Individuals differ in their ability to perceive and learn unfamiliar speech sounds, but we lack a comprehensive theoretical account that predicts individual differences in this skill. Predominant theories largely attribute difficulties of non-native speech perception to the relationships between non-native speech sounds/contrasts and…

Purpose: This study explores the role of overt and covert contrasts in speech perception by children with speech sound disorder (SSD). Method: Three groups of preschool-aged children (typically developing speech and language [TD], SSD with /s/~/?/ contrast [SSD-contrast], and SSD with /s/~/?/ collapse [SSD-collapse]) completed an identification…

Purpose: The purpose of this study was to determine if an objective measure of speech production could serve as a vocal biomarker for the effects of high-frequency hearing loss on speech perception. It was hypothesized that production of voiceless sibilants is governed sufficiently by auditory feedback that high-frequency hearing loss results in…

Purpose: Because reading is an audiovisual process, reading impairment may reflect an audiovisual processing deficit. The aim of the present study was to test the existence and scope of such a deficit in adult readers with dyslexia. Method: We tested 39 typical readers and 51 adult readers with dyslexia on their sensitivity to the simultaneity of…

Musical expertise and working memory (WM) have been isolated as being the most important predictors of phonetic aptitude -- meaning the ability to imitate unfamiliar speech material. Although the link between language functions and musical expertise has been subject to many investigations, specific languages and their individual link to musical…

Purpose: This study implemented a pretest-intervention-posttest design to examine whether multiple-talker identification training enhanced phonetic perception of the /ba/-/da/ and /wa/-/ja/ contrasts in adult listeners who were deafened postlingually and have cochlear implants (CIs). Method: Nine CI recipients completed 8 hours of identification…

In connected speech, phonological assimilation to neighboring words can lead to pronunciation variants (e.g., "garden bench" [arrow right] "garde'm' bench"). A large body of literature suggests that listeners use the phonetic context to reconstruct the intended word for assimilation types that often lead to incomplete assimilations (e.g., a…

Purpose: The purpose of this study was to determine listeners' ability to learn talker identity from speech produced with an electrolarynx, explore source and filter differentiation in talker identification, and describe acoustic-phonetic changes associated with electrolarynx use. Method: Healthy adult control listeners learned to identify…

Recent research has shown that speakers are sensitive to non-contrastive phonetic detail present in nonnative speech (e.g. Escudero et al. 2012; Wilson et al. 2014). Difficulties in interpreting and implementing unfamiliar phonetic variation can lead nonnative speakers to modify second language forms by vowel epenthesis and other changes. These…

How are languages learned, and to what extent are learning mechanisms similar in infant native-language (L1) and adult second-language (L2) acquisition? In terms of vocabulary acquisition, we know from the infant literature that the ability to discriminate similar-sounding words at a particular age does not guarantee successful word-meaning…

The present study is concerned with lax /[upsilon]/-fronting in Standard British English and in particular with whether this sound change in progress can be attributed to a waning of the perceptual compensation for the coarticulatory effects of context. Younger and older speakers produced various monosyllables in which /[upsilon]/ occurred in…

Both subjective impressions and previous research with monolingual listeners suggest that a foreign accent interferes with word recognition in infants, young children, and adults. However, because being exposed to multiple accents is likely to be an everyday occurrence in many societies, it is unexpected that such non-standard pronunciations would…

Current theoretical approaches differ in their assessment of the influences of biomechanical and perceptual factors on speech production. This dissertation investigates these influences on the relative timing of the two gestures typically involved in the production of American English laterals: tongue tip raising and tongue dorsum backing.…

This study explored the developmental trends and phonetic category formation in bilingual children and adults. Participants included 30 fluent Spanish-English bilingual children, aged 8-11, and bilingual adults, aged 18-40. All completed gating tasks that incorporated code-mixed Spanish-English stimuli. There were significant differences in…

Speech remains intelligible despite the elimination of canonical acoustic correlates of phonemes from the spectrum. A portion of this perceptual flexibility can be attributed to modulation sensitivity in the auditory-to-phonetic projection, although signal-independent properties of lexical neighborhoods also affect intelligibility in utterances…