This dissertation examines whether EFL and ESL Korean learners of English are able to produce and perceive two English phonological contrasts that depend on vowel duration differences, coda consonant voicing contrasts and the tense-lax distinction in vowels. For production, it examines differences in vowel duration and vowel quality associated…

Although second language (L2) learners often have difficulty with learning the L2 pronunciation, the literature has reported a mix of more successful and less successful learners. Many factors could contribute to individual variation in L2 speech sound learning. This dissertation examines a few factors that are hypothesized to influence L2…

The goal of this dissertation is to better understand the targets of vowels in speech production. Three experiments investigate vowel production in non-native speech, probing how new vowel categories, and thus targets, are formed. Three research questions are addressed: (1) Do vowels have articulatory targets (as predicted by Browman &…

Previous studies on second language (L2) phonetic acquisition in early bilingual learners have mainly examined immigrants to the L2 country; however, with recent growing dual-language immersion programs, the immersed bilingual group emerged and required more attention in the research. This study aims to investigate vowel patterns of young…

The current study explored individual differences in sensitivity to sub-phonemic variation of acoustic cues in the perception of a native language (L1) category in order to test the hypothesis that second language (L2) learners' different sensitivity to the L2-relevant acoustic dimension in L1 perception could explain individual variability in…

The dissertation explored the effectiveness of perceptual training with English for Speakers of Other Languages (ESOL), for both the perception and production of three problematic vowel contrasts, /ae/-/[open-mid front unrounded vowel]/, /[near-close near-front unrounded vowel]/-/[open-mid front unrounded vowel]/, /[near-close near-front unrounded…

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)…

The current study investigated the nature of second language (L2) learning influence on first language (L1) production and perception by systematically examining several L1 and L2 related factors (L1:L2 relative dominance, L2 production and perception acuity, and learning context) and their effect on L1 change. It is the first of its kind in…

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…

Previous literature has shown that voicing contrast is a difficult feature for Chinese-English emergent bilingual learners of L3 Spanish (Bravo Diaz, 2020; Chen, 2007; Zhang, 2022). The production of voicing contrast in stops has been broadly investigated in second and third language studies (e.g., Zampini, 1998; Llama, 2010; Wrembel, 2014), but…

This dissertation analyzes the production and perception of lexical stress in trilinguals' first, second, and third languages (L1, L2, and L3) to evaluate how the cue-weighting transfer hypothesis applies to L3 acquisition. According to this hypothesis, acoustic cues to stress have different weights across languages, and results from both…

This dissertation investigated the acoustic and articulatory correlates of lexical stress in Mandarin second language (L2) learners of English, as well as in first language (L1) speakers. The present study used a minimal pair respective to stress location (e.g., OBject versus obJECT) obtained from a publicly available Mandarin Accented English…