This dissertation explores the relationship between quantitative phonetic measurements and listener identification of accents of English, focusing on phonetic distance and its perceptual correlates across various English accent varieties. The Levenshtein distance (LD) measure, which quantifies string similarity by calculating the minimum cost of…

Understanding speech in an accent or dialect different than one's own can be challenging. McLaughlin and Van Engen (2020) were the first to quantify this increase in listening effort using Task Evoked Pupillary Response (TEPR), a common measure of cognitive arousal. They found that monolingual, English speaking adults' pupils dilated more quickly…

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…

Due in part to its complex nature, there is still much to uncover in the investigation of the neural processes that contribute to synchronization between speakers and listeners during communication in the context of social cognition, specifically between native and nonnative English speakers and listeners. This study used a novel method of…

The extant studies addressing second language phonetic perception assume that second language phonemes are perceived to be similar to first language phonemes, and tend to be substituted by learners of English as a foreign language. This study aimed to assess the perceptual relationship between the phonemes of English and the sound units of Omani…

People often experience difficulties when they first hear a novel accent. Prior research has shown that relatively fast natural accent accommodation can occur. However, there has been little investigation of the underlying perceptual mechanism that drives the learning. The current study examines whether phonemic boundary changes play a central…

During conversation, talkers may adapt their speech in a variety of ways. One form of speech adaptation is clear speech, in which a talker selectively hyperarticulates segments when faced with specific communication challenges. The present speech production experiment investigated how talkers adapt a common feature of American English dialects:…

Substantial individual differences exist in regard to type and amount of experience with variable speech resulting from foreign or regional accents. Whereas prior experience helps with processing familiar accents, research on how experience with accented speech affects processing of unfamiliar accents is inconclusive, ranging from perceptual…

All language use reflects the user's social identity in systematic ways. While humans can easily adapt to this sociolinguistic variation, automatic speech recognition (ASR) systems continue to struggle with it. This dissertation makes three main contributions. The first is to provide evidence that modern state-of-the-art commercial ASR systems…

This study investigates how second language (L2) listeners' perception is affected by two factors: the listeners' experience with the target dialect -- North American English (NAE) vs. Standard Southern British English (SSBE) -- and talkers' language background: native vs. non-native talkers; i.e. interlanguage speech intelligibility benefit…

This paper includes two interrelated studies. The first production study investigates the timing patterns of English as spoken by Chinese learners with different dialect backgrounds. The second comprehension study explores native and non-native speakers' assessments of the intelligibility of Chinese-accented English, and examines the effects of…

The current experiments examined how native Parisian French and native Swiss French listeners use vowel duration in perceiving the /[openo]/-/o/ contrast. In both Parisian and Swiss French /o/ is longer than /[openo]/, but the difference is relatively large in Swiss French and quite small in Parisian French. In Experiment 1 we found a parallel…

Listeners are faced with enormous variation in pronunciation, yet they rarely have difficulty understanding speech. Although much research has been devoted to figuring out how listeners deal with variability, virtually none (outside of sociolinguistics) has focused on the source of the variation itself. The current experiments explore whether…

Listeners can explicitly categorize unfamiliar talkers by regional dialect with above-chance performance under ideal listening conditions. However, the extent to which this important source of variation affects speech processing is largely unknown. In a series of four experiments, we examined the effects of dialect variation on speech…