Purpose: Item response theory (IRT) is a psychometric approach to measurement that uses latent trait abilities (e.g., speech sound production skills) to model performance on individual items that vary by difficulty and discrimination. An IRT analysis was applied to preschoolers' productions of the words on the Goldman-Fristoe Test of…

Instruction in second language (L2) English phoneme pronunciation almost invariably includes a focus on improving the learners' use of their articulatory organs to pronounce the relevant sounds. However, the pronunciation of many English sounds also relies on effort from the abdominal region, and under-utilization of this region can often…

Purpose: This study assessed the role of spectro-temporal modulation cues in the discrimination of 2 phonetic contrasts (voicing and place) for young infants. Method: A visual-habituation procedure was used to assess the ability of French-learning 6-month-old infants with normal hearing to discriminate voiced versus unvoiced (/aba/-/apa/) and…

Purpose: Most research examining long-term-memory effects on nonword repetition (NWR) has focused on lexical-level variables. Phoneme-level variables have received little attention, although there are reasons to expect significant sublexical effects in NWR. To further understand the underlying processes of NWR, this study examined effects of…

Purpose: The purpose of this study was to examine cognitive flexibility for semantic and perceptual information in preschool children who stutter (CWS) and who do not stutter (CWNS). Method: Participants were 44 CWS and 44 CWNS between the ages of 3;0 and 5;11 (years;months). Cognitive flexibility was measured using semantic and perceptual…

Purpose: The goal of this study was to better understand how and when onset /l/ ("leap") and coda /l/ ("peel") are acquired by children by examining both the articulations involved and adults' perceptions of the produced segments. Method: Twenty-five typically developing Australian English-speaking children aged 3;0…

Recently, several studies have argued that infants capitalize on the statistical properties of natural languages to acquire the linguistic structure of their native language, but the kinds of constraints which apply to statistical computations remain largely unknown. Here we explored French-learning infants' perceptual preference for…

Research attempting to understand the intermediate stages of first-language acquisition and disordered speech has led to the discovery of covert contrast. A covert contrast is a statistically reliable difference between phonemes that is produced by a language learner, but in a way that cannot be heard readily by a listener of the target language.…

Purpose: The purpose of this study was to determine the effects of biofeedback on control of nasalization in individuals with typical speech. Method: Forty-eight individuals with typical speech attempted to increase and decrease vowel nasalization. During training, stimuli consisted of consonant-vowel-consonant (CVC) tokens with the center vowels…

Purpose The aims of the present study are (a) to quantify the developmental sequence of fricative mastery in Putonghua-speaking children and discuss the observed pattern in relation to existing theoretical positions, and (b) to describe the acquisition of the fine-articulatory/acoustic details of fricatives in the multidimensional acoustic space.…

Brazilian Portuguese allows only /s, N, l, r/ syllable finally, and of these, only /s/ is realized faithfully (as well as /r/ for some speakers). In order to avoid unacceptable codas, dialects of Brazilian Portuguese employ such strategies as epenthesis, nasal absorption, debucalization, and gliding. The current analysis argues that codas in…

This study addressed two areas of inquiry: 1) the influence of enlisting three underlying cognitive learning processes (CLPs) in alphabet learning, and 2) order effects for letter name and letter sound instruction. Alphabet instruction was designed to enlist Paired Associate Learning (PAL) only, PAL plus Orthographic Learning (OL), or PAL plus…

As part of a research project on the investigation of second language (L2) ultimate attainment in 41 Spanish early and late near-native speakers of L2 Swedish, the present study reports on voice onset time (VOT) analyses of the production of Swedish word-initial voiceless stops, /p t k/. Voice onset time is analyzed in milliseconds as well as in…

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…

Research involving stuttering in multilingual individuals is limited. Speech-language therapists face the challenge of treating a diverse client base, which includes multilingual individuals. The aim of this study was to examine the stuttering moments across English, Afrikaans, and German in a multilingual speaker. A single multilingual adult with…