This dissertation investigates how the abstract representation of vowels affects spoken word recognition in Brazilian Portuguese and American English by examining two issues in theoretical phonology and speech processing: underspecification theory, and underlying representation when there is alternation. Three experiments were conducted in…

Background: Accurate nonword repetition (NWR) is contingent on many underlying skills, including encoding, memory and motor planning and programming. Though vowel errors are frequently associated with childhood apraxia of speech (CAS), several recent studies have found that children with developmental language disorder (DLD) produce high rates of…

There is a long-standing debate in the literature about the benefits that acoustic components of Infant Directed Speech (IDS) might have for infants' language acquisition. One of the highly contested features is vowel space expansion, which refers to the enlargement of the acoustic space between the corner vowels /i, u, a/ in IDS compared to Adult…

Purpose: Despite known motor and spoken language impairments in autism spectrum disorder (ASD), the motor skills underlying speech production and their relationship with language skills have rarely been directly investigated in this population. Method: Thirty-nine autistic children (14 minimally verbal [MV], 25 verbal [V]) and 11 non-autistic…

Dialects vary in their allophonic patterns, which can affect listeners' phonological and lexical representations. I explore how different exposure to dialect-specific allophonic patterns for two vowels in American English, /ae ai/, affects listeners' lexical processing behaviors across three perception tasks: perceptual similarity, priming, and…

Korean learners of English are known to repair consonant clusters, which are not allowed in their native language, with an epenthetic vowel [close central unrounded vowel]. The purpose of the present study is to examine whether the perception-production link of such an illusory vowel in a second language (L2) is only within and not across…

During spoken word processing, native (L1) listeners use allophonic variation to predictively rule out word competitors and speed up word recognition. There is some evidence that second language (L2) learners develop an awareness of allophonic distributions in their L2, but whether they use their knowledge to facilitate word recognition online,…

This study presents a reanalysis of existing data to investigate whether a relationship between perception and production abilities regarding a challenging second-language (L2) phonological contrast is observable (a) when both modalities must rely on accessing stored lexical representations and (b) when there is an asymmetry in task focus between…