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…

Purpose: This study investigated the efficacy of ultrasound biofeedback compared to a traditional acoustic input-only method in the second-language (L2) production training of English tense-lax vowel contrasts (/i-[near-close near-front unrounded vowel]/ and /e-[open-mid front unrounded vowel]/). The relationship between the degrees of production…

To become a native speaker, beyond obligatory rules, children need to learn systematic variation in the language, as it is present at all levels of language structure and is an integral part of linguistic knowledge. To give an example in English, speakers sometimes pronounce words ending in -ing with -in' (e.g., working vs. workin') depending on…

Purpose: This study aimed to (a) relate temporal patterning of articulation to functional speech outcomes in neurologically healthy and impaired speakers, (b) identify changes in temporal patterning of articulation in neurologically impaired speakers, and (c) evaluate how these changes can be modulated by speaking rate manipulation. Method:…

Purpose: The purpose of this study was to investigate how the distinctive establishment of 2nd language (L2) vowel categories (e.g., how distinctively an L2 vowel is established from nearby L2 vowels and from the native language counterpart in the 1st formant [F1] × 2nd formant [F2] vowel space) affected L2 vowel perception. Method: Identification…

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…

This dissertation examines the development of the internal structure of the Korean syllable by adult Korean learners whose native language is English. Prior research has identified the prominence of the body constituent in Korean and the rime constituent in English. The current study focuses on the acquisition of the body unit by English speakers…

In learning language, children must discover how to interpret the linguistic significance of phonetic variation. On some accounts, receptive phonology is grounded in perceptual learning of phonetic categories from phonetic distributions drawn over the infant's sample of speech. On other accounts, receptive phonology is instead based on phonetic…

Purpose: We investigated whether rhythm discrimination is mainly driven by the native language of the listener or by the fundamental design of the human auditory system and universal cognitive mechanisms shared by all people irrespective of rhythmic patterns in their native language. Method: In multiple experiments, we asked participants to listen…

This study examines whether Japanese native (L1) listeners can implicitly learn stress pattern regularities, not present in their L1, after a brief auditory exposure. In the exposure phase, the participants listened to and repeated words bearing stress patterned after Latin, but with a highly restricted consonant inventory. They performed a…

The speech of second language learners is often influenced by phonetic patterns of their first language. This can make them difficult to understand, but sometimes for listeners of the same first language to a lesser extent than for native listeners. The present study investigates listeners' awareness of the accent by asking whether accented speech…

Perceptual assimilation is a well-known task; however, there is no study on the assimilation pattern of the English monophthongs by L2 Thai learners. The aims of this study are to explore the perceptual assimilation patterns of the British English monophthongs to Thai monophthongs by L2 Thai learners and to examine the effect of L2 experience on…

Purpose: The objective was to investigate acoustic cue processing in lexical-tone recognition by pediatric cochlear-implant (CI) recipients who are native Mandarin speakers. Method: Lexical-tone recognition was assessed in pediatric CI recipients and listeners with normal hearing (NH) in 2 tasks. In Task 1, participants identified naturally…

This dissertation begins with the observation of a typological asymmetry within phonological patterns related to phonetic naturalness. Patterns that are rooted within existing tendencies of perception and/or production--in other words, patterns that are phonetically "natural"--are common in phonological typology and seen in a variety of…