Background: Dementia is a cognitive decline that leads to the progressive deterioration of an individual's ability to perform daily activities independently. As a result, a considerable amount of time and resources are spent on caretaking. Early detection of dementia can significantly reduce the effort and resources needed for caretaking. Aims:…

Individual speakers' speech patterns differ from one another, despite presumably similar language input. What are the sources of this individual variability? In this dissertation, I explore sources of individual differences in pronunciation of coronal obstruents (/s/, /t[superscript h]/, /c[superscript h]/, /c/) at the ends of nouns in Korean.…

Purpose: Children with speech sound disorders (SSDs) often struggle with forming early representations for phonemes and words, which could impact their speech production as well as their lexical access. This difficulty may limit their ability to accurately identify nonexemplar productions of words, such as developmental misarticulations produced…

Purpose: Place and manner of articulation in American English-learning children's salient consonant-vowel-consonant-vowel (C[subscript 1]VC[subscript 2]V) target words (e.g., "baby," "bunny," and "cookie") were compared with their actual productions of these words. We hypothesized that target words with repeated place…

Purpose: Reduced use of visible articulatory information on a speaker's face has been implicated as a possible contributor to language deficits in autism spectrum disorders (ASD). We employ an audiovisual (AV) phonemic restoration paradigm to measure behavioral performance (button press) and event-related potentials (ERPs) of visual speech…

Purpose: Nonnative consonant cluster learning has become a useful experimental approach for learning about speech motor learning, and we sought to enhance our understanding of this area and to establish best practices for this type of research. Method: One hundred twenty individuals completed a nonnative consonant cluster learning task within a…

Purpose: Auditory feedback is thought to contribute to the online control of speech production. Yet, the standard method of estimating auditory feedback control (i.e., reflexive responses to auditory-motor perturbations), although sound, requires specialized instrumentation, meticulous calibration, unnatural tasks, and specific acoustic…

Purpose: The aims of this study were to analyze and characterize the "irrintzi" (a folkloric shout emitted in a single breath used by the Basque people) acoustically and to describe the mechanism by which it is emitted. Method: Thirty-six sound samples of 12 female volunteers were analyzed. Acoustic analysis included primarily…

Purpose: The spectral powers of the modulations of vocal fundamental frequency (f[subscript o]) less than 3 Hz (low-frequency power, LFP) and between 3 and 8 Hz (middle-frequency power, MFP) had been established to indicate the audiovocal feedback status and vocal efficiency of a speaker, and a resonant voice may enhance the auditory-vocal…

Turkish-speaking dyzygotic twins (n = 21) and singletons (n = 23) were tested through a standard articulation test to observe whether their consonant articulations were related to their vocabulary sizes, recorded through CDI forms, at age 3;0. Twins were observed to lag behind their singleton peers and performed below the norm level in their…

Background: Ultrasound visual biofeedback (UVBF) has the potential to be useful for the treatment of compensatory errors in speakers with cleft palate ± lip (CP±L), but there is little research on its effectiveness, or on how acceptable families find the technique. This study reports on parents' and children's perspectives on taking part in a…

Speech perception research has commonly relied on untrained listeners to provide impressionistic judgments of second language (L2) speech, and training listeners has been rare. The current study therefore explores the implications of training novice listeners (NLs) to rate accented speech. A total of 60 listeners were recruited, 30 who remained…

Substantial evidence exists suggesting that access to articulatory gestures during instruction improves students' phonological awareness skills, but researchers have yet to explore the role of articulatory gestures in initial phonics instruction. The purpose of this study was to examine if visual access to articulatory gestures (i.e., mouth cues)…

Purpose: The aim of this study was to explore relations between speech sound disorder severity and selective mutism in a group of children with 7q11.23 duplication syndrome (Dup7), a genetic condition predisposing children to childhood apraxia of speech (CAS) and other speech sound disorders and to anxiety disorders, including selective mutism and…

I investigate the acquisition of affrication in Québec French (QF), where affricates are in complementary distribution with coronal stops, being realized before high front vowels and glides. Previous research on other languages shows that affricates are acquired before branching onsets, which supports the idea that complexity at the level of the…