Across languages, certain syllables are systematically preferred to others (e.g., "plaf > ptaf"). Here, we examine whether these preferences arise from motor simulation. In the simulation account, ill-formed syllables (e.g., "ptaf") are disliked because their motor plans are harder to simulate. Four experiments compared…

This dissertation examines how listeners' knowledge of interspeaker variability guides their generalization of perceptual learning in multi-talker listening. A series of perceptual learning experiments are conducted to evaluate whether listeners generalize what they have learned about a previous talker's production of sibilants and stop VOT to…

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…

Language has a rhythmic structure, but little is known about the mechanisms that underlie how it is planned. Traditional models of language production assume that metrical and segmental planning occur independently and in parallel (Roelofs & Meyer, 1998). We test this claim in three experiments. In Experiment 1, participants completed an…

There is no one-to-one mapping between speech acoustics and individual speech sounds; instead, the acoustic cues produced for individual speech sounds show wide variability both within and across talkers. Nonetheless, listeners perceive the speech of familiar and novel talkers with ease. It is theorized that listeners achieve this feat by…

Purpose: The aim of this study was to characterize speech acoustics in bilingual preschoolers who speak Jamaican Creole (JC) and English. We compared a standard approach with a culturally responsive approach for characterizing speech sound productions. Preschoolers' speech productions were compared to adult models from the same linguistic…

The perception and encoding of voice cues in consonants have been well studied, whereas there has been relatively little research on aspiration. The current study examined the encoding and perception of aspiration and voicing in Hindi, American English, and Tamil listeners when relevant cues were and were not degraded by noise. This study is novel…

Auditory speech appears to be linked to visual articulatory gestures and orthography through different mechanisms. Yet, both types of visual information have a strong influence on speech processing. The present study directly compared their contributions to speech processing using a novel word learning paradigm. Native speakers of French, who were…

Purpose: As a class, fricatives are more "resistant" to consonant-vowel coarticulation than other English sounds. This study investigates the relative coarticulatory resistance of /[voiceless dental fricative], s, [voiceless palato-alveolar fricative]/ in child and adult speech to better understand the acquisition of individuated speech…

This study investigated the role of cross-linguistic similarity in the acquisition of Russian initial stop contrasts by Chinese learners, addressing two specific research questions: (1) How similar are Russian voiced stops to Mandarin stops for Chinese learners?; and (2) How can the speech learning model (SLM) be applied to account for the…

Purpose: This study aimed to identify predictors of response to treatment for residual speech sound disorder (RSSD) affecting English rhotics. Progress was tracked during an initial phase of traditional motor-based treatment and a longer phase of treatment incorporating ultrasound biofeedback. Based on previous literature, we focused on baseline…

An ongoing debate in phonology concerns the extent to which the phonological typology is shaped by synchronic learning biases. The two best-studied types of synchronic bias are complexity bias, a bias against formally complex patterns, and substantive bias, a bias against phonetically unnatural patterns. While most previous work has focused on…

This study examined how intervention dose frequency affects phonological acquisition and generalization in preschool children with speech sound disorders (SSD). Using a multiple-baseline, single-participants experimental design, eight English-speaking children with SSD (4;0 to 5;6) were split into two dose frequency conditions (4…

Purpose: This study compared perception of consonants in medial position by preschoolers, with and without speech sound disorder (SSD), with similar vocabulary and language skills. In addition, we investigated the association between speech perception and production skills. Method: Participants were 36 monolingual English-speaking children with…

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…