Hearing & Speech Sciences Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/2776
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Item UNDERSTANDING HOW AFRICAN AMERICAN ENGLISH-SPEAKING CHILDREN USE INFLECTIONAL VERB MORPHOLOGY IN SENTENCE PROCESSING AND WORD LEARNING(2024) Byrd, Arynn S; Edwards, Jan; Huang, Yi Ting; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This research examined how linguistic differences between African American English (AAE) and Mainstream American English (MAE) impact how children process sentences and learn new information. The central hypothesis of this dissertation is that these linguistic differences adversely impact how AAE-speaking children use contrastive inflectional verb morphology (e.g., was/were, third person singular -s) to process and comprehend MAE sentences, as well as to infer word meanings when they depend on dialect-specific parsing of sentence cues. To test this hypothesis, this dissertation conducted three experiments on how linguistic mismatch impacts spoken language comprehension and word learning in school-age MAE- and AAE-speaking children. The first study examined how children used the auxiliary verbs was or were to comprehend MAE sentences in an offline spoken language comprehension task. In contrast, the second study asked the same question in an online sentence processing task. The final study examined how children used inflectional verb morphology (i.e., third-person singular -s, was/were) to infer information about novel verbs. Each study examined how participants’ dialect, either MAE or AAE, predicted performance on listening tasks produced in MAE. Furthermore, each study examined how individual differences such as age, dialect density, and vocabulary size influenced children’s performance.Across all studies, results demonstrated that when there were redundant linguistic cues that were not impacted by dialect differences, AAE- and MAE-speaking children used available linguistic cues to process and comprehend spoken language and infer verb meanings in a similar manner. However, when linguistic redundancy was decreased due to perceptual ambiguity, there were group differences in how AAE- and MAE-speaking children used inflectional verb morphology on spoken language tasks. The second study showed that AAE-speaking children were sensitive to contrastive verb morphology in real-time processing, but they were less likely than their MAE-speaking peers to use it as an informative cue to revise initial parses when processing spoken language. The results of the final study indicated that individual characteristics such as age and dialect density influence how dialect impacts a learning process. These results demonstrate that linguistic mismatch can affect spoken language processes. Furthermore, the findings from this research highlight a complex relationship between the effects of linguistic mismatch and individual differences such as age and dialect density.Item ISOLATING EFFECTS OF PERCEPTUAL ANALYSIS AND SOCIOCULTURAL CONTEXT ON CHILDREN’S COMPREHENSION OF TWO DIALECTS OF ENGLISH, AFRICAN AMERICAN ENGLISH AND GENERAL AMERICAN ENGLISH(2023) Erskine, Michelle E; Edwards, Jan; Huang, Yi Ting; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)There is a long-standing gap in literacy achievement between African American and European American students (e.g., NAEP, 2019, 2022). A large body of research has examined different factors that continue to reinforce performance differences across students. One variable that has been a long-term interest to sociolinguists and applied scientists is children’s use of different dialects in the classroom. Many African American students speak African American English (AAE), a rule-governed, but socially stigmatized, dialect of English that differs in phonology, morphosyntax, and pragmatics from General American English (GAE), the dialect of classroom instruction. Empirical research on dialect variation and literacy achievement has demonstrated that linguistic differences between dialects make it more difficult to learn to read (Buhler et al., 2018; Charity et al., 2004; Gatlin & Wanzek, 2015; Washington et al., 2018, inter alia) and recently, more difficult to comprehend spoken language (Byrd et al., 2022, Edwards et al., 2014; Erskine, 2022a; Johnson, 2005; de Villiers & Johnson, 2007; JM Terry, Hendrick, Evangelou, et al., 2010; JM Terry, Thomas, Jackson, et al., 2022). The prevailing explanation for these results has been the perceptual analysis hypothesis, a framework that asserts that linguistic differences across dialects creates challenges in mapping variable speech signals to listeners’ stored mental representations (Adank et al., 2009; Clopper, 2012; Clopper & Bradlow, 2008; Cristia et al., 2012). However, spoken language comprehension is more than perceptual analysis, requiring the integration of perceptual information with communicative intent and sociocultural information (speaker identity). To this end, it is proposed that the perceptual analysis hypothesis views dialect variation as another form of signal degradation. Simplifying dialect variation to a signal-mapping problem potentially limits our understanding of the contribution of dialect variation to spoken language comprehension. This dissertation proposes that research on spoken language comprehension should integrate frameworks that are more sensitive to the contributions of the sociocultural aspects of dialect variation, such as the role of linguistic and nonlinguistic cues that are associated with speakers of different dialects. This dissertation includes four experiments that use the visual world paradigm to explore the effects of dialect variation on spoken language comprehension among children between the ages of 3;0 to 11;11 years old (years;months) from two linguistic communities, European American speakers of GAE and African American speakers with varying degrees of exposure to AAE and GAE. Chapter 2 (Erskine [2022a]) investigates the effects of dialect variation in auditory-only contexts in two spoken word recognition tasks that vary in linguistic complexity: a) word recognition in simple phrases and b) word recognition in sentences that vary in semantic predictability. Chapter 3 [Erskine (2022b)] examine the effects of visual and auditory speaker identity cues on dialect variation on literal semantic comprehension (i.e., word recognition in semantically facilitating sentences). Lastly, Chapter 4 [Erskine (2022c)] examines the effects of visual and auditory speaker identity cues on children’s comprehension of different dialects in a task that evaluates pragmatic inferencing (i.e., scalar implicature). Each of the studies investigate the validity of the perceptual analysis against sociolinguistcally informed hypotheses that account for the integration of linguistic and nonlinguistic speaker identity cues as adequate explanations for relationships that are observed between dialect variation and spoken language comprehension. Collectively, these studies address the question of how dialect variation impacts spoken language comprehension. This dissertation provides evidence that traditional explanations that focus on perceptual costs are limited in their ability to account for correlations typically reported between spoken language comprehension and dialect use. Additionally, it shows that school-age children rapidly integrate linguistic and nonlinguistic socioindexical cues in ways that meaningfully guide their comprehension of different speakers. The implication of these findings and future research directions are also addressed within.Item Examining Narrative Language in Early Stage Parkinson's Disease and Intermediate Farsi-English Bilingual Speakers(2022) Lohrasbi, Bushra; Faroqi-Shah, Yasmeen; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This study aimed to examine procedural aspects of language (grammaticality, syntactic complexity, regular past tense verb production), verb use, and the association between motor-speech, language abilities, and intelligibility in Early Stage Parkinson's Disease (PD) and Intermediate Farsi-English Bilingual Speakers (L2). Ullman’s Declarative-Procedural Model (2001) provided this study with a dual-mechanism model that justified a theoretical comparison between these two populations. Twenty-four neurologically healthy native speakers of English, twenty-three Parkinson’s Disease participants, and thirteen bilingual Farsi-English speakers completed three narrative picture description tasks and read the first three sentences of the Rainbow Passage. Language samples were transcribed and analyzed to derive measures of morphosyntax and verb use, including grammatical accuracy, grammatical complexity, and proportions of regular past tense, action verbs and light verbs. The results did not show any evidence of morphosyntactic or action verb deficit in PD. Neither was there any evidence of a trade-off between morphosyntactic performance and severity of speech motor impairment in PD. L2 speakers had lower scores on grammatical accuracy and a measure of morphosyntactic complexity, but did not differ from monolingual speakers on measures of verb use. Overall, these results show that language abilities (morphosyntax and verb use) are preserved in early stage PD. This study replicates the well-documented finding that morphosyntax is particularly challenging for late bilingual speakers. The results did not support Ullman’s Declarative-Procedural (2001) hypothesis of language production in Parkinson’s Disease or L2 speakers.Item SPECTRAL CONTRASTS PRODUCED BY CHILDREN WITH COCHLEAR IMPLANTS: INVESTIGATING THE IMPACT OF SIGNAL DEGRADATION ON SPEECH ACQUISITION(2022) Johnson, Allison Ann; Edwards, Jan; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The primary objective of this dissertation was to assess four consonants, /t/, /k/, /s/, and /ʃ/, produced by young children with cochlear implants (CIs). These consonants were chosen because they comprise two place-of-articulation contrasts, which are cued auditorily by spectral information in English, and they cover both early-acquired (/t/, /k/) and late-acquired (/s/, /ʃ/) manners of articulation. Thus, the auditory-perceptual limitations imposed by CIs is likely to impact acquisition of these sounds: because spectral information is particularly distorted, children have limited access to the cues that differentiate these sounds.Twenty-eight children with CIs and a group of peers with normal hearing (NH) who were matched in terms of age, sex, and maternal education levels participated in this project. The experiment required children to repeat familiar words with initial /t/, /k/, /s/, or /ʃ/ following an auditory model and picture prompt. To create in-depth speech profiles and examine variability both within and across children, target consonants were elicited many times in front-vowel and back-vowel contexts. Patterns of accuracy and errors were analyzed based on transcriptions. Acoustic robustness of contrast was analyzed based on correct productions. Centroid frequencies were calculated from the release-burst spectra for /t/ and /k/ and the fricative noise spectra for /s/ and /ʃ/. Results showed that children with CIs demonstrated patterns not observed in children with NH. Findings provide evidence that for children with CIs, speech acquisition is not simply delayed due to a period of auditory deprivation prior to implantation. Idiosyncratic patterns in speech production are explained in-part by the limitations of CI’s speech-processing algorithms. The first chapter of this dissertation provides a general introduction. The second chapter includes a validation study for a measure to differentiate /t/ and /k/ in adults’ productions. The third chapter analyzes accuracy, errors, and spectral features of /t/ and /k/ across groups of children with and without CIs. The fourth chapter analyzes /s/ and /ʃ/ across groups of children, as well as the spectral robustness of both the /t/-/k/ and the /s/-/ʃ/ contrasts across adults and children. The final chapter discusses future directions for research and clinical applications for speech-language pathologists.Item Automatic Syntactic Processing in Agrammatic Aphasia: The Effect of Grammatical Violations(2020) Kim, Minsun; Faroqi-Shah, Yasmeen; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This study aimed to examine syntactic processing in agrammatic aphasia. We hypothesized that agrammatic individuals’ automatic syntactic processing would be preserved, as measured by word monitoring task, and their knowledge of syntactic constraints would be impaired, as measured by sentence judgment task, and their performance would vary by type of syntactic violation. The study found that the sentence processing in agrammatism differed based on the type of violation in both tasks: preserved for semantic and tense violations and impaired for word category violations. However, there was no correlation between the two tasks. Furthermore, single-subject analyses showed that automatic syntactic processing for word category violations does not seem to be impaired in aphasia. Based on the findings, this study supports that knowledge of syntactic constraints and automatic processing may be relatively independent abilities which are not related. Findings suggest that individuals with agrammatic aphasia may have preserved automatic syntactic processing.