Speech is highly variable and systematic, governed by the internal linguistic system and socio-indexical factors. The systematic relationship of socio-indexical factors and variable phonetic forms, referred to here as "socio-indexical structure," has been the cornerstone of sociophonetic research over the last several decades. Research…

Dialects vary in their allophonic patterns, which can affect listeners' phonological and lexical representations. I explore how different exposure to dialect-specific allophonic patterns for two vowels in American English, /ae ai/, affects listeners' lexical processing behaviors across three perception tasks: perceptual similarity, priming, and…

Second language (L2) learners often have difficulty perceiving L2 sound contrasts when the first-language (L1) and L2 sounds are acoustically similar and these similar L2 sounds correspond to an existing L1 sound (Flege, 1995). To improve L2 learners' perception of sound contrasts, researchers have used high-variability phonetic training (HVPT)…

This dissertation investigated how four factors -- the degree of L2 experience, L1 sound structure, age difference in L1 language development and age of L2 exposure -- affect the perceptual cue weighting of duration and spectral differences for English tense-lax vowel contrasts. Four major hypotheses were tested: desensitization hypothesis (DH)…

The present study investigates the time course of acoustic cue integration in the processing of the Korean three-way laryngeal stop contrast by native Korean listeners and English second language (L2) learners of Korean. As such, this study seeks to understand how native listeners and L2 learners weight and integrate fine-grained acoustic…

Arabic emphasis refers to the production of consonants resulting from a primary constriction in the dental or alveolar region and a secondary constriction in the back of the vocal tract, recognized as 'Emphatic.' These have contrastive consonants produced in the dental or alveolar region, recognized as 'Plain.' The existing research on emphasis in…

The present dissertation explores the effect of exposure to non-native speech via foreign film on non-native speech production and perception. In order to explore potential effects, two main experiments were developed, which examined French production and perception by monolingual native speakers of English before and after exposure to French…

Spoken words vary phonetically along a number of dimensions, such as duration, pitch, and vowel quality. Much of this variation is associated with social factors like the dialect, age, or gender of the speaker -- a type of variation termed 'socio-indexical'. Traditional theories of speech perception have seen this socio-indexical variation as a…

This study aimed to investigate the role that phonetic convergence plays in the acquisition of L2 segments. In particular, it examined whether phonetic convergence towards native speakers could help Arabic-speaking second-language (L2) learners of English improve their pronunciation of four problematic English segments (/p, v, [open-mid front…

This dissertation presents three studies that examined issues related to the production and the perception of pitch in a tone language. The first study examined linguistic contexts that may modulate consonant-induced pitch perturbations (CF0) in a tone language. Previous studies have produced mixed findings regarding the role of linguistic…

This dissertation research examines the acquisition of second language vowels. For second language learners, learning a new languages' sound inventory, particularly its vowels, presents a challenge perceptually and in terms of production. Incorrectly perceiving and producing sounds in a second language results in a foreign accent in many adult…

This work examines the link between low-level cortical acoustic processing and higher-level cortical phonemic processing. Specifically, using functional magnetic resonance imaging, it looks at 1) whether or not the vowels [alpha] and [i] are distinguishable in regions of interest defined by the first two resonant frequencies (formants) of those…

A great deal of the research on cross-linguistic phonetic influence demonstrates that a speaker's knowledge of their first language (L1) significantly affects their ability to perceive and produce sounds in any other language. While current studies show that cross-linguistic transfer occurs at the L3 level, some research suggests that properties…

Increasing numbers of Hispanic immigrants are entering the US (US Census Bureau, 2011) and are learning American English (AE) as a second language (L2). Many may experience difficulty in understanding AE. Accurate perception of AE vowels is important because vowels carry a large part of the speech signal (Kewley-Port, Burkle, & Lee, 2007). The…

A fundamental issue in speech science concerns the extent to which speech sounds are mentally represented by articulatory-motor and/or auditory-acoustic features. This dissertation aims to expand upon the current literature by investigating changes in production and perception following visual feedback training with either articulatory or acoustic…