Changes in voice quality after speech-language therapy intervention in older children with cerebral palsy

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.

Articulatory and Vocal Fold Movement Patterns During Loud Speech in Children With Cerebral Palsy

PURPOSE

Speech motor control changes underlying louder speech are poorly understood in children with cerebral palsy (CP). The current study evaluates changes in the oral articulatory and laryngeal subsystems in children with CP and their typically developing (TD) peers during louder speech.

METHOD

Nine children with CP and nine age- and sex-matched TD peers produced sentence repetitions in two conditions: (a) with their habitual rate and loudness and (b) with louder speech. Lip and jaw movements were recorded with optical motion capture. Acoustic recordings were obtained to evaluate vocal fold articulation.

RESULTS

Children with CP had smaller jaw movements, larger lower lip movements, slower jaw speeds, faster lip speeds, reduced interarticulator coordination, reduced low-frequency spectral tilt, and lower cepstral peak prominences (CPP) in comparison to their TD peers. Both groups produced louder speech with larger lip and jaw movements, faster lip and jaw speeds, increased temporal coordination, reduced movement variability, reduced spectral tilt, and increased CPP.

CONCLUSIONS

Children with CP differ from their TD peers in the speech motor control of both the oral articulatory and laryngeal subsystems. Both groups alter oral articulatory and vocal fold movements when cued to speak loudly, which may contribute to the increased intelligibility associated with louder speech.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24970302.

Neuromuscular adaptations of swallowing and speech in unilateral cerebral palsy: shared and distinctive traits

Our aims were to 1) examine the neuromuscular control of swallowing and speech in children with unilateral cerebral palsy (UCP) compared with typically developing children (TDC), 2) determine shared and separate neuromuscular underpinnings of the two functions, and 3) explore the relationship between this control and behavioral outcomes in UCP. Surface electromyography (sEMG) was used to record muscle activity from the submental and superior and inferior orbicularis oris muscles during standardized swallowing and speech tasks. The variables examined were normalized mean amplitude, time to peak amplitude, and bilateral synchrony. Swallowing and speech were evaluated using standard clinical measures. Sixteen children with UCP and 16 TDC participated (7-12 yr). Children with UCP demonstrated higher normalized mean amplitude and longer time to peak amplitude across tasks than TDC (P < 0.01; and P < 0.02) and decreased bilateral synchrony than TDC for swallows (P < 0.01). Both shared and distinctive neuromuscular patterns were observed between swallowing and speech. In UCP, higher upper lip amplitude during swallows was associated with shorter normalized mealtime durations, whereas higher submental bilateral synchrony was related to longer mealtime durations. Children with UCP demonstrate neuromuscular adaptations for swallowing and speech, which should be further evaluated for potential treatment targets. Furthermore, both shared and distinctive neuromuscular underpinnings between the two functions are documented.NEW & NOTEWORTHY Systematically studying the swallowing and speech of children with UCP is new and noteworthy. We found that they demonstrate neuromuscular adaptations for swallowing and speech compared with typically developing peers. We examined swallowing and speech using carefully designed tasks, similar in motor complexity, which allowed us to directly compare patterns. We found shared and distinctive neuromuscular patterns between swallowing and speech.

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.

Improving speech characteristics of young adults with congenital dysarthria: An exploratory study comparing articulation training and the Beatalk method

INTRODUCTION

This exploratory study compared the effects of two speech therapy approaches on speech characteristics of young adults with congenital dysarthria resulting from various etiologies: a) articulation training focusing on consonant articulation exercises at various levels (isolation, syllables, and words), and b) the Beatalk method, based on human beatboxing, i.e., producing various instrumental sounds in an a-cappella musical context. Both interventions were designed to increase participants' speech intelligibility.

METHODS

Twelve adults with congenital dysarthria and reduced speech intelligibility participated in treatment groups for eight weeks. Six participants were assigned to the articulation training group, and six to the Beatalk group. Intelligibility of single words and continuous speech, voice measures, and oral-diadochokinesis rates were measured before and after the treatment.

RESULTS

The results showed that the Beatalk intervention yielded a significant overall pre- to post-treatment effect. Specifically, it resulted in gains in articulatory accuracy and intelligibility for single words. Improvements were not noted following articulation training.

CONCLUSIONS

The results present initial evidence of the positive effect of the Beatalk method as an intervention tool for adults with congenital dysarthria. This relatively easy-to-learn technique shows promise, as it involves intense and repetitive production of speech sounds while controlling rhythm and breathing in an enjoyable context.

Perceptual and Acoustic Effects of Dual-Focus Speech Treatment in Children With Dysarthria

Purpose Children with dysarthria secondary to cerebral palsy may experience reduced speech intelligibility and diminished communicative participation. However, minimal research has been conducted examining the outcomes of behavioral speech treatments in this population. This study examined the effect of Speech Intelligibility Treatment (SIT), a dual-focus speech treatment targeting increased articulatory excursion and vocal intensity, on intelligibility of narrative speech, speech acoustics, and communicative participation in children with dysarthria. Method American English-speaking children with dysarthria (n = 17) received SIT in a 3-week summer camplike setting at Columbia University. SIT follows motor-learning principles to train the child-friendly, dual-focus strategy, "Speak with your big mouth and strong voice." Children produced a story narrative at baseline, immediate posttreatment (POST), and at 6-week follow-up (FUP). Outcomes were examined via blinded listener ratings of ease of understanding (n = 108 adult listeners), acoustic analyses, and questionnaires focused on communicative participation. Results SIT resulted in significant increases in ease of understanding at POST, that were maintained at FUP. There were no significant changes to vocal intensity, speech rate, or vowel spectral characteristics, with the exception of an increase in second formant difference between vowels following SIT. Significantly enhanced communicative participation was evident at POST and FUP. Considerable variability in response to SIT was observed between children. Conclusions Dual-focus treatment shows promise for improving intelligibility and communicative participation in children with dysarthria, although responses to treatment vary considerably across children. Possible mechanisms underlying the intelligibility gains, enhanced communicative participation, and variability in treatment effects are discussed.

Effects of speech cues in French-speaking children with dysarthria

BACKGROUND

Articulatory excursion and vocal intensity are reduced in many children with dysarthria due to cerebral palsy (CP), contributing to the children's intelligibility deficits and negatively affecting their social participation. However, the effects of speech-treatment strategies for improving intelligibility in this population are understudied, especially for children who speak languages other than English. In a cueing study on English-speaking children with dysarthria, acoustic variables and intelligibility improved when the children were provided with cues aimed to increase articulatory excursion and vocal intensity. While French is among the top 20 most spoken languages in the world, dysarthria and its management in French-speaking children are virtually unexplored areas of research. Information gleaned from such research is critical for providing an evidence base on which to provide treatment.

AIMS

To examine acoustic and perceptual changes in the speech of French-speaking children with dysarthria, who are provided with speech cues targeting greater articulatory excursion (French translation of 'speak with your big mouth') and vocal intensity (French translation of 'speak with your strong voice'). This study investigated whether, in response to the cues, the children would make acoustic changes and listeners would perceive the children's speech as more intelligible.

METHODS & PROCEDURES

Eleven children with dysarthria due to CP (six girls, five boys; ages 4;11-17;0 years; eight with spastic CP, three with dyskinetic CP) repeated pre-recorded speech stimuli across three speaking conditions (habitual, 'big mouth' and 'strong voice'). Stimuli were sentences and contrastive words in phrases. Acoustic analyses were conducted. A total of 66 Belgian-French listeners transcribed the children's utterances orthographically and rated their ease of understanding on a visual analogue scale at sentence and word levels.

OUTCOMES & RESULTS

Acoustic analyses revealed significantly longer duration in response to the big mouth cue at sentence level and in response to both the big mouth and strong voice cues at word level. Significantly higher vocal sound-pressure levels were found following both cues at sentence and word levels. Both cues elicited significantly higher first-formant vowel frequencies and listeners' greater ease-of-understanding ratings at word level. Increases in the percentage of words transcribed correctly and in sentence ease-of-understanding ratings, however, did not reach statistical significance. Considerable variability between children was observed.

CONCLUSIONS & IMPLICATIONS

Speech cues targeting greater articulatory excursion and vocal intensity yield significant acoustic changes in French-speaking children with dysarthria. However, the changes may only aid listeners' ease of understanding at word level. The significant findings and great inter-speaker variability are generally consistent with studies on English-speaking children with dysarthria, although changes appear more constrained in these French-speaking children. What this paper adds What is already known on the subject According to the only study comparing effects of speech-cueing strategies on English-speaking children with dysarthria, intelligibility increases when the children are provided with cues aimed to increase articulatory excursion and vocal intensity. Little is known about speech characteristics in French-speaking children with dysarthria and no published research has explored effects of cueing strategies in this population. What this paper adds to existing knowledge This paper is the first study to examine the effects of speech cues on the acoustics and intelligibility of French-speaking children with CP. It provides evidence that the children can make use of cues to modify their speech, although the changes may only aid listeners' ease of understanding at word level. What are the potential or actual clinical implications of this work? For clinicians, the findings suggest that speech cues emphasizing increasing articulatory excursion and vocal intensity show promise for improving the ease of understanding of words produced by francophone children with dysarthria, although improvements may be modest. The variability in the responses also suggests that this population may benefit from a combination of such cues to produce words that are easier to understand.

Construct Validity of the Viking Speech Scale

OBJECTIVE

The Viking Speech Scale (VSS) reliably classifies the speech performance of children with cerebral palsy. This paper aims to establish the construct validity of the VSS by testing the extent to which percentage intelligibility in single word speech and connected speech predicts VSS rating.

PATIENTS AND METHODS

This is a secondary analysis of two sets of anonymised data collected for previous research. The full data set comprised 79 children with cerebral palsy from the US (n = 43) and the UK (n = 36): (43 boys, 36 girls); mean age 7.2 years (SD 3.3). Single word intelligibility was measured using the TOCS+ words for US children and Children's Speech Intelligibility Measure for the UK children. Connected speech intelligibility was measured from a subset of repeated sentences in TOCS+ for US children and picture description for the UK children. We used ordinal logistic regression to examine prediction of VSS rating by percentage single word and connected speech intelligibility scores in both samples.

RESULTS

Percentage single word intelligibility and connected speech intelligibility predicted VSS rating in univariate and multivariate regression models for both the US and UK samples.

CONCLUSION

Intelligibility predicts VSS for both single words and connected speech, establishing the construct validity of VSS.

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.

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

PURPOSE

This study explored the speech characteristics of Mandarin-speaking children with cerebral palsy (CP) and typically developing (TD) children to determine (a) how children in the 2 groups may differ in their speech patterns and (b) the variables correlated with speech intelligibility for words and sentences.

METHOD

Data from 6 children with CP and a clinical diagnosis of moderate dysarthria were compared with data from 9 TD children using a multiple speech subsystems approach. Acoustic and perceptual variables reflecting 3 speech subsystems (articulatory-phonetic, phonatory, and prosodic), and speech intelligibility, were measured based on speech samples obtained from the Test of Children's Speech Intelligibility in Mandarin (developed in the lab for the purpose of this research).

RESULTS

The CP and TD children differed in several aspects of speech subsystem function. Speech intelligibility scores in children with CP were influenced by all 3 speech subsystems, but articulatory-phonetic variables had the highest correlation with word intelligibility. All 3 subsystems influenced sentence intelligibility.

CONCLUSION

Children with CP demonstrated deficits in speech intelligibility and articulation compared with TD children. Better speech sound articulation influenced higher word intelligibility, but did not benefit sentence intelligibility.

Acoustic changes in the speech of children with cerebral palsy following an intensive program of dysarthria therapy

BACKGROUND

The speech intelligibility of children with dysarthria and cerebral palsy has been observed to increase following therapy focusing on respiration and phonation.

AIMS

To determine if speech intelligibility change following intervention is associated with change in acoustic measures of voice.

METHODS & PROCEDURES

We recorded 16 young people with cerebral palsy and dysarthria (nine girls; mean age 14 years, SD = 2; nine spastic type, two dyskinetic, four mixed; one Worster-Drought) producing speech in two conditions (single words, connected speech) twice before and twice after therapy focusing on respiration, phonation and rate. In both single-word and connected speech we measured vocal intensity (root mean square-RMS), period-to-period variability (Shimmer APQ, Jitter RAP and PPQ) and harmonics-to-noise ratio (HNR). In connected speech we also measured mean fundamental frequency, utterance duration in seconds and speech and articulation rate (syllables/s with and without pauses respectively). All acoustic measures were made using Praat. Intelligibility was calculated in previous research.

OUTCOMES & RESULTS

In single words statistically significant but very small reductions were observed in period-to-period variability following therapy: Shimmer APQ -0.15 (95% CI = -0.21 to -0.09); Jitter RAP -0.08 (95% CI = -0.14 to -0.01); Jitter PPQ -0.08 (95% CI = -0.15 to -0.01). No changes in period-to-period perturbation across phrases in connected speech were detected. However, changes in connected speech were observed in phrase length, rate and intensity. Following therapy, mean utterance duration increased by 1.11 s (95% CI = 0.37-1.86) when measured with pauses and by 1.13 s (95% CI = 0.40-1.85) when measured without pauses. Articulation rate increased by 0.07 syllables/s (95% CI = 0.02-0.13); speech rate increased by 0.06 syllables/s (95% CI = < 0.01-0.12); and intensity increased by 0.03 Pascals (95% CI = 0.02-0.04). There was a gradual reduction in mean fundamental frequency across all time points (-11.85 Hz, 95% CI = -19.84 to -3.86). Only increases in the intensity of single words (0.37 Pascals, 95% CI = 0.10-0.65) and reductions in fundamental frequency (-0.11 Hz, 95% CI = -0.21 to -0.02) in connected speech were associated with gains in intelligibility.

CONCLUSIONS & IMPLICATIONS

Mean reductions in impairment in vocal function following therapy observed were small and most are unlikely to be clinically significant. Changes in vocal control did not explain improved intelligibility.

Intonation patterns in older children with cerebral palsy before and after speech intervention

PURPOSE

This paper examined the production of intonation patterns in children with developmental dysarthria associated with cerebral palsy (CP) prior to and after speech intervention focussing on respiration and phonation. The study further sought to establish whether intonation performance might be related to changes in speech intelligibility.

METHOD

Intonation patterns were examined using connected speech samples of 15 older children with moderate to severe developmental dysarthria due to CP (9 females; age range: 11-18). Recordings were made prior to and after speech intervention based on a systems approach. Analyses are focussed on the use of intonation patterns, pitch accentuation and phrasing.

RESULT

Group analyses showed a significant increase in the use of rising intonation patterns after intervention. There were also some indications that this increase might have been related to gains in speech intelligibility for some of the children. No changes were observed regarding pitch accentuation and phrasing following intervention.

CONCLUSION

The findings highlight that changes can occur in the use of intonation patterns in children with dysarthria and CP following speech systems intervention. It is hypothesised that the emergence of the rising pattern in some of the children's intonational inventories possibly reflected improved breath support and control of laryngeal muscles.

Speech therapy for children with dysarthria acquired before three years of age

BACKGROUND

Children with motor impairments often have the motor speech disorder dysarthria, a condition which effects the tone, strength and co-ordination of any or all of the muscles used for speech. Resulting speech difficulties can range from mild, with slightly slurred articulation and breathy voice, to profound, with an inability to produce any recognisable words. Children with dysarthria are often prescribed communication aids to supplement their natural forms of communication. However, there is variation in practice regarding the provision of therapy focusing on voice and speech production. Descriptive studies have suggested that therapy may improve speech, but its effectiveness has not been evaluated.

OBJECTIVES

To assess whether any speech and language therapy intervention aimed at improving the speech of children with dysarthria is more effective in increasing children's speech intelligibility or communicative participation than no intervention at all , and to compare the efficacy of individual types of speech language therapy in improving the speech intelligibility or communicative participation of children with dysarthria.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2015 , Issue 7 ), MEDLINE, EMBASE, CINAHL , LLBA, ERIC, PsychInfo, Web of Science, Scopus, UK National Research Register and Dissertation Abstracts up to July 2015, handsearched relevant journals published between 1980 and July 2015, and searched proceedings of relevant conferences between 1996 to 2015. We placed no restrictions on the language or setting of the studies. A previous version of this review considered studies published up to April 2009. In this update we searched for studies published from April 2009 to July 2015.

SELECTION CRITERIA

We considered randomised controlled trials and studies using quasi-experimental designs in which children were allocated to groups using non-random methods.

DATA COLLECTION AND ANALYSIS

One author (LP) conducted searches of all databases, journals and conference reports. All searches included a reliability check in which a second review author independently checked a random sample comprising 15% of all identified reports. We planned that two review authors would independently assess the quality and extract data from eligible studies.

MAIN RESULTS

No randomised controlled trials or group studies were identified.

AUTHORS' CONCLUSIONS

This review found no evidence from randomised trials of the effectiveness of speech and language therapy interventions to improve the speech of children with early acquired dysarthria. Rigorous, fully powered randomised controlled trials are needed to investigate if the positive changes in children's speech observed in phase I and phase II studies are generalisable to the population of children with early acquired dysarthria served by speech and language therapy services. Research should examine change in children's speech production and intelligibility. It must also investigate children's participation in social and educational activities, and their quality of life, as well as the cost and acceptability of interventions.