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…

The role of the right hemisphere in phonetic processing is thought to be relatively minimal, at least in comparison to the role of the left hemisphere. However, the right hemisphere is known to play a critical role in vocal identity processing, a fact that is striking given that the acoustic-phonetic details of the speech signal can differ…

The Perceptual Assimilation Model (PAM) (Best, 1995) claims listeners directly perceive articulatory gestures of the vocal tract rather than acoustic/auditory signals. Accordingly, the articulatory similarities and discrepancies between native and non-native sounds determine the perceptual assimilation patterns of non-native sounds. This study…

This study investigates the effects of native language experience and phonetic properties on the discrimination of labial-velar versus labial and velar contrasts, as well as voicing contrasts in labials, velars, and labial-velars. Research indicates that phonological perceptions are influenced by native language experience and the specific…

In speech perception tasks with ambiguous bottom-up information, lexical processes have been shown to influence listener responses, such as in phoneme categorization tasks (Ganong, 1980). Proponents of interactive theories of speech perception and spoken word recognition assert this influence is a top-down feedback mechanism that can affect…

This study investigates acoustically one of long-term debated phonetic characteristics, the so-called Arabic voiced pharyngeal fricative /[voiced pharyngeal fricative]/. Most recent studies have found the Arabic pharyngeal to be approximant, while others have categorized it as a stop in careful speech, and still others have suggested it is a…

The research includes three studies at the intersection of communications disorders and computational linguistics. We begin with the case study of APTgt, a system created to improve reinforcement for Phonetics students and improve Linguistic tools for their instructions. A portion of this system utilizes machine learning techniques (i.e.,…

Listeners selectively tune in to the most relevant cues for contrasting sounds, and this process impacts their perceptual sensitivity to these cues (Nosofsky, 1986; Pisoni, 1991). For bilingual listeners, recent work suggests a shared L1/L2 phonology system with the phonetic properties of each sound established in a language-specific way…

With the increasing prevalence of autism diagnoses globally, the overall aim of this dissertation is to improve our understanding of the linguistic aptitude of autistic individuals. Given that the autism diagnosis is a spectrum, we rely on the Autism Quotient (AQ) test, which measures the quantity of autistic-like traits an individual possesses,…

Vowel nasalization usually occurs through a two-step process whereby a vowel is nasalized via coarticulation with a nearby nasal segment; when the language later drops the nasal segment, a nasal vowel remains. Spontaneous vowel nasalization is a rare, peculiar form of nasalization that emerges in contexts that lack an historical etymological nasal…

Language learners need to map a continuous, multidimensional acoustic signal to discrete abstract speech categories. The complexity of this mapping poses a difficult learning problem, particularly for second language learners who struggle to acquire the speech sounds of a non-native language, and almost never reach native-like ability. A common…

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…

This mixed methods cross-sectional survey study framed in amalgamation theory (Ehri, 2020) and the Simple View of Reading (Gough & Tunmer, 1986) explored the ways in which k-2 general classroom teachers define, understand, and teach sight word development through an orthographic mapping lens. The study utilized a convergent parallel design to…

This dissertation investigates language-specific acoustic and aerodynamic phenomena in language contact situations. Whereas most work on second language and bilingual phonology has focused on individual consonants and vowels, this project examines patterns of coarticulation in the two languages of Spanish-English and French-English bilingual…