<div>Voice Onset Time (VOT) and onset f0 are known correlates of voicing distinctions in stops and both contribute to the production and perception of voicing (House & Fairbanks, 1953; Abramson & Lisker, 1965; Ohde, 1984). As the values of VOT and onset f0, which correspond to voicing categories, vary cross-linguistically, a second language (L2) learner has to acquire a novel use of these acoustic cues to produce and perceive voicing in their L2. Although the acquisition of the primary voicing cue, VOT, has been studied extensively in L2 research (Flege & Eefting, 1988; Flege 1991; Birdsong et al. 2007), little is known about the acquisition of onset f0. The present study compares the use of VOT and onset f0 in French and English speech produced by American learners of French (23). The study also examines evidence for phonetic drift in L2 learners by comparing their English productions to a monolingual control group (33). Results indicate that although learners’ VOT values in French were heavily influenced by English, their onset f0 production in both English and French were on target, showing that learners are able to manipulate the two cues independently of one another. Little evidence of the effect of learners’ second language on the first language was found.</div><div>This study also examines the role of individual learning history on the realization of VOT and onset f0, determining that average number of hours speaking French and age of L2 acquisition (AOA) reported by learners shows the strongest correlation with the learner’s acoustic productions.</div>

<p>Voice onset time (VOT) är en akustisk tidsparameter som speglar den talmotoriska kontrollen. VOT anses vara det mest tillförlitliga akustiska tecknet på om en klusil är tonande eller tonlös.</p><p>Syfte: att undersöka och jämföra VOT hos barn i åldrarna 3, 4 och 5 år samt jämföra med tidigare publicerade svenska vuxenvärden.</p><p>Metod: 83 barn (51 flickor; 32 pojkar) ljudinspelades vid produktion av minimala par för de svenska klusilerna.</p><p>Resultat: medelvärden för VOT minskade genomgående med åldern. Signifikanta skillnader erhölls mellan 3- och 5-åringarna för ljuden /t k b g/ samt gällande användandet av förton för tonande klusiler. Jämförelser med vuxenvärden visade att vuxna i högre utsträckning hade förton för de tonande ljuden och kortare VOT för de tonlösa ljuden än de, i föreliggande studie, deltagande barnen. Inga signifikanta könsskillnader påträffades.</p><p>Resultaten av föreliggande studie kan användas som referensmaterial vid bedömning av barn med talmotoriska störningar.<em></em></p>

Voice onset time (VOT) är en akustisk tidsparameter som speglar den talmotoriska kontrollen. VOT anses vara det mest tillförlitliga akustiska tecknet på om en klusil är tonande eller tonlös. Syfte: att undersöka och jämföra VOT hos barn i åldrarna 3, 4 och 5 år samt jämföra med tidigare publicerade svenska vuxenvärden. Metod: 83 barn (51 flickor; 32 pojkar) ljudinspelades vid produktion av minimala par för de svenska klusilerna. Resultat: medelvärden för VOT minskade genomgående med åldern. Signifikanta skillnader erhölls mellan 3- och 5-åringarna för ljuden /t k b g/ samt gällande användandet av förton för tonande klusiler. Jämförelser med vuxenvärden visade att vuxna i högre utsträckning hade förton för de tonande ljuden och kortare VOT för de tonlösa ljuden än de, i föreliggande studie, deltagande barnen. Inga signifikanta könsskillnader påträffades. Resultaten av föreliggande studie kan användas som referensmaterial vid bedömning av barn med talmotoriska störningar.

abstract: ABSTRACT The absence of the consonant sound /p/ in Libyan Arabic leads Libyan speakers of English to pronounce /p/ as /b/. This study examines how Libyan Arabic speakers distinguish the English /p/ and /b/ in their production of L2 English. The study also examines the effect of the production contexts and the learning environment on two groups of Libyan Arabic speakers' attainment of the English /p/ in the USA and Libya. The study collected voice recordings of word-initial /p/ and /b/ in isolated-words, minimal pairs, and sentences in English from both Libyan Arabic speakers and American English speakers. The study also collected Libyan Arabic stop consonants /b/, /t/, /d/, /k/, and /g/ from the Libyan participants. The voice recording data were collected using the WhatsApp mobile application from all participants and the Libyan Arabic participants were also asked to fill an online survey. Using voice onset time (VOT) as a measurement tool, this study measured the English and Libyan Arabic data through Praat software. The findings show that most Libyan Arabic participants distinguish between /p/ and /b/, but they did not have as high VOT averages as the American participants' /p/. It also reveals that the production context, especially in minimal pairs and sentence contexts, has an effect on their participants' production. However, the learning environment does not have an effect on the Libyan participants' pronunciation of /p/ in this study. / Dissertation/Thesis / Masters Thesis English 2014

The present investigation analyzed early second language (L2) learning in adults. A common finding regarding L2 acquisition is that early learning appears to be necessary in order to perform on the same level as a native speaker. Surprisingly, many current theoretical models posit that the human ability to learn novel speech sounds remains active throughout the lifespan. In light of this fact, this project examines L2 acquisition in late learners with a special focus on L1/L2 use, input, and context of learning. Research regarding L1/L2 use has tended to be observational, and throughout the previous six decades of L2 research the role of input has been minimized and left largely unexplained. This study includes two production experiments and two perception experiments and focuses on the role of L1/L2 use and input in L2 acquisition in late learners in order to add to current research regarding their role in accurately and efficiently acquiring a novel speech sound. Moreover, this research is concerned with shedding light on when, if at all, during the acquisition process late learners begin to acquire a new, language-specific phonetic system, and the amount of exposure necessary in order to acquire L2 fine-phonetic detail. The experimental design presented in the present study also aims to shed light on the temporal relationship between production and perception with regard to category formation. To begin to fully understand these issues, the present study proposes a battery of tasks which were administered throughout the course of a domestic immersion program. Domestic immersion provides an understudied linguistic context in which L1 use is minimized, target language use is maximized, and L2 input is abundant. The results suggest that L2 phonetic category formation occurs at an early stage of development, and is perceptually driven. Moreover, early L2 representations are fragile, and especially susceptible to cross-language interference. Together, the studies undertaken for this work add to our understanding of the initial stages of the acquisition of L2 phonology in adult learners.

Speech development in autism spectrum disorder (ASD) has rarely been studied, yet residual speech sound errors are over 30 times more common in children with ASD than in the general population. Two main theories could explain this. The Social Feedback Loop proposes that toddlers with ASD vocalize less often and so have fewer opportunities to benefit from adult feedback. Thus, fewer vocalizations and perceptible differences in those vocalizations should be found in toddlers with ASD. The Speech Attunement Framework proposes that while toddlers with ASD “tune in” to their native languages well enough to acquire language normally, they lack the ability to “tune up” their articulation to the same level of precision as typically-developing children. Thus, differences in the vocalizations of toddlers with ASD may be perceptible or not, and should exist irrespective of differences in vocalization rate. This study longitudinally examines vocalization rate, consonant inventory size, and voice-onset time (VOT) in syllable-initial bilabial stops using 30-minute speech samples from toddlers in three groups: those at low risk for ASD (LRC), those at high risk for ASD with ASD themselves (HRA+), and those at high risk for ASD without ASD (HRA ) . Transient delays in consonant development were found in both HRA- and HRA+, but only HRA+ toddlers vocalized less often. Further, the relationship between vocalization rate and consonant inventory was significantly different from LRC only for HRA-. VOT development was similar across groups, except that fewer HRA+ 36-month-olds produced distinct /b/ and /p/ populations, as measured by t-test and by Cohen’s d ≥ 0.8 between mean VOTs in the two populations of stops. Results support the Speech Attunement Framework. Consonant acquisition delays are not related to differences in vocalization rate and are not found only in toddlers who develop ASD. The finding of sub-perceptual acoustic differences in stop production in toddlers who develop ASD, with no accompanying differences in production rate, also supports the Speech Attunement Framework. This suggests that the Social Feedback Loop is not diminished in ASD by lower vocalization rate, but that toddlers with ASD may have diminished ability to monitor their own speech.

Purpose: This study examined voice onset time (VOT) in children with and without vocal fold nodules (VFN). The purpose of this study was to provide further evidence regarding the need for individualized research and treatment dedicated to the pediatric population. The pediatric population has a distinctly different laryngeal mechanism than adults, as they are still developing. Although the pediatric system is anatomically different from that of a fully mature adult system, treatment for children with VFN is largely based on adult research. This study examined the VOTs of voiceless consonants, as the transition from the voiceless consonant to the subsequent vowel requires significant vocal and articulatory control and coordination. Measures of VOT change throughout the maturation as VOT follows a significant developmental pattern. Children with and without VFN were enlisted in order to examine the effects VFN have on VOT. Hypotheses: We hypothesize that children with VFN would have differences in 1) average VOT values compared to the control group, with no prediction for direction of difference (shorter and longer), and 2) between-word variability of VOT values compared to the control group, with no prediction for direction of difference (more variable and less variable). Methods: Participant data were retrospectively collected and included children between 6 and 12 years old with VFN and age- and sex-matched controls. Participants were recorded producing the six CAPE-V sentences. Four voiceless consonants were selected for VOT analysis. Praat was utilized to manually mark the vocal onset of the stop consonant by the current researcher. A previous researcher identified the vocal offset, and each placement was confirmed by the current researcher. VOT was calculated as the time between the stop consonant burst and the vocal onset of the vowel. Results: There was no significant difference between the VFN and the control groups in average VOT or VOT variability. Within the VFN group, participants who were more dysphonic (lower cepstral peak prominence (CPP) values) had more variable VOT values. Participants in the VFN group had lower CPP values than the control group, suggesting that CPP measures are a reliable indicator of dysphonia. Additionally, within the VFN group, male children had lower CPP values than female children. Conclusion: Although no group difference was found, the within-group analyses indicated that VFNs impacted productions. Children with VFN who were more dysphonic had increased VOT variability. This may suggest that VFN impact a child’s ability to phonate therefore causing more variability within productions. Future research is needed to study the impact dysphonia treatment for children with VFN may have on VOT values. Additionally, a longitudinal study of the impact of VFNs on VOT values during developmental stages may be warranted. / Public Health

This study examined the Voice onset time (VOT) of Mandarin and English initial position stops as produced by native American-English speaking learners of Mandarin and also native speakers. The study primarily investigated the role of second language experience on native-like production of L2 VOT for the Mandarin stops /p, t, k, ph, th, kh/ and additionally examined any evidence for phonetic drift in the L1 English VOT as a result of L2 Mandarin learning and acquisition. To achieve this, the production of L2 Mandarin and L1 English by native AmericanEnglish speaking learners of Mandarin of two different levels of experience (beginner and advanced learners) were compared to that of monolingual Native speakers of Mandarin andEnglish. In total, thirty native American-English speaking learners of Mandarin, eight monolingual native Mandarin speakers, and eight monolingual American-English speakers participated in the study. Data was elicited via participants reading aloud prepared lists of Mandarin and/or English words. Statistical testing indicates that as a group beginner learners produced significantly different mean VOT than native Mandarin speakers for all six stops. In contrast, the advanced learner group's mean VOT only significantly differed with native speakers for /t/, indicating native-like VOT for the remaining five stops. Individual analysis of VOT data for L2 Mandarin long-lag stops /ph, th, kh/ showed that advanced (7 of 15) and even some beginner (3 of 15) participants were capable of producing native-like VOT for the whole set of long-lag stops and also that a number of participants were able to produce native-like VOT for some but not all of the long-lag stops. Logistic regression analysis examining the effect and influence of L2 experience and demographic related variables indicates only gender and Mandarin-speaking church missionary service to have a significant effect on native-like VOT probability with females and returned missionaries significantly more likely to achieve native-like VOT. Analysis of learner participants' L1 English VOT showed that for all three of the English long-lag stops (/p, t, k/), advanced learners of Mandarin produced significantly longer VOT than monolingual English speakers, indicating L1 phonetic drift in the form of assimilation towards the longer length of Mandarin long-lag stops. Significant difference was only found between beginner learner English VOT and monolingual VOT for /p/, suggesting instances of significant L1 drift increase when more L2 experience has been gained.

Infants 6-8 months old are able to identify nearly every speech sound contrast on which they have been tested, regardless of whether that contrast represents an across-category (two different phonemes) phonetic change in their native language or not. A child's ability to identify non-native consonant contrasts greatly diminishes by 11-12 months of age. The present study examined speech sound discrimination in three groups of listeners. Adult second language (L2) listeners of Spanish were compared with native English listeners with no knowledge of Spanish and native Mexican listeners to determine if they would show the ability to discriminate phonetic distinctions that are present in Spanish and not English. Behavioral and Electrophysiological measures were obtained in response to a continuum of bilabial consonant-vowel (CV) stimuli that differed in voice onset time (VOT) from -50 to 30 ms VOT (/ba/ to /pa/). The -50 ms VOT stimulus was paired with each of the others to form stimulus pairs with varying degrees of acoustic difference. Behavioral data showed that L2 listeners of Spanish perceived a transition from /ba/ to /pa/ later than native Spanish listeners but earlier than English only listeners. Electrophysiological data using the mismatch negativity revealed that the both L2 Spanish and native Spanish listeners perceived a distinction between stimuli in the stimulus pairs 20 ms earlier than English only listeners. These results support the theory that underlying neural-sensory representations of speech may be altered by linguistic experiences, and that the loss of non-native speech sound discrimination abilities in infancy and the regaining of these abilities in adulthood is not due merely to attentional bias.

The purpose of this study is to determine whether children with autism recognize the same perceptual voicing boundaries of stop consonants as normally developing children of the same age group. This was explored using three groups of participants: ten children with autism between the ages of 8-14, five typically developing children between the ages of 8-14, and five typically developing seven-year-old children. Children in all groups listened to initial stop consonant syllables with voicing contrasts, with voiced and voiceless cognates presented. The initial consonants were altered along a voice onset time continuum within the typically perceived boundaries of each consonant. Participants were instructed to select the box containing the letter of the initial consonant they perceive when they hear each syllable. Results revealed greater difference between the responses of the children with autism when compared with the older control group, than when compared with the younger children. The responses of the children with autism were more similar to those of the children in the second control group. This could be indicative of a delay in the children with autism of perception of the categorical boundaries along the dimension of voice onset time compared to typical children's perception of these consonants.