Wolfram Ziegler

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 ( F 0). 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 F 0 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.

In recent decades, we have witnessed a wealth of theoretical work and proof-of-principle studies on dysarthria, including descriptions and classifications of dysarthric speech patterns, new and refined assessment methods, and innovative experimental intervention trials

Purpose: In current clinical practice, intelligibility of dysarthric speech is commonly assessed by speech-language therapists (SLTs), in most cases by the therapist caring for the patient being diagnosed. Since SLTs are familiar with dysarthria in general and with the speech of the individual patient to be assessed in particular, they have an adaptation advantage in understanding the patient's utterances. We examined whether and how listeners' assessments of communication-related speech parameters vary as a function of their familiarity with dysarthria in general and with the diagnosed patients in particular. Method: Intelligibility, speech naturalness, and perceived listener effort were assessed in 20 persons with dysarthria (PWD). Patients' speech samples were judged by the individual treating therapists, five dysarthria experts who were unfamiliar with the patients, and crowdsourced naïve listeners. Adaptation effects were analyzed using (a) linear mixed models of overall scoring levels, (b) regression models of severity dependence, (c) network analyses of between-listener and between-parameter relationships, and (d) measures of intra- and interobserver consistency. Results: Significant advantages of dysarthria experts over laypeople were found in all parameters. An overall advantage of the treating therapists over nonfamiliar experts was only seen in listening effort. Severity-dependent adaptation effects occurred in all parameters. The therapists' responses were heterogeneous and inconsistent with those of the unfamiliar experts and the naïve listeners. Conclusions: The way SLTs evaluate communication-relevant speech parameters of the PWD whom they care for is influenced not only by adaptation benefits but also by therapeutic biases. This finding weakens the validity of assessments of communication-relevant speech parameters by the treating therapists themselves and encourages the development and use of alternative methods.

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.

Purpose: Previous research on motor speech disorders (MSDs) in primary pro-gressive aphasia (PPA) has largely focused on patients with the nonfluent/ agrammatic variant of PPA (nfvPPA), with few systematic descriptions of MSDs in variants other than nfvPPA. There has also been an emphasis on studying apraxia of speech, whereas less is known about dysarthria or other forms of MSDs. This study aimed to examine the qualitative and quantitative characteristics of MSDs in a prospective sample of individuals with PPA independent of subtype. Method: We included 38 participants with a root diagnosis of PPA according to current consensus criteria, including one case with primary progressive apraxia of speech. Speech tasks comprised various speech modalities and levels of complexity. Expert raters used a novel protocol for auditory speech analyses covering all major dimensions of speech. Results: Of the participants, 47.4% presented with some form of MSD. Individ-ual speech motor profiles varied widely with respect to the different speech dimensions. Besides apraxia of speech, we observed different dysarthria syn-dromes, special forms of MSDs (e.g., neurogenic stuttering), and mixed forms. Degrees of severity ranged from mild to severe. We also observed MSDs in patients whose speech and language profiles were incompatible with nfvPPA. Conclusions: The results confirm that MSDs are common in PPA and can man-ifest in different syndromes. The findings emphasize that future studies of MSDs in PPA should be extended to all clinical variants and should take into account the qualitative characteristics of motor speech dysfunction across speech dimensions. Supplemental Material: https://doi.org/10.23641/asha.22555534

Nonspeech (or paraspeech) parameters are widely used in clinical assessment of speech impairment in persons with dysarthria (PWD). Virtually every standard clinical instrument used in dysarthria diagnostics includes nonspeech parameters, often in considerable numbers. While theoretical considerations have challenged the validity of these measures as markers of speech impairment, only a few studies have directly examined their relationship to speech parameters on a broader scale. This study was designed to investigate how nonspeech parameters commonly used in clinical dysarthria assessment relate to speech characteristics of dysarthria in individuals with movement disorders. Maximum syllable repetition rates, accuracies, and rates of isolated and repetitive nonspeech oral–facial movements and maximum phonation times were compared with auditory–perceptual and acoustic speech parameters. Overall, 23 diagnostic parameters were assessed in a sample of 130 patients with movement disorders of six etiologies. Each variable was standardized for its distribution and for age and sex effects in 130 neurotypical speakers. Exploratory Graph Analysis (EGA) and Confirmatory Factor Analysis (CFA) were used to examine the factor structure underlying the diagnostic parameters. In the first analysis, we tested the hypothesis that nonspeech parameters combine with speech parameters within diagnostic dimensions representing domain–general motor control principles. In a second analysis, we tested the more specific hypotheses that diagnostic parameters split along effector (lip vs. tongue) or functional (speed vs. accuracy) rather than task boundaries. Our findings contradict the view that nonspeech parameters currently used in dysarthria diagnostics are congruent with diagnostic measures of speech characteristics in PWD.

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.

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.

This article addresses the question of whether data from neurological populations can inform basic phonetic research. An approach is reviewed in which speech error data from patients with articulation disorders after a stroke were used to model articulation planning processes.The first section addresses a controversy in cognitive neuroscience about the extent to which data from neurological patients can enrich research in cognitive science at all. It introduces post-stroke apraxia of speech (AOS) as a clinical model of a process termed speech motor planning, suggesting that speech data from patients with AOS can inform phonetic theories about articulatory control.The second section explains how speech error data from patients with AOS were used to develop a measure of articulatory ease that integrates facilitating and complicating factors across different phonological levels, from the articulatory gesture to the phonological word.Section 3 presents previously unpublished data to exemplify how this model can be applied to typical speech, e.g., in studies investigating interactions between lexical and articulatory parameters or in developmental studies of word learning. In a final section, the main line of reasoning is summarized and limitations of this work are discussed.