Although extensive research has focused on the perceptual abilities of second language (L2) learners, a significant gap persists in understanding how cognitive functions like phonological short-term memory (PSTM) and nonverbal intelligence (IQ) impact L2 speech perception. This study sets out to investigate the discrimination of L2 English…

Upon acquiring or learning another language, cross-linguistic influence (CLI) is an inevitable phenomenon with which a bilingual speaker lives. One key aspect of CLI is its bidirectionality, flowing between both the first (L1) and second languages (L2) mutually affecting each other. However, investigations of L1 CLI on L2 have dominated previous…

Purpose: Growing evidence supports the inclusion of perceptual tests that quantify the processing of temporal fine structure (TFS) in clinical hearing assessment. Many tasks have been used to evaluate TFS in the laboratory that vary greatly in the stimuli used and whether the judgments require monaural or binaural comparisons of TFS. The purpose…

Purpose: Developmental language disorder (DLD), an unexplained problem using and understanding spoken language, has been hypothesized to have an underlying auditory processing component. Auditory feedback plays a key role in speech motor control. The current study examined whether auditory feedback is used to regulate speech production in a…

Purpose: This research compared individuals from two first language (L1) backgrounds (English and Japanese) to determine how they may differ in their perception of Mandarin tones (Tones 1 vs. 2 [T1-T2], Tones 1 vs. 3 [T1-T3], Tones 1 vs. 4 [T1-T4], Tones 2 vs. 3 [T2-T3], Tones 2 vs. 4 [T2-T4], Tones 3 vs. 4 [T3-T4]) on account of their L1. Method:…

The present dissertation analyzed speech production and perception in early heritage Spanish-English bilingual children. Specifically, I investigated how perception and production of lexical stress develops in bilingual children. Current models of second language (L2) speech perception do not include heritage bilinguals or suprasegmental aspects…

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 study investigated the developmental trajectories of three perceptual domains related to regional dialect competence: the linguistic domain, tested through an intelligibility in noise task; the objective indexical domain, tested through locality judgments and a free classification task; and the subjective indexical domain, tested through…

Previous research has shown that an increased second language (L2) vocabulary size leads to better attunement to the cues required to distinguish L2 contrastive phones. This has been the central tenet of the vocabulary-tuning model (vocab) on the basis of evidence by Japanese learners of English in Australia. We aim to test the validity of the…

We developed a computerized audiovisual training programme for school-aged children with specific language impairment (SLI) to improve their phonological skills. The programme included various tasks requiring phonological decisions. Spoken words, pictures, letters and written syllables were used as training material. Spoken words were presented…

Purpose: Several investigators have compared infants' detection of speech in speech and nonspeech maskers to evaluate developmental differences in masking. Such comparisons have produced contradictory results, possibly because each investigation used different stimuli. The current study examined target and masker effects on infants' and adults'…

Task-irrelevant speech impairs short-term serial recall appreciably. On the interference-by-process account, the processing of physical (i.e., precategorical) changes in speech yields order cues that conflict with the serial-ordering process deployed to perform the serial recall task. In this view, the postcategorical properties (e.g., phonology,…

Language experience shapes infants' abilities to process speech sounds, with universal phonetic discrimination abilities narrowing in the second half of the first year. Brain measures reveal a corresponding change in neural discrimination as the infant brain becomes selectively sensitive to its native language(s). Whether and how bilingual…

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…

While it is well established that non-native speakers differ from native speakers in their perception and/or production of Mandarin lexical tones, empirical studies focusing on non-native "learners" are still limited. The objective of this study is to add to the current understanding of lexical tone perception by comparing native…