the findings do not offer conclusive evidence of the intelligibility benefits of these cues, investigation with a larger sample size should provide further insight into optimal cueing strategies for increasing intelligibility in this population. Implications for language-specific versus language-independent treatment approaches are discussed.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25521052.

Do Acoustic Characteristics of Dysarthria in People With Parkinson's Disease Differ Across Languages?

PURPOSE

Cross-language studies suggest more similarities than differences in how dysarthria affects the speech of people with Parkinson's disease (PwPD) who speak different languages. In this study, we aimed to identify the relative contribution of acoustic variables to distinguish PwPD from controls who spoke varieties of two Romance languages, French and Portuguese.

METHOD

This bi-national, cross-sectional, and case-controlled study included 129 PwPD and 124 healthy controls who spoke French or Portuguese. All participants underwent the same clinical examinations, voice/speech recordings, and self-assessment questionnaires. PwPD were evaluated off and on optimal medication. Inferential analyses included Disease (controls vs. PwPD) and Language (French vs. Portuguese) as factors, and random decision forest algorithms identified relevant acoustic variables able to distinguish participants: (a) by language (French vs. Portuguese) and (b) by clinical status (PwPD on and off medication vs. controls).

RESULTS

French-speaking and Portuguese-speaking individuals were distinguished from each other with over 90% accuracy by five acoustic variables (the mean fundamental frequency and the shimmer of the sustained vowel /a/ production, the oral diadochokinesis performance index, the relative sound level pressure and the relative sound pressure level standard deviation of the text reading). A distinct set of parameters discriminated between controls and PwPD: for men, maximum phonation time and the oral diadochokinesis speech proportion were the most significant variables; for women, variables calculated from the oral diadochokinesis were the most discriminative.

CONCLUSIONS

Acoustic variables related to phonation and voice quality distinguished between speakers of the two languages. Variables related to pneumophonic coordination and articulation rate were the more effective in distinguishing PwPD from controls. Thus, our research findings support that respiration and diadochokinesis tasks appear to be the most appropriate to pinpoint signs of dysarthria, which are largely homogeneous and language-universal. In contrast, identifying language-specific variables with the speech tasks and acoustic variables studied was less conclusive.