Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
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- All Subjects: Speech therapy
Description
Often termed the "gold standard" in the differential diagnosis of dysarthria, the etiology-based Mayo Clinic classification approach has been used nearly exclusively by clinicians since the early 1970s. However, the current descriptive method results in a distinct overlap of perceptual features across various etiologies, thus limiting the clinical utility of such a system for differential diagnosis. Acoustic analysis may provide a more objective measure for improvement in overall reliability (Guerra & Lovely, 2003) of classification. The following paper investigates the potential use of a taxonomical approach to dysarthria. The purpose of this study was to identify a set of acoustic correlates of perceptual dimensions used to group similarly sounding speakers with dysarthria, irrespective of disease etiology. The present study utilized a free classification auditory perceptual task in order to identify a set of salient speech characteristics displayed by speakers with varying dysarthria types and perceived by listeners, which was then analyzed using multidimensional scaling (MDS), correlation analysis, and cluster analysis. In addition, discriminant function analysis (DFA) was conducted to establish the feasibility of using the dimensions underlying perceptual similarity in dysarthria to classify speakers into both listener-derived clusters and etiology-based categories. The following hypothesis was identified: Because of the presumed predictive link between the acoustic correlates and listener-derived clusters, the DFA classification results should resemble the perceptual clusters more closely than the etiology-based (Mayo System) classifications. Results of the present investigation's MDS revealed three dimensions, which were significantly correlated with 1) metrics capturing rate and rhythm, 2) intelligibility, and 3) all of the long-term average spectrum metrics in the 8000 Hz band, which has been linked to degree of phonemic distinctiveness (Utianski et al., February 2012). A qualitative examination of listener notes supported the MDS and correlation results, with listeners overwhelmingly making reference to speaking rate/rhythm, intelligibility, and articulatory precision while participating in the free classification task. Additionally, acoustic correlates revealed by the MDS and subjected to DFA indeed predicted listener group classification. These results beget acoustic measurement as representative of listener perception, and represent the first phase in supporting the use of a perceptually relevant taxonomy of dysarthria.
ContributorsNorton, Rebecca (Author) / Liss, Julie (Thesis advisor) / Azuma, Tamiko (Committee member) / Ingram, David (Committee member) / Arizona State University (Publisher)
Created2012
Description
Purpose: The present study examined grammatical gender use in child Spanish heritage speakers (HSs) in order to determine whether the differences observed in their grammar, when compared to Spanish monolinguals, stem from an incompletely acquired grammar, in which development stops, or from a restructuring process, in which features from the dominant and the weaker language converge to form a new grammatical system. In addition, this study evaluated whether the differences usually found in comprehension are also present in production. Finally, this study evaluates if HSs differences are the result of the input available to them.
Method: One-hundred and four typically developing children, 48 HSs and 58 monolingual, were selected based on two age groups (Preschool vs. 3rd Grade). Two comprehension and three production experimental tasks were designed for the three different grammatical structures where Spanish expresses gender (determiners, adjectives, and clitic pronouns). Linear mixed-models were used to examine main effects between groups and grammatical structures.
Results: Results from this study showed that HSs scored significantly lower than monolingual speakers in all tasks and structures; however, 3rd-Grade HSs had higher accuracy than PK-HSs. Error patterns were similar between monolinguals and HSs. Moreover, the commonly reported overgeneralization of the masculine form seems to decrease as HSs get older.
Conclusion: These results suggest that HSs’ do not face a case of Incomplete Acquisition or Restructured Grammatical gender system, but instead follow a protracted language development in which grammatical skills continue to develop after preschool years and follow the same developmental patterns as monolingual children
Method: One-hundred and four typically developing children, 48 HSs and 58 monolingual, were selected based on two age groups (Preschool vs. 3rd Grade). Two comprehension and three production experimental tasks were designed for the three different grammatical structures where Spanish expresses gender (determiners, adjectives, and clitic pronouns). Linear mixed-models were used to examine main effects between groups and grammatical structures.
Results: Results from this study showed that HSs scored significantly lower than monolingual speakers in all tasks and structures; however, 3rd-Grade HSs had higher accuracy than PK-HSs. Error patterns were similar between monolinguals and HSs. Moreover, the commonly reported overgeneralization of the masculine form seems to decrease as HSs get older.
Conclusion: These results suggest that HSs’ do not face a case of Incomplete Acquisition or Restructured Grammatical gender system, but instead follow a protracted language development in which grammatical skills continue to develop after preschool years and follow the same developmental patterns as monolingual children
ContributorsMartinez-Nieto, Lourdes (Author) / Restrepo, Maria Adelaida (Thesis advisor) / Renaud, Claire (Thesis advisor) / Pascual y Cabo, Diego (Committee member) / Thompson, Marilyn (Committee member) / Ingram, David (Committee member) / Arizona State University (Publisher)
Created2018
Description
Everyday speech communication typically takes place face-to-face. Accordingly, the task of perceiving speech is a multisensory phenomenon involving both auditory and visual information. The current investigation examines how visual information influences recognition of dysarthric speech. It also explores where the influence of visual information is dependent upon age. Forty adults participated in the study that measured intelligibility (percent words correct) of dysarthric speech in auditory versus audiovisual conditions. Participants were then separated into two groups: older adults (age range 47 to 68) and young adults (age range 19 to 36) to examine the influence of age. Findings revealed that all participants, regardless of age, improved their ability to recognize dysarthric speech when visual speech was added to the auditory signal. The magnitude of this benefit, however, was greater for older adults when compared with younger adults. These results inform our understanding of how visual speech information influences understanding of dysarthric speech.
ContributorsFall, Elizabeth (Author) / Liss, Julie (Thesis advisor) / Berisha, Visar (Committee member) / Gray, Shelley (Committee member) / Arizona State University (Publisher)
Created2014
Description
A substantial amount of research demonstrates that preschoolers' phonological awareness skills are a robust predictor of children's later decoding ability. Several investigators examined performance of children with speech sound impairment (SSI), defined as inaccurate production of speech sounds in the absence of any etiology or communication impairment, on phonological awareness tasks. Investigators found that children with SSI scored below their typically developing peers (TD) on phonological awareness tasks. In contrast, others found no differences between groups. It seems likely that differences in findings regarding phonological awareness skills among children with SSI is the fact that there is considerable heterogeneity among children with SSI (i.e., speech errors can either be a phonological or articulation). Phonology is one component of a child's language system and a phonological impairment (SSI-PI) is evident when patterns of deviations of speech sounds are exhibited in a language system. Children with an articulation impairment (SSI-AI) produce speech sound errors that are affected by the movements of the articulators, not sound patterns. The purpose of the study was to examine whether or not children with SSI-PI are at greater risk for acquiring phonological awareness skills than children with SSI-AI. Furthermore, the phonological awareness skills of children with SSI-PI and SSI-AI were compared to those of their typical peers. In addition, the role of executive function as well as the influence of phonological working memory on phonological awareness task performance was examined.
Findings indicate that the SSI-PI group performed more poorly on an assessment of phonological awareness skills than the SSI-AI and TD groups. The SSI-PI group performed significantly more poorly on tasks of executive function and phonological working memory than the TD group. The results of this study support the hypothesis that children with SSI-PI may be more vulnerable to difficulties in reading than children with SSI-AI and children with TD.
Findings indicate that the SSI-PI group performed more poorly on an assessment of phonological awareness skills than the SSI-AI and TD groups. The SSI-PI group performed significantly more poorly on tasks of executive function and phonological working memory than the TD group. The results of this study support the hypothesis that children with SSI-PI may be more vulnerable to difficulties in reading than children with SSI-AI and children with TD.
ContributorsFox, Angela Marie (Author) / Wilcox, M. Jeanne (Thesis advisor) / Ingram, David (Committee member) / Gray, Shelley (Committee member) / Connor, Carol (Committee member) / Arizona State University (Publisher)
Created2015
Description
Glottal fry is a vocal register characterized by low frequency and increased signal perturbation, and is perceptually identified by its popping, creaky quality. Recently, the use of the glottal fry vocal register has received growing awareness and attention in popular culture and media in the United States. The creaky quality that was originally associated with vocal pathologies is indeed becoming “trendy,” particularly among young women across the United States. But while existing studies have defined, quantified, and attempted to explain the use of glottal fry in conversational speech, there is currently no explanation for the increasing prevalence of the use of glottal fry amongst American women. This thesis, however, proposes that conversational entrainment—a communication phenomenon which describes the propensity to modify one’s behavior to align more closely with one’s communication partner—may provide a theoretical framework to explain the growing trend in the use of glottal fry amongst college-aged women in the United States. Female participants (n = 30) between the ages of 18 and 29 years (M = 20.6, SD = 2.95) had conversations with two conversation partners, one who used quantifiably more glottal fry than the other. The study utilized perceptual and quantifiable acoustic information to address the following key question: Does the amount of habitual glottal fry in a conversational partner influence one’s use of glottal fry in their own speech? Results yielded the following two findings: (1) according to perceptual annotations, the participants used a greater amount of glottal fry when speaking with the Fry conversation partner than with the Non Fry partner, (2) statistically significant differences were found in the acoustics of the participants’ vocal qualities based on conversation partner. While the current study demonstrates that young women are indeed speaking in glottal fry in everyday conversations, and that its use can be attributed in part to conversational entrainment, we still lack a clear explanation of the deeper motivations for women to speak in a lower vocal register. The current study opens avenues for continued analysis of the sociolinguistic functions of the glottal fry register.
ContributorsDelfino, Christine R (Author) / Liss, Julie M (Thesis advisor) / Borrie, Stephanie A (Thesis advisor) / Azuma, Tamiko (Committee member) / Berisha, Visar (Committee member) / Arizona State University (Publisher)
Created2015
Description
The purpose of this study was to identify acoustic markers that correlate with accurate and inaccurate /r/ production in children ages 5-8 using signal processing. In addition, the researcher aimed to identify predictive acoustic markers that relate to changes in /r/ accuracy. A total of 35 children (23 accurate, 12 inaccurate, 8 longitudinal) were recorded. Computerized stimuli were presented on a PC laptop computer and the children were asked to do five tasks to elicit spontaneous and imitated /r/ production in all positions. Files were edited and analyzed using a filter bank approach centered at 40 frequencies based on the Mel-scale. T-tests were used to compare spectral energy of tokens between accurate and inaccurate groups and additional t-tests were used to compare duration of accurate and inaccurate files. Results included significant differences between the accurate and inaccurate productions of /r/, notable differences in the 24-26 mel bin range, and longer duration of inaccurate /r/ than accurate. Signal processing successfully identified acoustic features of accurate and inaccurate production of /r/ and candidate predictive markers that may be associated with acquisition of /r/.
ContributorsBecvar, Brittany Patricia (Author) / Azuma, Tamiko (Thesis advisor) / Weinhold, Juliet (Committee member) / Berisha, Visar (Committee member) / Arizona State University (Publisher)
Created2017