Individual speakers' speech patterns differ from one another, despite presumably similar language input. What are the sources of this individual variability? In this dissertation, I explore sources of individual differences in pronunciation of coronal obstruents (/s/, /t[superscript h]/, /c[superscript h]/, /c/) at the ends of nouns in Korean.…

With the rise of bilinguals globally, extensive research has been conducted to understand how bilingualism affects cognitive functions differently from monolingualism, with significant implications for bilingual education, healthcare, and other fields. Specific to language processing, differences have been identified between second language (L2)…

Speech is a complex, redundant and variable signal happening in a noisy and ever changing world. How do listeners navigate these complex auditory scenes and continuously and effortlessly understand most of the speakers around them? Studies show that listeners can quickly adapt to new situations, accents and even to distorted speech. Although prior…

The process of spoken word recognition is influenced by both bottom-up sensory information and top-down cognitive information. These cues are used to process the phonological and semantic representations of speech. Several studies have used EEG/ERPs to study the neural mechanisms of children's spoken word recognition, but less is known about the…

The role of the right hemisphere in phonetic processing is thought to be relatively minimal, at least in comparison to the role of the left hemisphere. However, the right hemisphere is known to play a critical role in vocal identity processing, a fact that is striking given that the acoustic-phonetic details of the speech signal can differ…

Due in part to its complex nature, there is still much to uncover in the investigation of the neural processes that contribute to synchronization between speakers and listeners during communication in the context of social cognition, specifically between native and nonnative English speakers and listeners. This study used a novel method of…

In communication between first (L1) and second (L2) language users, the default has long been for L2 speakers to assume most, if not all, responsibility for adjusting their speech to accommodate their interlocutor. This not only places an undue burden on the speaker, but also furthers the assumption of listener passivity in communication. One…

Evidence from neuropsychological studies of individuals with brain damage post-stroke has supported the separation of working memory (WM) capacities for semantic (word meaning) and phonological (speech sound) information. These separate capacities have been shown to play different roles in supporting multiword language production, with semantic WM…

The perception and encoding of voice cues in consonants have been well studied, whereas there has been relatively little research on aspiration. The current study examined the encoding and perception of aspiration and voicing in Hindi, American English, and Tamil listeners when relevant cues were and were not degraded by noise. This study is novel…

Clear speech is a speaking style that has been shown to improve intelligibility in adverse listening conditions, for various listener and talker populations. Clear-speech phonetic enhancements include a slowed speech rate, expanded vowel space, and expanded pitch range. Although clear-speech phonetic enhancements have been demonstrated across a…

Choosing specific implementational details is one of the most important aspects of creating and evaluating a model. In order to properly model cognitive processes, choices for these details must be made based on empirical research. Unfortunately, modelers are often forced to make decisions in the absence of relevant data. My work investigates the…

Models of speech perception suggest a dorsal stream connecting the temporal and inferior parietal lobe with the inferior frontal gyrus. This stream is thought to involve an auditory motor loop that translates acoustic information into motor/articulatory commands and is further influenced by decision making processes that involve maintenance of…

Real-time use of spoken language is a fundamentally interactive process involving speech perception, speech production, linguistic competence, motor control, neurocognitive abilities such as working memory, attention, and executive function, environmental noise, conversational context, and--critically--the communicative interaction between…

This dissertation proposes a dynamical computational model of the timecourse of phonological parameter setting. In the model, phonological representations embrace phonetic detail, with phonetic parameters represented as activation fields that evolve over time and determine the specific parameter settings of a planned utterance. Existing models of…

References that speakers make can include both "conceptual information," which contributes to explicatures, and "procedural information," which constrains explicatures (Wilson & Sperber 1993). The current study compares the references made by autistic and typically developing children in naturally occurring conversational…