Range and Precision of Formant Movement in Pediatric Dysarthria

A Probe Study on Vocal Development in Two Infants at Risk for Cerebral Palsy

The present work examined canonical babbling ratios longitudinally as a measure of onset and consolidation of canonical babbling in two infants at risk of cerebral palsy (CP) between 5 and 16 months. Ten typically developing infants were included for comparison at 6, 9, 12, and 16-19 months. Canonical babbling ratios (CBRs) were calculated from 5-min segments, and follow-up diagnostic outcomes were collected between 24 and 33 months. The two infants at risk demonstrated low CBR growth trajectories compared to the typical infant group, and slightly different patterns of consolidation. The two infants at risk were later diagnosed with different levels of CP and speech impairment severity. All infants demonstrated greater variability than expected. Studying canonical babbling and other prelinguistic milestones in this population may inform our perspective of the involvement of the motor system in the vocal domain. Additional implications on the analysis of canonical babbling using all-day home recordings are discussed.

Speech treatment for Hebrew-speaking adolescents and young adults with developmental dysarthria: A comparison of mSIT and Beatalk

BACKGROUND

Individuals with developmental dysarthria typically demonstrate reduced functioning of one or more of the speech subsystems, which negatively impacts speech intelligibility and communication within social contexts. A few treatment approaches are available for improving speech production and intelligibility among individuals with developmental dysarthria. However, these approaches have only limited application and research findings among adolescents and young adults.

AIMS

To determine and compare the effectiveness of two treatment approaches, the modified Speech Intelligibility Treatment (mSIT) and the Beatalk technique, on speech production and intelligibility among Hebrew-speaking adolescents and young adults with developmental dysarthria.

METHODS & PROCEDURES

Two matched groups of adolescents and young adults with developmental dysarthria participated in the study. Each received one of the two treatments, mSIT or Beatalk, over the course of 9 weeks. Measures of speech intelligibility, articulatory accuracy, voice and vowel acoustics were assessed both pre- and post-treatment.

OUTCOMES & RESULTS

Both the mSIT and Beatalk groups demonstrated gains in at least some of the outcome measures. Participants in the mSIT group exhibited improvement in speech intelligibility and voice measures, while participants in the Beatalk group demonstrated increased articulatory accuracy and gains in voice measures from pre- to post-treatment. Significant increases were noted post-treatment for first formant values for select vowels.

CONCLUSIONS & IMPLICATIONS

Results of this preliminary study are promising for both treatment approaches. The differentiated results indicate their distinct application to speech intelligibility deficits. The current findings also hold clinical significance for treatment among adolescents and young adults with motor speech disorders and application for a language other than English.

WHAT THIS PAPER ADDS

What is already known on the subject Developmental dysarthria (e.g., secondary to cerebral palsy) is a motor speech disorder that negatively impacts speech intelligibility, and thus communication participation. Select treatment approaches are available with the aim of improving speech intelligibility in individuals with developmental dysarthria; however, these approaches are limited in number and have only seldomly been applied specifically to adolescents and young adults. What this paper adds to existing knowledge The current study presents preliminary data regarding two treatment approaches, the mSIT and Beatalk technique, administered to Hebrew-speaking adolescents and young adults with developmental dysarthria in a group setting. Results demonstrate the initial effectiveness of the treatment approaches, with different gains noted for each approach across speech and voice domains. What are the potential or actual clinical implications of this work? The findings add to the existing literature on potential treatment approaches aiming to improve speech production and intelligibility among individuals with developmental dysarthria. The presented approaches also show promise for group-based treatments as well as the potential for improvement among adolescents and young adults with motor speech disorders.

Intelligibility Across a Reading Passage: The Effect of Dysarthria and Cued Speaking Styles

OBJECTIVE

Reading a passage out loud is a commonly used task in the perceptual assessment of dysarthria. The extent to which perceptual characteristics remain unchanged or stable over the time course of a passage is largely unknown. This study investigated crowdsourced visual analogue scale (VAS) judgments of intelligibility across a reading passage as a function of cued speaking styles commonly used in treatment to maximize intelligibility.

PATIENTS AND METHOD

The Hunter passage was read aloud in habitual, slow, loud, and clear speaking styles by 16 speakers with Parkinson's disease (PD), 30 speakers with multiple sclerosis (MS), and 32 control speakers. VAS judgments of intelligibility from three fragments representing the beginning, middle, and end of the reading passage were obtained from 540 crowdsourced online listeners.

RESULTS

Overall passage intelligibility was reduced for the two clinical groups relative to the control group. All speaker groups exhibited intelligibility variation across the reading passage, with trends of increased intelligibility toward the end of the reading passage. For control speakers and speakers with PD, patterns of intelligibility variation across passage reading did not differ with speaking style. For the MS group, intelligibility variation across the passage was dependent on speaking style.

CONCLUSIONS

The presence of intelligibility variation within a reading passage warrants careful selection of speech materials in research and clinical practice. Results further indicate that the crowdsourced VAS rating paradigm is useful to document intelligibility in a reading passage for different cued speaking styles commonly used in treatment for dysarthria.

Quantitative acoustic metrics of vowel production in mandarin-speakers with post-stroke spastic dysarthria

Impairment of vowel production in dysarthria has been highly valued. This study aimed to explore the vowel production of Mandarin-speakers with post-stroke spastic dysarthria in connected speech and to explore the influence of gender and tone on the vowel production. Multiple vowel acoustic metrics, including F1 range, F2 range, vowel space area (VSA), vowel articulation index (VAI) and formant centralization ratio (FCR), were analyzed from vowel tokens embedded in connected speech produced. The participants included 25 clients with spastic dysarthria secondary to stroke (15 males, 10 females) and 25 speakers with no history of neurological disease (15 males, 10 females). Variance analyses were conducted and the results showed that the main effects of population, gender, and tone on F2 range, VSA, VAI, and FCR were all significant. Vowel production became centralized in the clients with post-stroke spastic dysarthria. Vowel production was found to be more centralized in males compared to females. Vowels in neutral tone (T0) were the most centralized among the other tones. The quantitative acoustic metrics of F2 range, VSA, VAI, and FCR were effective in predicting vowel production in Mandarin-speaking clients with post-stroke spastic dysarthria, and hence may be used as powerful tools to assess the speech performance for this population.

Design and Evaluation of Korean Electropalatography (K-EPG)

Recently, the development of medical rehabilitation technology has resulted in an increased interest in speech therapy equipment. In particular, research on articulation therapy for communication disorders is being actively conducted. The existing methods for the diagnosis and treatment of speech disorders, such as traditional tactile perception tests and methods based on the empirical judgment of speech therapists, have many limitations. Moreover, the position and contact force of the tongue are key factors in speech disorders with regards to articulation. This is a very important factor in the distinction of Korean characters such as lax, tense and aspirated consonants. In this study, we proposed a Korean-electropalatography (EPG) system to easily measure and monitor the position and contact force of the tongue during articulation treatment and diagnosis. In our proposed K-EPG system, a sensor was fabricated using an AgCl electrode and biocompatible silicon. Furthermore, the measured signal was analyzed by implementing a bio-signal processing module and monitoring program. In particular, the bio-signal was measured by inserting the device into the palate of an experimental healthy test group (four subjects). Through these experiments, we confirmed that our K-EPG system could be applied to clinical treatment in speech therapy.

Spoken Vocabulary Outcomes of Toddlers With Developmental Delay After Parent-Implemented Augmented Language Intervention

Purpose Early intervention using augmentative and alternative communication (AAC) supports both receptive and expressive language skills. However, many parents and clinicians still worry that augmented language intervention might delay or impair speech development. This study aimed to (a) characterize and analyze the speech sound development of toddlers with developmental delay who participated in a parent-implemented language intervention; (b) examine the accuracy of speech sounds among toddlers who participated in an augmented language intervention using speech-generating devices and toddlers who participated in a traditional, spoken language intervention; and (c) examine the relationship between baseline factors (i.e., receptive and expressive language skills, vocal imitation, and number of unintelligible utterances) and the number of spoken target vocabulary words after intervention. Method This study used extant data from two randomized control trials of parent-implemented language interventions using AAC or spoken language. Out of 109 children who completed the intervention, 45 children produced spoken target vocabulary words at the end of the intervention. We identified and phonetically transcribed spoken target vocabulary words for each child and then classified them based on Shriberg and Kwiatkowski's (1982) developmental sound classes. Results Children's speech sound accuracy was not significantly different across intervention groups. Overall, children who produced more words had more speech sound errors and higher baseline language scores. Intervention group and baseline receptive and expressive language skills significantly predicted the number of spoken target vocabulary words produced at the end of intervention. Conclusions Participation in AAC intervention resulted in significantly more spoken target vocabulary words and no statistically significant differences in speech sound errors when compared to children who received spoken language intervention without AAC. Results support using AAC interventions for very young children without the fear that it will delay speech or spoken language development. Supplemental Material https://doi.org/10.23641/asha.14265365.

Acoustic vowel analysis and speech intelligibility in young adult Hebrew speakers: Developmental dysarthria versus typical development

BACKGROUND

Developmental dysarthria is a motor speech impairment commonly characterized by varying levels of reduced speech intelligibility. The relationship between intelligibility deficits and acoustic vowel space among these individuals has long been noted in the literature, with evidence of vowel centralization (e.g., in English and Mandarin). However, the degree to which this centralization occurs and the intelligibility-acoustic relationship is maintained in different vowel systems has yet to be studied thoroughly. In comparison with American English, the Hebrew vowel system is significantly smaller, with a potentially smaller vowel space area, a factor that may impact upon the comparisons of the acoustic vowel space and its correlation with speech intelligibility. Data on vowel space and speech intelligibility are particularly limited for Hebrew speakers with motor speech disorders.

AIMS

To determine the nature and degree of vowel space centralization in Hebrew-speaking adolescents and young adults with dysarthria, in comparison with typically developing (TD) peers, and to correlate these findings with speech intelligibility scores.

METHODS & PROCEDURES

Adolescents and young adults with developmental dysarthria (secondary to cerebral palsy (CP) and other motor deficits, n = 17) and their TD peers (n = 17) were recorded producing Hebrew corner vowels within single words. For intelligibility assessments, naïve listeners transcribed those words produced by speakers with CP, and intelligibility scores were calculated.

OUTCOMES & RESULTS

Acoustic analysis of vowel formants (F1, F2) revealed a centralization of vowel space among speakers with CP for all acoustic metrics of vowel formants, and mainly for the formant centralization ratio (FCR), in comparison with TD peers. Intelligibility scores were correlated strongly with the FCR metric for speakers with CP.

CONCLUSIONS & IMPLICATIONS

The main results, vowel space centralization for speakers with CP in comparison with TD peers, echo previous cross-linguistic results. The correlation of acoustic results with speech intelligibility carries clinical implications. Taken together, the results contribute to better characterization of the speech production deficit in Hebrew speakers with motor speech disorders. Furthermore, they may guide clinical decision-making and intervention planning to improve speech intelligibility. What this paper adds What is already known on the subject Speech production and intelligibility deficits among individuals with developmental dysarthria (e.g., secondary to CP) are well documented. These deficits have also been correlated with centralization of the acoustic vowel space, although primarily in English speakers. Little is known about the acoustic characteristics of vowels in Hebrew speakers with motor speech disorders, and whether correlations with speech intelligibility are maintained. What this paper adds to existing knowledge This study is the first to describe the acoustic characteristics of vowel space in Hebrew-speaking adolescents and young adults with developmental dysarthria. The results demonstrate a centralization of the acoustic vowel space in comparison with TD peers for all measures, as found in other languages. Correlation between acoustic measures and speech intelligibility scores were also documented. We discuss these results within the context of cross-linguistic comparisons. What are the potential or actual clinical implications of this work? The results confirm the use of objective acoustic measures in the assessment of individuals with motor speech disorders, providing such data for Hebrew-speaking adolescents and young adults. These measures can be used to determine the nature and severity of the speech deficit across languages, may guide intervention planning, as well as measure the effectiveness of intelligibility-based treatment programmes.

Effect of prosodic manipulation on articulatory kinematics and second formant trajectories in children

This study investigated effects of rate reduction and emphatic stress cues on second formant (F2) trajectories and articulatory movements during diphthong production in 11 typically developing school-aged children. F2 extent increased in slow and emphatic stress conditions, and tongue and jaw displacement increased in the emphatic stress condition compared to habitual speech. Tongue displacement significantly predicted F2 extent across speaking conditions. Results suggest that slow rate and emphatic stress cues induce articulatory and acoustic changes in children that may enhance clarity of the acoustic signal. Potential clinical implications for improving speech in children with dysarthria are discussed.

Configuração acústico-articulatória das vogais de mulheres com nódulos vocais e vocalmente saudáveis

RESUMO Objetivo Analisar a configuração acústico-articulatória das vogais em mulheres com nódulos vocais e vocalmente saudáveis. Método Participaram do estudo 12 mulheres com nódulos vocais (GE) e 12 vocalmente saudáveis (GC). Todas as mulheres gravaram frases-veículo com as vogais /a/, /i/ e /u/ em posição tônica, sucedidas e precedidas da oclusiva /p/: “Digo papa baixinho”, “Digo pipa baixinho” e “Digo pupa baixinho”. Posteriormente, foram extraídos os três primeiros formantes (F1, F2 e F3) dessas vogais. Resultados Observou-se diferença nas medidas de F1 para as vogais /a/ e /u/ e F2 para a vogal /a/ entre os dois grupos estudados. Mulheres com nódulos vocais apresentam menor valor dessas medidas em relação às mulheres vocalmente saudáveis. Pacientes com nódulos vocais apresentaram menor intervalo nos valores de F1 e F2 entre as vogais /a/, /i/ e /u/ em relação às mulheres vocalmente saudáveis. Conclusão Mulheres com nódulos vocais apresentam menores valores de F1 e F2, e menor amplitude de movimentação dos articuladores na produção vocálica em relação às mulheres vocalmente saudáveis.

Data-Driven Classification of Dysarthria Profiles in Children With Cerebral Palsy

Purpose

The objectives of this study were to examine different speech profiles among children with dysarthria secondary to cerebral palsy (CP) and to characterize the effect of different speech profiles on intelligibility.

Method

Twenty 5-year-old children with dysarthria secondary to CP and 20 typically developing children were included in this study. Six acoustic and perceptual speech measures were selected to quantify a range of segmental and suprasegmental speech characteristics and were measured from children's sentence productions. Hierarchical cluster analysis was used to identify naturally occurring subgroups of children who had similar profiles of speech features.

Results

Results revealed 4 naturally occurring speech clusters among children: 1 cluster of children with typical development and 3 clusters of children with dysarthria secondary to CP. Two of the 3 dysarthria clusters had statistically equivalent intelligibility levels but significantly differed in articulation rate and degree of hypernasality.

Conclusion

This study provides initial evidence that different speech profiles exist among 5-year-old children with dysarthria secondary to CP, even among children with similar intelligibility levels, suggesting the potential for developing a pediatric dysarthria classification system that could be used to stratify children with dysarthria into meaningful subgroups for studying speech motor development and efficacy of interventions.

Acoustic properties of vowel production in Mandarin-speaking patients with post-stroke dysarthria

This study investigated the acoustic features of vowel production in Mandarin-speaking patients with post-stroke dysarthria (PSD). The subjects included 31 native Mandarin-speaking patients with PSD (age: 25–83 years old) and 38 neurologically normal adults in a similar age range (age: 21–76 years old). Each subject was recorded producing a list of Mandarin monosyllables that included six monophthong vowels (i.e., /a, i, u, ɤ, y, o/) embedded in the /CV/ context. The patients’ speech samples were evaluated by two native Mandarin speakers. The evaluation scores were then used to classify all patients into two levels of severity: mild or moderate-to-severe. Formants (F1 and F2) were extracted from each vowel token. Results showed that all vowel categories in the patients with PSD were produced with more variability than in the healthy speakers. Great overlaps between vowel categories and reduced vowel space were observed in the patients. The magnitude of the vowel dispersion and overlap between vowel categories increased as a function of the severity of the disorder. The deviations of the vowel acoustic features in the patients in comparison to the healthy speakers may provide guidance for clinical rehabilitation to improve the speech intelligibility of patients with PSD.