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Purpose This study investigated perceived speech naturalness estimated by adult listeners in typically developing children and children with dysarthria. We aimed to identify predictors of naturalness among auditory-perceptual parameters and to evaluate the concept of naturalness as a clinical marker of childhood dysarthria. Method In a listening experiment, naive adult listeners rated speech naturalness of 144 typically developing children (3–9 years old) and 28 children with neurological conditions (5–9 years old) on a visual analog scale. Speech samples were recorded using the materials of the Bogenhausen Dysarthria Scales–Childhood Dysarthria, which also provides for auditory-perceptual judgments covering all speech subsystems. Results Children with dysarthria obtained significantly lower naturalness ratings compared to typically developing children. However, there was a substantial age effect observable in the typically developing children; that is, younger typically developing children were also perceived as somewhat unnatural. The ratings of the typically developing children were influenced by the occurrence of developmental speech features; for the children with neurological conditions, specific symptoms of dysarthria had an additional effect. In both groups, the perception of naturalness was predominantly determined by the children's articulation and intelligibility. Conclusions Both symptoms of childhood dysarthria and developmental speech features (e.g., regarding articulation and intelligibility) were associated to some extent with unnatural speech by the listeners. Thus, perceived speech naturalness appears less suitable as a marker of dysarthria in children than in adults.
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Research Article
Speech Naturalness in the Assessment of
Childhood Dysarthria
Theresa Schölderle,
a
Elisabet Haas,
a
and Wolfram Ziegler
a
a
Institute for Phonetics and Speech Processing, Ludwig-Maximilians-Universität München, München, Germany
AR T I CLE I N F O
Article History:
Received January 23, 2023
Revision received March 23, 2023
Accepted April 7, 2023
Editor-in-Chief: Katherine C. Hustad
Editor: Ignatius Nip
https://doi.org/10.1044/2023_AJSLP-23-00023
Correspondence to Theresa Schölderle: theresa.schoelderle@ekn-
muenchen.de. Disclosure: The authors have declared that no competing
financial or nonfinancial interests existed at the time of publication.
AB ST R A C T
Purpose: This study investigated perceived speech naturalness estimated by
adult listeners in typically developing children and children with dysarthria. We
aimed to identify predictors of naturalness among auditory-perceptual parame-
ters and to evaluate the concept of naturalness as a clinical marker of childhood
dysarthria.
Method: In a listening experiment, naive adult listeners rated speech natural-
ness of 144 typically developing children (39 years old) and 28 children with
neurological conditions (59 years old) on a visual analog scale. Speech sam-
ples were recorded using the materials of the Bogenhausen Dysarthria Scales
Childhood Dysarthria, which also provides for auditory-perceptual judgments
covering all speech subsystems.
Results: Children with dysarthria obtained significantly lower naturalness ratings
compared to typically developing children. However, there was a substantial
age effect observable in the typically developing children; that is, younger typi-
cally developing children were also perceived as somewhat unnatural. The rat-
ings of the typically developing children were influenced by the occurrence of
developmental speech features; for the children with neurological conditions,
specific symptoms of dysarthria had an additional effect. In both groups, the
perception of naturalness was predominantly determined by the childrens artic-
ulation and intelligibility.
Conclusions: Both symptoms of childhood dysarthria and developmental
speech features (e.g., regarding articulation and intelligibility) were associated to
some extent with unnatural speech by the listeners. Thus, perceived speech
naturalness appears less suitable as a marker of dysarthria in children than in
adults.
Dysarthria is a speech disorder that can be caused
by various neurological conditions and may affect adults
(e.g., with stroke or Parkinsons disease) as well as chil-
dren (e.g., with cerebral palsy [CP] or genetic syndromes).
By definition, dysarthria is characterized by impairments
of the speech motor subsystems, that is, respiration, pho-
nation, articulation, and prosody (Duffy, 2020). Clinical
assessment is predominantly focused on the speech charac-
teristics directly associated with these motor impairments
(e.g., impaired voice quality, articulatory dysfunction), but
for a comprehensive and ecologically valid description of
the speech disorder, the manifold and highly individual
consequences of the disorder for everyday communication
must also be considered (International Classification of
Functioning, Disability and Health; World Health Organi-
zation, 2001).
So far, research on communication-related parame-
ters both in adults and children with dysarthria has pre-
dominantly focused on speech intelligibility. In adults, sev-
eral studies also addressed perceived speech naturalness,
showing that this concept may add relevant detail to the
picture of communication abilities in dysarthria (Dagenais
& Wilson, 2002; Dagenais et al., 2006; Klopfenstein et al.,
2020; Schölderle et al., 2016; Southwood & Weismer,
1993; Yorkston et al., 1990). Speech naturalness refers to
a rather broad perceptual impression representing the
American Journal of Speech-Language Pathology Vol. 32 16331643 July 2023 Copyright © 2023 American Speech-Language-Hearing Association 1633
... This study was approved by the Medical Faculty's Ethics Committee of the Ludwig-Maximilians-Universität München (LMU Munich). As there is some overlap with previous publications, details on participants, assessment materials, and auditory-perceptual analyses beyond the information provided herein can be obtained from Schölderle et al. (2020Schölderle et al. ( , 2021Schölderle et al. ( , 2022Schölderle et al. ( , 2023 as well as Haas et al. (2021Haas et al. ( , 2022. The present article refers to age and gender estimates in CTD and in CWD collected in a comprehensive listening experiment with adult listeners. ...
... Data on the intelligibility of CTD and of children with neurological conditions were reported in Schölderle et al. (2021) and Haas et al. (2022), respectively. For naturalness ratings in CTD and children with neurological conditions, see Schölderle et al. (2023). ...
Article
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Purpose The purposes of this study were (a) to investigate adult listeners' perceptions of age and gender in typically developing children and children with dysarthria and (b) to identify predictors of their estimates among auditory-perceptual parameters and an acoustic measure of vocal pitch (F0). We aimed to evaluate the influence of dysarthria on the listeners' impressions of age and gender against the background of typical developmental processes. Method In a listening experiment, adult listeners completed age and gender estimates of 144 typically developing children (3–9 years of age) and 25 children with dysarthria (5–9 years of age). The Bogenhausen Dysarthria Scales for Childhood Dysarthria (BoDyS-KiD) were applied to record speech samples and to complete auditory-perceptual judgments covering all speech subsystems. Furthermore, each child's mean F0 was determined from samples of four BoDyS-KiD sentences. Results Age estimates for the typically developing children showed a regression to the mean, whereas children with dysarthria were systematically underestimated in their age. The estimates of all children were predicted by developmental speech features; for the children with dysarthria, specific dysarthria symptoms had an additional effect. We found a significantly higher accuracy of gender attribution in the typically developing children than in the children with dysarthria. The prediction accuracy of the listeners' gender attribution in the preadolescent children by the included speech characteristics was limited. Conclusions Children with dysarthria are more difficult to estimate for their age and gender than their typically developing peers. Dysarthria thus alters the auditory-perceptual impression of indexical speech features in children, which must be considered another facet of the communication disorder associated with childhood dysarthria.
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Purpose This study aimed to describe communication-related parameters (i.e., intelligibility, speech rate, and communication efficiency) and their developmental courses in children with neurological conditions against the background of typical development. In addition, interrelations between the developmental courses of communication-related parameters and auditory-perceptual ratings related to speech subsystems were investigated. Method Fourteen children with neurological conditions (CNC) and 14 typically developing children (CTD), matched for age and gender (four girls; 5;1–8;4 [years;months] at first examination), were assessed at three points in time over an 18-month period. Speech samples were collected using the Bogenhausener Dysarthrie Skalen–Kindliche Dysarthrien (English: Bogenhausen Dysarthria Scales–Childhood Dysarthria), a German tool for the assessment of childhood dysarthria. To assess intelligibility, naïve listeners transcribed audio samples of sentence repetitions of the children. Speech rate was measured by acoustic analyses, and communication efficiency was determined by multiplying the proportion of correctly transcribed syllables with speech rate. Age normalization was performed following a recently published approach. Results On the group level, CNC had conspicuous raw and normalized scores for the three communication-related parameters and were more variable than the CTD group regarding their developmental courses. These differences were more pronounced for intelligibility than for speech rate. A strong relationship between communication-related and speech subsystems–related auditory-perceptual characteristics was apparent only between intelligibility and articulation/resonance. Conclusions For the first time, age-normalized scores for communication-related parameters were reported in children with neurological disorders and put into a developmental context within the framework of a longitudinal study. Age-normalized intelligibility was more vulnerable to large developmental changes than speech rate and was best predicted by changes in articulation and resonance. Overall, this study may contribute to a more comprehensive and valid clinical assessment of childhood dysarthria and to a better understanding of its developmental dynamics.
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Purpose The purpose of this study was to describe childhood dysarthria by means of auditory-perceptual analyses covering all speech subsystems. We aimed to identify the most seriously affected auditory-perceptual dimensions in the observed dysarthria profiles and to detect specific markers of childhood dysarthria against the backdrop of typical speech development. Moreover, the relationship between the speech disorder and other relevant aspects of multiple disability was investigated. Method Thirty-one children with neurologic conditions were assessed with Bogenhausen Dysarthria Scales for Childhood Dysarthria, a German tool for the auditory-perceptual analysis of dysarthria in children. Nine relevant speech dimensions (scales, e.g., voice quality [VOQ]) and 29 individual symptoms (features, e.g., breathy) were evaluated. Moreover, we documented motor, communicative, and cognitive–linguistic measures (i.e., Gross Motor Function Classification System [GMFCS], Communication Function Classification System [CFCS], Test for Reception of Grammar [TROG-D], and memory span). Recently published data from typically developing children were used for the purpose of age normalization. Results Dysarthria severity was moderately correlated with GMFCS and CFCS but not with TROG-D and memory span. At the group level, respiration, articulation, and prosodic modulation were most severely affected, whereas voice function was only mildly affected or even spared in the majority of children. Four features were identified as most relevant markers of childhood dysarthria: conspicuous rhythm/stress pattern, hypernasality, strained–strangled voice, and reduced articulatory precision. Conclusions Childhood dysarthria is part of a complex multiple disability, but speech motor skills may still dissociate from gross-motor and cognitive–linguistic functions. Auditory-perceptual analyses incorporating age norms allow for a comprehensive description and identification of childhood dysarthria.
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Measuring the impact of dysarthria on a patient’s ability to communicate is an integral part of patient management. However, due to the high demands on reliable quantification of communication limitations, hardly any formal clinical tests with approved psychometric properties have been developed so far. This study investigates a web-based assessment of communication impairment in dysarthria, implemented as a web application named KommPaS. The test comprises measures of intelligibility, naturalness, perceived listener effort and communicative efficiency, as well as a total score integrating these parameters. The approach is characterized by a quasi-random access to a large inventory of test materials and to a large group of laypersons as listeners, recruited via online crowdsourcing. To establish the clinical applicability of this new approach, the present paper focuses on two psychometric issues, namely known-groups validity (study 1) and retest-reliability (study 2). Study 1: KommPaS was administered to 54 healthy adults and 100 adult persons with dysarthria. Non-parametric criterion-based norms and sensitivity values were identified for each of the four single variables. Overall classification accuracy of the total score was determined using a ROC analysis. The resulting cutscores showed a high accuracy in the separation of dysarthric patients from healthy speakers for the naturalness and the communication total scores, and moderate sensitivity for the other three parameters. Study 2: A sub-group of 20 patients enrolled in study 1 were administered a second KommPaS examination. ICC analyses revealed good to excellent retest reliabilities for all parameters.
Preprint
Assessing the impact of dysarthria on a patient's ability to communicate should be an integral part of patient management. However, due to the high demands on reliable quantification of communication limitations, hardly any formal clinical tests with approved psycho-metric properties have been developed so far. This study investigates a web-based assessment of communication impairment in dysarthria, named KommPaS. The test comprises measures of intelligibility, naturalness , perceived listener effort and communication efficiency, as well as a total score that integrates these parameters. The approach is characterized by a quasi-random access to a large inventory of test materials and to a large group of naïve listeners, recruited via crowd-sourcing. As part of a larger research program to establish the clinical applicability of this new approach, the present paper focuses on two psychometric issues, namely specificity and sensitivity (study 1) and retest-reliability (study 2). Study 1: KommPaS was administered to 54 healthy adults and 100 adult persons with dysarthria (PWD). Non-parametric criterion-based norms (specificity: 0.95) were used to derive a standard metric for each of the four component variables, and corresponding sensitivity values for the presence of dysarthria were identified. Overall classification accuracy of the total score was determined using a ROC analysis. The resulting cutscores showed a high accuracy in the separation of PWD from healthy speakers for the naturalness and the total score. Study 2: A subgroup of 20 PWD enrolled in study 1 were administered a second KommPaS examination. ICC analyses revealed good to excellent retest reliabilities for all parameters. ARTICLE HISTORY