Complex broadband sounds are decomposed by the auditory filters into a series of relatively narrowband signals, each of which conveys information about the sound by time-varying features. The slow changes in the overall amplitude constitute envelope, while the more rapid events, such as zero crossings, constitute temporal fine structure (TFS).…

Current theoretical approaches differ in their assessment of the influences of biomechanical and perceptual factors on speech production. This dissertation investigates these influences on the relative timing of the two gestures typically involved in the production of American English laterals: tongue tip raising and tongue dorsum backing.…

Although spoken word recognition is more fundamental to human communication than text recognition, knowledge of word-processing in auditory cortex is comparatively impoverished. This dissertation synthesizes current models of auditory cortex, models of cortical pattern recognition, models of single-word reading, results in phonetics and results in…

A fundamental challenge for human cognition is perceiving and acting in a world in which the statistics that characterize available sensory data are non-stationary. This thesis focuses on this problem specifically in the domain of sentence comprehension, where linguistic variability poses computational challenges to the processes underlying…

The goal of this dissertation is to examine how brain regions respond to different types of competition during word comprehension and word production. I will present three studies that attempt to enhance the current understanding of which brain regions are sensitive to different aspects of competition and how the nature of the stimuli and the…

Imitations are sophisticated performances displaying regular patterns. The study of imitation allows linguists to understand speakers' perceptions of sociolinguistic variation. In this dissertation, I analyze imitations of non-native accents in order to answer two questions: what can imitation reveal about perception, and how are "folk linguistic…

The current dissertation investigated clear speech production of Korean stops to examine the proposal that the phonetic targets of phonological categories are more closely approximated in hyperarticulated speech. The investigation also considered a sound change currently underway in Korean stops: younger speakers of the Seoul dialect produce the…

The primary aim of this dissertation was to investigate the relationship between speech perception and speech production difficulties among Japanese second language (L2) learners of English, in their learning complex syllable structures. Japanese L2 learners and American English controls were tested in a categorical ABX discrimination task of…

To what extent does language acquisition recruit domain-general processing mechanisms? In this dissertation, evidence concerning this question is garnered from the study of individual differences in infant speech perception and their predictive value with respect to language development in early childhood. In the first experiment, variation in the…