Dysarthria in Mandarin-Speaking Children With Cerebral Palsy: Speech Subsystem Profiles

The Relationship Between Voice Parameters and Speech Intelligibility: A Scoping Review

OBJECTIVE

To synthesize existing evidence of the relationship between voice parameters and speech intelligibility.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for Scoping Review (PRISMA-ScR) guidelines, 13 databases were searched and a manual search was conducted. A narrative synthesis of methodological quality, study characteristics, participant demographics, voice parameter categorization, and their relationship to speech intelligibility was conducted. A Grading of Recommendations Assessment, Development, and Evaluation (GRADE) assessment was also performed.

RESULTS

A total of 5593 studies were retrieved, and 30 eligible studies were included in the final scoping review. The studies were given scores of 10-25 (average 16.93) out of 34 in the methodological quality assessment. Research that analyzed voice parameters related to speech intelligibility, encompassing perceptual, acoustic, and aerodynamic parameters, was included. Validated and nonvalidated perceptual voice assessments showed divergent results regarding the relationship between perceptual parameters and speech intelligibility. The relationship between acoustic parameters and speech intelligibility was found to be complex and the results were inconsistent. The limited research on aerodynamic parameters did not reach a consensus on their relationship with speech intelligibility. Studies in which listeners were not speech-language pathologists (SLPs) far outnumbered those with SLP listeners, and research conducted in English contexts significantly exceeded that in non-English contexts. The GRADE evaluation indicated that the quality of evidence varied from low to moderate.

DISCUSSION

The results for the relationship between voice parameters and intelligibility showed significant heterogeneity. Future research should consider age-related voice changes and include diverse age groups. To enhance validity and comparability, it will be necessary to report effect sizes, tool validity, inter-rater reliability, and calibration procedures. Voice assessments should account for the validation status of tools because of their potential impact on the outcomes. The linguistic context may also influence the results.

Revisiting Dysarthria Treatment Across Languages: The Hybrid Approach

PURPOSE

Ten years after Miller and Lowit's (2014) groundbreaking book providing a cross-linguistic perspective on motor speech disorders, we ask where we are regarding dysarthria treatment across languages in two specific populations: adults with Parkinson's disease (PD) and children with cerebral palsy (CP).

METHOD

In this commentary, we consider preliminary evidence for both language-independent and language-specific approaches to treatment and propose a hybrid approach to speech treatment across languages, centered on the individual with dysarthria who speaks any given language.

CONCLUSIONS

Treatment research on individuals with dysarthria secondary to PD and CP is advancing, but several areas remain to be explored. Next steps are suggested for addressing the paucity and complexity of cross-linguistic speech treatment research.

Marginal and Canonical Babbling in 10 Infants at Risk for Cerebral Palsy

PURPOSE

This study is a preliminary quantification and characterization of the development of marginal and canonical syllable patterns in 10 infants at risk for cerebral palsy (CP).

METHOD

We calculated marginal and canonical babbling ratios from parent-infant laboratory recordings of 10 infants at two time points, approximately 13 and 16 months of age. The frequency and diversity of labial, coronal, and velar types of marginal and canonical syllables were also examined. Differences across three outcome groups were compared: infants later diagnosed with CP (n = 3, CP group), risk of CP due to ongoing gross motor delays (n = 4, risk group), and current typically developing status with resolved gross motor delays (n = 3, TDx group). Performance on the Mullen Scales was included for perspective on cognitive development.

RESULTS

Higher marginal syllable ratios were observed in the CP and risk groups than the TDx group. An increasing canonical syllable ratio across the two ages was consistently observed in the TDx group. The TDx group produced a greater frequency and diversity of canonical syllable types than the risk and CP groups, and of marginal syllable types than the CP group.

CONCLUSIONS

This study offers preliminary support for the possibility that speech motor impairment in infants with CP have the potential to be observed and quantified early in vocal development prior to the expected onset of first words. Prolonged rates of marginal syllable forms may be suggestive of speech motor impairment; however, additional longitudinal outcome data over a longer time course and a larger sample of infants are needed to provide further support for this possibility.

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.

Oral and Laryngeal Diadochokinesis Across the Life Span: A Scoping Review of Methods, Reference Data, and Clinical Applications

PURPOSE

The aim of this study was to conduct a scoping review of research on oral and laryngeal diadochokinesis (DDK) in children and adults, either typically developing/developed or with a clinical diagnosis.

METHOD

Searches were conducted with PubMed/MEDLINE, Google Scholar, CINAHL, and legacy sources in retrieved articles. Search terms included the following: DDK, alternating motion rate, maximum repetition rate, sequential motion rate, and syllable repetition rate.

RESULTS

Three hundred sixty articles were retrieved and included in the review. Data source tables for children and adults list the number and ages of study participants, DDK task, and language(s) spoken. Cross-sectional data for typically developing children and typically developed adults are compiled for the monosyllables /pʌ/, /tʌ/, and /kʌ/; the trisyllable /pʌtʌkʌ/; and laryngeal DDK. In addition, DDK results are summarized for 26 disorders or conditions.

DISCUSSION

A growing number of multidisciplinary reports on DDK affirm its role in clinical practice and research across the world. Atypical DDK is not a well-defined singular entity but rather a label for a collection of disturbances associated with diverse etiologies, including motoric, structural, sensory, and cognitive. The clinical value of DDK can be optimized by consideration of task parameters, analysis method, and population of interest.

Consonantal Landmarks as Predictors of Dysarthria among English-Speaking Adults with Cerebral Palsy

The current study explored the possibility that the consonantal landmarks served as predictors of dysarthric speech produced by English-speaking adults with cerebral palsy (CP). Additionally, the relationship between the perceptual severity of dysarthric speech and the consonantal landmarks was explored. The analyses included 210 sentences from the TORGO database produced by seven English-speaking CP speakers with dysarthria and seven typically developing controls matched in age and gender. The results indicated that the clinical group produced more total landmark features than did the control group. A binominal regression analysis revealed that the improper control of laryngeal vibration and the inability to tactically control the energy in a voiced segment would lead to the higher likelihood of dysarthric speech. A multinominal regression analysis revealed that producing too many +v and −v landmark features would lead to higher perceptual severity levels among the CP speakers. Together with literature, the current study proposed that the landmark-based acoustic analysis could quantify the differences in consonantal productions between dysarthric and non-dysarthric speech and reflect the underlying speech motor deficits of the population in concern.

Can the Vocal Expression of Intellectually Disabled Individuals Be Used as a Pain Indicator? Initial Findings Supporting a Possible Novice Assessment Method

Pain is difficult to assess in non-verbal populations such as individuals with intellectual and developmental disability (IDD). Due to scarce research in this area, pain assessment for individuals with IDD is still lacking, leading to maltreatment. To improve medical care for individuals with IDD, immediate, reliable, easy to use pain detection methods should be developed. The goal of this preliminary study was to examine the sensitivity of acoustic features of vocal expressions in identifying pain for adults with IDD, assessing their feasibility as a pain detection indicator for those individuals. Such unique pain related vocal characteristics may be used to develop objective pain detection means. Adults with severe-profound IDD level (N = 9) were recorded in daily activities associated with pain (during diaper changes), or without pain (at rest). Spontaneous vocal expressions were acoustically analyzed to assess several voice characteristics. Analyzing the data revealed that pain related vocal expressions were characterized by significantly higher number of pulses and higher shimmer values relative to no-pain vocal expressions. Pain related productions were also characterized by longer duration, higher jitter and Cepstral Peak Prominence values, lower Harmonic-Noise Ratio, lower difference between the amplitude of the 1st and 2nd harmonic (corrected for vocal tract influence; H1H2c), and higher mean and standard deviation of voice fundamental frequency relative to no-pain related vocal productions, yet these findings were not statistically significant, possibly due to the small and heterogeneous sample. These initial results may prompt further research to explore the possibility to use pain related vocal output as an objective and easily identifiable indicator of pain in this population.

Intensive voice treatment (the Lee Silverman Voice Treatment [LSVT®LOUD]) for individuals with Wilson's disease and adult cerebral palsy: two case reports

Objective: In this case report, we aimed to examine the effects of an intensive voice treatment (the Lee Silverman Voice Treatment [LSVT^®LOUD]) for Wilson's disease (WD), and adult cerebral palsy (CP), and dysarthria.Method: The participants received LSVT^®LOUD four times a week for 4 weeks. Acoustic, perceptual (GRBAS) analyses were performed and data from the Voice Handicap Index (VHI) were obtained before and after treatment.Results: Besides the Harmonics-to Noise Ratio (HNR) value (dB) of the participant with WD, for both participants' fundamental frequencies (Hz), jitter (%), and shimmer (%) values showed significant differences (p < .05) after therapy. Both participants showed significant improvements (p < .05) in the duration (s) and the sound pressure level (dB, SPL) of sustained vowel phonation (/a/), in SPL (dB) of pitch range (high and low /a/) and reading and conversation (p < .01). There was a positive improvement in the high-frequency values (Hz) of both participants but not in the low-frequency values (Hz) in the participant with WD. Perceptual analysis with GRBAS judgements of sustained vowel (/a/) and paragraph reading of two participants also showed improvement. After therapy, perceived loudness of the participants' voice increased.Conclusions: The findings provide some preliminary observations that the individuals with WD and the adult individuals with CP can respond positively to intensive speech treatment such as LSVT^®LOUD. Further studies are needed to investigate speech treatments specific to WD and adult CP.

Developmental Courses in Childhood Dysarthria: Longitudinal Analyses of Auditory-Perceptual Parameters

Purpose The aim of this longitudinal study was to describe developmental courses of childhood dysarthria against the background of typical speech motor development by collecting auditory-perceptual data. Method Fourteen children (four girls, 10 boys; 5;1-8;4 [years;months] at Time 1) with neurological conditions (CNC) and 14 typically developing children (CTD) matched for age and gender were assessed at three points in time over an 18-month period. Speech samples were collected using the Bogenhausener Dysarthrie Skalen-Kindliche Dysarthrien (BoDyS-KiD; in English: Bogenhausen Dysarthria Scales-Childhood Dysarthria), a German tool for the assessment of childhood dysarthria, and analyzed by means of nine perceptual scales covering all clinically relevant speech components. Age normalization was performed according to a method published recently. Data from the matched controls were used to estimate whether the gradients of the CNC group's developmental trajectories exceeded those of typical development. Results The children with neurological conditions presented heterogeneous speech profiles with a wide range of severity. At the group level, relatively stable trajectories of the age-normalized dysarthria total score were found over the observation period. The nine perceptual scales showed more or less parallel developments. All patients except two followed the growth curve describing the developmental course of the typically developing children. Conclusions Most children took advantage of the developmental dynamics as they developed parallel to the age norm. With its comprehensive description of the developmental courses of 14 children with neurological conditions, this study may contribute to a more valid, statistically verified clinical assessment of the course of childhood dysarthria.

Auditory-Perceptual Features of Speech in Children and Adults With Down Syndrome: A Speech Profile Analysis

Purpose The aim of this study was to determine how the speech disorder profiles in Down syndrome (DS) relate to reduced intelligibility, atypical overall quality, and impairments in the subsystems of speech production (phonation, articulation, resonance, and prosody). Method Auditory-perceptual ratings of intelligibility, overall quality, and features associated with the subsystems of speech production were obtained from recordings of 79 children and adults with DS. Ratings were made for sustained vowels (62 of 79 speakers) and short sentences (79 speakers). The data were analyzed to determine the severity of the affected features in each speaking task and to detect patterns in the group data by means of principal components analysis. Results Reduced intelligibility was noted in 90% of the speakers, and atypical overall speech quality was noted in 100%. Affected speech features were distributed across the speech production subsystems. Principal components analysis revealed four components each for the vowel and sentence tasks, showing that individuals with DS are not homogeneous in the features of their speech disorder. Discussion The speech disorder in DS is complex in its perceptual features and reflects impairments across the subsystems of speech production, but the pattern is not uniform across individuals, indicating that attention must be given to individual variation in designing treatments.

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.

Fricative productions of Mandarin-speaking children with cerebral palsy: the case of five-year-olds

This study aimed at improving the understanding of speech characteristics of fricatives produced by five-year-old Mandarin-acquiring children with cerebral palsy (CP). Productions from nine CP children and nine gender-and-age-matched typically developing (TD) children were collected and analyzed. Results from transcription indicated that the CP group had lower production accuracy rates for all the five fricatives in Mandarin Chinese. Additionally, when the CP children failed to articulate the target fricative segments, they tended to delete them or convert them into non-continuant segments. Results from acoustic analyses indicated that the M2 values of the labiodental [f] and the M1 and M2 values of the alveolar [s] were higher among the CP children. The experimental results revealed that: (1) Observable differences were available once the age of the groups was properly controlled and acoustical measurements were adopted; (2) the lack of finer-grained speech motor control abilities among CP children were reflected in the M1 and M2 values; (3) for segments at the anterior places, the clinical group failed to extend the articulatory gestures to the desirable positions. It is suggested that future studies focusing on different age groups and children with different native languages would help to approach the nature of articulatory barriers among individuals with CP.

Longitudinal Growth in Single Word Intelligibility Among Children With Cerebral Palsy From 24 to 96 Months of Age: Predicting Later Outcomes From Early Speech Production

Purpose Children with cerebral palsy (CP) are at risk for significant communication problems. Reduced speech intelligibility is common, even for those who do not have speech motor deficits. Development of intelligibility has not been comprehensively quantified in children with CP; as a result, we are currently unable to predict later speech outcomes. Such information would advance treatment decision making. We sought to examine growth in speech intelligibility among children with CP using a prospective longitudinal design, with a focus on age of crossing target intelligibility thresholds, age of greatest intelligibility growth, and how well intelligibility at 36 months predicted intelligibility at 96 months. Method Sixty-nine children with CP were followed longitudinally between 24 and 96 months of age. A total of 566 time points were examined across children ( M = 8.2 time points per child, SD = 2.6). We fitted a nonlinear random effects model for longitudinal observations and then used the fitted model trajectories to generate descriptive analyses of growth. We used results of the model to generate a set of simulations, which we analyzed to determine how well 36-month intelligibility data predicted 96-month data. Results Half of children crossed 25% and 50% intelligibility thresholds at 36 and 49 months of age, respectively. Slightly more than half of children did not reach 75% intelligibility by 96 months of age. Age of crossing 25%, 50%, and 75% intelligibility thresholds was highly negatively correlated with intelligibly at 96 months. Children had the steepest intelligibility growth at 36 months, followed by 48 and 60 months. Intelligibility at 36 months was highly predictive of intelligibility at 96 months. Conclusions The developmental window from 3 to 5 years constitutes a time of rapid growth in speech intelligibility in children with CP. Children who cross intelligibility thresholds of 25%, 50%, and 75% at earlier ages have better outcomes when they are older; early performance is highly predictive of later speech intelligibility outcomes. Children with CP as a group have delayed speech intelligibility development but are still growing through 96 months of age.