The vowel systems of Quichua-Spanish bilinguals. Age of acquisition effects on the mutual influence of the first and second languages

Language Contact Within the Speaker: Phonetic Variation and Crosslinguistic Influence

A recent model of sound change posits that the direction of change is determined, at least in part, by the distribution of variation within speech communities. We explore this model in the context of bilingual speech, asking whether the less variable language constrains phonetic variation in the more variable language, using a corpus of spontaneous speech from early Cantonese-English bilinguals. As predicted, given the phonetic distributions of stop obstruents in Cantonese compared with English, intervocalic English /b d g/ were produced with less voicing for Cantonese-English bilinguals and word-final English /t k/ were more likely to be unreleased compared with spontaneous speech from two monolingual English control corpora. Whereas voicing initial obstruents can be gradient in Cantonese, the release of final obstruents is prohibited. Neither Cantonese-English bilingual initial voicing nor word-final stop release patterns were significantly impacted by language mode. These results provide evidence that the phonetic variation in crosslinguistically linked categories in bilingual speech is shaped by the distribution of phonetic variation within each language, thus suggesting a mechanistic account for why some segments are more susceptible to cross-language influence than others.

Learning and change in a dual lexicon model of speech production

Speech motor processes and phonological forms influence one another because speech and language are acquired and used together. This hypothesis underpins the Computational Core (CC) model, which provides a framework for understanding the limitations of perceptually-driven changes to production. The model assumes a lexicon of motor and perceptual wordforms linked to concepts and whole-word production based on these forms. Motor wordforms are built up with speech practice. Perceptual wordforms encode ambient language patterns in detail. Speech production is the integration of the two forms. Integration results in an output trajectory through perceptual-motor space that guides articulation. Assuming successful communication of the intended concept, the output trajectory is incorporated into the existing motor wordform for that concept. Novel word production exploits existing motor wordforms to define a perceptually-acceptable path through motor space that is further modified by the perceptual wordform during integration. Simulation results show that, by preserving a distinction between motor and perceptual wordforms in the lexicon, the CC model can account for practice-based changes in the production of known words and for the effect of expressive vocabulary size on production accuracy of novel words.

Phonetic Development of an L2 Vowel System and Tandem Drift in the L1: A Residence Abroad and L1 Re-Immersion Study

This study analyzes the production of native (L1) and foreign (L2) vowels by 42 L1 English learners of French (ELoF) at the start and end of a 6-month residence abroad (RA) in a French-speaking country. Data are also reported from a delayed post-test, which takes place 10 months after a subsection of participants (n = 27) return to the L1 English environment. Results reveal systemic phonetic drift in ELoF's L1 English vowels over the RA, and this accompanies the phonetic development occurring in the participants' L2 French vowel system, a phenomenon we label "tandem drift." This L1-L2 link is also supported by interspeaker variation: the individuals whose L2 French vowels shift the most are also the participants who exhibit the most substantial L1 phonetic drift in the same direction. Results for the L1 re-immersion time point suggest a partial-but not complete-reversal of phonetic drift, whereas no reversal of the L2 gains made over the RA is apparent. Nevertheless, at the individual level, the learners whose L2 gains reverse the most upon L1 re-immersion are also most likely to exhibit reverse phonetic drift in their L1. Overall, these findings indicate a relationship between L2 speech learning and L1 phonetic drift, which we argue is driven by the global phonetic properties of both L2 and L1 becoming linked at a representational level. Although these representations appear malleable, it is clear that recent changes are not guaranteed to reverse despite substantial re-exposure to L1 input. Implications for the distinction between drift and attrition are discussed.

The influence of inter-dialect contact on the Korean three-way laryngeal distinction: An acoustic comparison among Seoul Korean speakers and Gyeongsang speakers with limited and extended residence in Seoul

This exploratory study investigates the acoustic correlates of the Korean three-way laryngeal stop distinction in Gyeongsang long-term (LT) transplants who were born in the Gyeongsang region but moved to Seoul to pursue higher education. Acoustic data were collected from eight LT transplants, five short-term (ST) transplants, and 11 Seoul speakers to examine whether exposure to Seoul Korean (SK) affects Gyeongsang speakers' cue-weighting in distinguishing stops in production. LT transplants produced stimuli in both Gyeongsang and Seoul dialects. A cue-weighting model based on the acoustic data reveals that voice onset time (VOT) is less important to distinguish lenis from aspirated stops for Seoul speakers and for LT transplants' SK, as compared to ST transplants and LT transplants' Gyeongsang Korean (GK). In addition, fundamental frequency (F0) is more important for the lenis-aspirated distinction for Seoul speakers and LT transplants' SK, as compared to ST and LT transplants' GK, showing that LT transplants rely less on VOT and more on F0 to distinguish lenis from aspirated stops compared to ST transplants. LT transplants' SK reveals that they rely more on VOT and less on F0 compared to SK speakers. The cue-weighting model of the LT transplants provide empirical evidence that a series of sound changes in GK is due to inter-dialect contact.

LANGUAGE EXPOSURE PREDICTS CHILDREN'S PHONETIC PATTERNING: EVIDENCE FROM LANGUAGE SHIFT

Although understanding the role of the environment is central to language acquisition theory, rarely has this been studied for children's phonetic development, and receptive and expressive language experiences in the environment are not distinguished. This last distinction may be crucial for child speech production in particular, because production requires coordination of low-level speech-motor planning with high-level linguistic knowledge. In this study, the role of the environment is evaluated in a novel way-by studying phonetic development in a bilingual community undergoing rapid language shift. This sociolinguistic context provides a naturalistic gradient of the amount of children's exposure to two languages and the ratio of expressive to receptive experiences. A large-scale child language corpus encompassing over 500 hours of naturalistic South Bolivian Quechua and Spanish speech was efficiently annotated for children's and their caregivers' bilingual language use. These estimates were correlated with children's patterns in a series of speech production tasks. The role of the environment varied by outcome: children's expressive language experience best predicted their performance on a coarticulation-morphology measure, while their receptive experience predicted performance on a lower-level measure of vowel variability. Overall these bilingual exposure effects suggest a pathway for children's role in language change whereby language shift can result in different learning outcomes within a single speech community. Appropriate ways to model language exposure in development are discussed.

Do a Learner’s Background Languages Change with Increasing Exposure to L3? Comparing the Multilingual Phonological Development of Adolescents and Adults

The present study longitudinally explores regressive phonological cross-linguistic influence (CLI) in seven adolescents (aged 12–13) and seven adults (aged 21–39) by examining voice-onset time (VOT) of /p,t,k/ in their first, second, and third language (L1, L2, and L3, respectively). All participants had the same language combination (L1 German, L2 English, L3 Polish) and were recorded completing a range of production tasks in all three languages four times over the course of the first year of L3 learning. The scope of previous research on phonological CLI is thus broadened in two ways: (1) by tracing the development of all languages upon the arrival of a new language in a multilingual’s system longitudinally, and (2) by investigating CLI patterns in two age groups when input and learning environment are comparable. Previous L2 age studies have mostly only made retrospective assumptions about (target) language development, so that longitudinal data, including the entire language repertoire of multilingual speakers, are needed to substantiate claims made in that regard. For the adolescent group, significant changes to both their L1 and L2 over time were found, while the adults’ background languages remained relatively stable on the group level. However, for both groups, much individual variation was uncovered.

Perceptual Categorization of Hñäñho-Specific Vowel Contrasts by Hñäñho Heritage Speakers in Mexico

For a large proportion of Mexican Indigenous speakers, it is common for the use of their native languages to shift across generations towards Spanish, the majority language in Mexico. This specific population can be defined as heritage speakers (HS) of their indigenous language, since many of them are Spanish-dominant bilinguals with a strong connection to their minority native language and culture, both of which they might only maintain in their family home where they were raised. The present study investigates the perceptual sensitivity of HS of Santiago Mexquititlán Otomi (Hñäñho) towards sounds of their native language to examine if these HS can accurately categorize Hñäñho vowels or whether their categorization is influenced by their dominant Spanish vowel system. Twelve Hñäñho HS (HHS) and twelve Mexican Spanish monolinguals (MSM) listened to the Hñäñho-specific vowel contrasts /a – ɔ/ and /ɔ – o/ and categorized them among the vowels of their respective mother tongue. Our results indicate that HHS correctly categorize vowels /a/ and /o/, which exist in both Hñäñho and Spanish, but do not accurately categorize the Hñäñho-specific vowel /ɔ/. Moreover, HHS and MSM showed similar patterns in terms of the proportion of /ɔ/ categorized as either /a/ and /o/. These results have implications for the maintenance of language-specific vowel contrasts and the vowel system of a minority language, such as Hñäñho, in the context of language shift towards Spanish in Mexico.

Crosslinguistic Influence in the Discrimination of Korean Stop Contrast by Heritage Speakers and Second Language Learners

The present study examines the extent of crosslinguistic influence from English as a dominant language in the perception of the Korean lenis–aspirated contrast among Korean heritage speakers in the United States (N = 20) and English-speaking learners of Korean as a second language (N = 20), as compared to native speakers of Korean immersed in the first language environment (N = 20), by using an AX discrimination task. In addition, we sought to determine whether significant dependencies could be observed between participants’ linguistic background and experiences and their perceptual accuracy in the discrimination task. Results of a mixed-effects logistic regression model demonstrated that heritage speakers outperformed second language learners with 85% vs. 63% accurate discrimination, while no significant difference was detected between heritage speakers and first language-immersed native speakers (85% vs. 88% correct). Furthermore, higher verbal fluency was significantly predictive of greater perceptual accuracy for the heritage speakers. The results are compatible with the interpretation that the influence of English on the discrimination of the Korean laryngeal contrast was stronger for second language learners of Korean than for heritage speakers, while heritage speakers were not apparently affected by dominance in English in their discrimination of Korean lenis and aspirated stops.

Vowel development in young Mandarin-English bilingual children

This study examined the development of vowel categories in young Mandarin -English bilingual children. The participants included 35 children aged between 3 and 4 years old (15 Mandarin-English bilinguals, six English monolinguals, and 14 Mandarin monolinguals). The bilingual children were divided into two groups: one group had a shorter duration (<1 year) of intensive immersion in English (Bi-low group) and one group had a longer duration (>1 year) of intensive immersion in English (Bi-high group). The participants were recorded producing one list of Mandarin words containing the vowels /a, i, u, y, ɤ/ and/or one list of English words containing the vowels /i, ɪ, e, ɛ, æ, u, ʊ, o, ɑ, ʌ/. Formant frequency values were extracted at five equidistant time locations (the 20-35-50-65-80% point) over the course of vowel duration. Cross-language and within-language comparisons were conducted on the midpoint formant values and formant trajectories. The results showed that children in the Bi-low group produced their English vowels into clusters and showed positional deviations from the monolingual targets. However, they maintained the phonetic features of their native vowel sounds well and mainly used an assimilatory process to organize the vowel systems. Children in the Bi-high group separated their English vowels well. They used both assimilatory and dissimilatory processes to construct and refine the two vowel systems. These bilingual children approximated monolingual English children to a better extent than the children in the Bi-low group. However, when compared to the monolingual peers, they demonstrated observable deviations in both L1 and L2.

Between Äh(m) and Euh(m): The Distribution and Realization of Filled Pauses in the Speech of German-French Simultaneous Bilinguals

Filled pauses are well known for their speaker specificity, yet cross-linguistic research has also shown language-specific trends in their distribution and phonetic quality. To examine the extent to which speakers acquire filled pauses as language- or speaker-specific phenomena, this study investigates the use of filled pauses in the context of adult simultaneous bilinguals. Making use of both distributional and acoustic data, this study analyzed UH, consisting of only a vowel component, and UM, with a vowel followed by [m], in the speech of 15 female speakers who were simultaneously bilingual in French and German. Speakers were found to use UM more frequently in German than in French, but only German-dominant speakers had a preference for UM in German. Formant and durational analyses showed that while speakers maintained distinct vowel qualities in their filled pauses in different languages, filled pauses in their weaker language exhibited a shift towards those in their dominant language. These results suggest that, despite high levels of variability between speakers, there is a significant role for language in the acquisition of filled pauses in simultaneous bilingual speakers, which is further shaped by the linguistic environment they grow up in.

Exposure to a second language in infancy alters speech production

We evaluated the impact of exposure to a second language on infants' emerging speech production skills. We compared speech produced by three groups of 12-month-old infants while they interacted with interlocutors who spoke to them in Spanish and English: monolingual English-learning infants who had previously received 5 hours of exposure to a second language (Spanish), English- and Spanish-learning simultaneous bilinguals, and monolingual English-learning infants without any exposure to Spanish. Our results showed that the monolingual English-learning infants with short-term exposure to Spanish and the bilingual infants, but not the monolingual English-learning infants without exposure to Spanish, flexibly matched the prosody of their babbling to that of a Spanish- or English-speaking interlocutor. Our findings demonstrate the nature and extent of benefits for language learning from early exposure to two languages. We discuss the implications of these findings for language organization in infants learning two languages.

The Effect of Instructed Second Language Learning on the Acoustic Properties of First Language Speech

This paper reports on a comprehensive phonetic study of American classroom learners of Russian, investigating the influence of the second language (L2) on the first language (L1). Russian and English productions of 20 learners were compared to 18 English monolingual controls focusing on the acoustics of word-initial and word-final voicing. The results demonstrate that learners’ Russian was acoustically different from their English, with shorter voice onset times (VOTs) in [−voice] stops, longer prevoicing in [+voice] stops, more [−voice] stops with short lag VOTs and more [+voice] stops with prevoicing, indicating a degree of successful L2 pronunciation learning. Crucially, learners also demonstrated an L1 phonetic change compared to monolingual English speakers. Specifically, the VOT of learners’ initial English voiceless stops was shortened, indicating assimilation with Russian, while the frequency of prevoicing in learners’ English was decreased, indicating dissimilation with Russian. Word-final, the duration of preceding vowels, stop closures, frication, and voicing during consonantal constriction all demonstrated drift towards Russian norms of word-final voicing neutralization. The study confirms that L2-driven phonetic changes in L1 are possible even in L1-immersed classroom language learners, challenging the role of reduced L1 use and highlighting the plasticity of the L1 phonetic system.

The Effects of Home Language and Bilingualism on the Realization of Lexical Stress in Welsh and Welsh English

This study investigates effects of long-term language contact and individual linguistic experience on the realization of lexical stress correlates in Welsh and Welsh English. To this end, a production study was carried out in which participants were asked to read out Welsh and English disyllabic words with stress on the penultimate syllable, placed within carrier phrases. Recordings were made of the productions of Welsh and English target words, by two groups of Welsh-English bilinguals differing in home language, as well as the productions of English target words by Welsh English monolinguals and speakers of Southern Standard British English (SSBE). Acoustic measures were taken of fundamental frequency (f0) and intensity ratios of stressed and unstressed vowels, duration of stressed and unstressed vowels, and duration of the post-stress consonant. The results of acoustic comparisons of Welsh English with SSBE and Welsh revealed that SSBE differs from the other groups in all measures of lexical stress. Welsh and Welsh English, however, show considerable phonetic overlap, albeit with language-specific differences in two of the five measures (unstressed vowel duration, intensity ratio). These findings suggest cross-language convergence in the realization of lexical stress in Welsh and Welsh English disyllabic words with penultimate stress. Individual linguistic experience, in turn, did not play a major role in the realization of lexical stress in these words. Bilinguals did not differ from monolinguals when speaking English, and home language also had no effect on any measure. This suggests that other factors must be responsible for the observed patterns. We discuss the possibility that the varieties of Welsh and Welsh English spoken in this community function as a sign of regional or peer group identity, rather than as markers of linguistic experience.

Arabic-Spanish Language Contact in Puerto Rico: A Case of Glottal Stop Epenthesis

The current study examines the realization of adjacent vowels across word boundaries in Arabic-Spanish bilinguals and Spanish monolinguals in Puerto Rico, focusing specifically on the rate of glottal stop epenthesis in this context (e.g., hombre africano to [ˈom.bre.ʔa.fri.ˈka.no]). It was hypothesized that Arabic-Spanish bilinguals would show a higher rate of glottal stop epenthesis than Spanish monolinguals because of transfer from Arabic. In addition, we investigated the possible effects of stress, vowel height, language dominance and bilingual type on the rate of glottal stop epenthesis. Results from a reading task with 8 participants showed no significant difference in glottalization between bilinguals and monolinguals. For monolinguals, glottalization was significantly more likely when the first vowel was low or stressed; significant interactions between vowel height and stress were found for the bilingual group. Language dominance was a significant factor, with Arabic-dominant bilinguals glottalizing more than the Spanish-dominant bilinguals. In addition, early sequential bilinguals favored glottalization slightly more than simultaneous bilinguals, without reaching significance. Our data suggests some effects of syllable structure transfer from Arabic, particularly in Arabic-dominant participants. To our knowledge, our study is the first exploration of Arabic and Spanish in contact in Puerto Rico, and the first to acoustically examine the speech of Arabic-Spanish bilinguals.

Analysis of Second Language Acquisition (SLA) Speech Perception Model & the Perception of Second Language Prosody

This paper provides a critical review on the major models of speech perception in second language (L2) acquisition. It is argued that some new models, such as L2LP and ASP, have more explanatory power for L2 speech perception. However, due to the different theoretical frameworks, objectives and hypotheses in these models, it is difficult to integrate these models into one which is universally applicable. Although most of these models were proposed for accounting for the perception of L2 segments, they can also be applied in the perception of L2 prosody. When these models are used in examining L2 speech prosody, the prosodic systems of both L1 and L2 should be thoroughly investigated first.

Bilingual phonological acquisition: the influence of language-internal, language-external, and lexical factors

This study examines the influence of language-internal (frequency and complexity of linguistic properties), language-external (percent French input, socioeconomic status (SES), and gender), and lexical factors (size of total and French vocabulary) on the phonological production abilities of monolingual and bilingual French-speaking children, aged 2;6. Children participated in an object and picture naming task in which they produced words selected to test different phonological properties. The bilinguals' first languages were coded in terms of the frequency and complexity of these phonological properties. Results indicated that bilinguals who spoke languages characterized by high frequency/complexity of codas and clusters had superior results in their coda and cluster accuracy in comparison to monolinguals. Bilinguals also had better coda and cluster accuracy scores than monolinguals. These findings provide evidence for cross-linguistic interaction in combination with a 'general bilingual effect'. In addition, percent French exposure, SES, total vocabulary, and gender influenced phonological production.

Effects of Exposure and Vowel Space Distribution on Phonetic Drift: Evidence from American English Learners of French

Recent work by Chang has shown that even at the very earliest stages of second language (L2) acquisition, the phonetic implementation of speakers' native English phoneme categories is slightly modified by contact with L2 Korean, which is referred to as "phonetic drift." This study investigates whether rapid phonetic drift generalizes to another pairing of languages. We examined naïve American English learners of French, who were recorded producing both American English and French vowels after one and six weeks of a study abroad program in Paris. In addition, the Study Abroad group is compared with proficient American English L1 speakers of French who have been residents of Paris for at least five years, to investigate the impact of long-term use of an L2 on the vowel categories of L1. Whereas the Study Abroad group showed no evidence of phonetic drift after six weeks, the Paris Residents' American English vowel space shifted along F1 and several English vowels demonstrated clear movement toward French monolingual norms. A closer look at the high vowels provides insight into how phonetic categories are influenced both by drift and by a pressure to keep vowel categories distinct between the languages. The results are also discussed with respect to potential effects of the size of the vowel inventory and the amount of input required to cause phonetic drift.

Non-Selective Lexical Access in Late Arabic-English Bilinguals: Evidence from Gating

Previous research suggests that late bilinguals who speak typologically distant languages are the least likely to show evidence of non-selective lexical access processes. This study puts this claim to test by using the gating task to determine whether words beginning with speech sounds that are phonetically similar in Arabic and English (e.g., [b,d,m,n]) give rise to selective or non-selective lexical access processes in late Arabic-English bilinguals. The results show that an acoustic-phonetic input (e.g., [bæ]) that is consistent with words in Arabic (e.g., [bædrun] "moon") and English (e.g., [bæd] "bad") activates lexical representations in both languages of the bilingual. This non-selective activation holds equally well for mixed lists with words from both Arabic and English and blocked lists consisting only of Arabic or English words. These results suggest that non-selective lexical access processes are the default mechanism even in late bilinguals of typologically distant languages.

Development of Spanish rhotics in Spanish-English bilingual children in the United States

Rhotics, particularly the trill, are late acquired sounds in Spanish. Reports of Spanish-English bilingual preschoolers document age-appropriate articulations, but studies do not explore productions once exposure to English increases. This paper reports on the rhotic productions of a cross-sectional sample of 31 Spanish-English bilingual children, ages 6;8 to 13;5. Children produced taps with high rates of accuracy across age groups; the trill did not reach 80% target production until age 11;3, later than reported for monolingual speakers. Increased English exposure is explored as a contributing factor, arguing a need for continued study of bilingual phonological development beyond the preschool years.

The emergence of phonetic categories in Korean-English bilingual children

The present study examined the speech production of three-year-old Korean-English bilingual (KEB) children. English and Korean stops, as well as front vowels in both languages, were compared acoustically among the KEB children, then also measured against those of their age-equivalent monolingual counterparts. Evidence of distinctive phonetic categorization in bilingual children was more salient in vowels than in stops. Vowels and stops produced by the bilingual children were not significantly different from those of their monolingual counterparts. The findings suggest that, similar to other language domains, two linguistic systems are apparent in the phonetic production component of three-year-old KEB children, but that phonetic distinctiveness in production may not emerge holistically in an across-the-board fashion, appearing earlier in vowels than stops. Thus, the phonetic production systems of the two languages may develop with only limited interaction in simultaneous KEB children exposed to two languages at an early age.

Cross-linguistic vowel variation in trilingual speakers of Saterland Frisian, Low German, and High German

The present study compares the acoustic realization of Saterland Frisian, Low German, and High German vowels by trilingual speakers in the Saterland. The Saterland is a rural municipality in northwestern Germany. It offers the unique opportunity to study trilingualism with languages that differ both by their vowel inventories and by external factors, such as their social status and the autonomy of their speech communities. The objective of the study was to examine whether the trilingual speakers differ in their acoustic realizations of vowel categories shared by the three languages and whether those differences can be interpreted as effects of either the differences in the vowel systems or of external factors. Monophthongs produced in a /hVt/ frame revealed that High German vowels show the most divergent realizations in terms of vowel duration and formant frequencies, whereas Saterland Frisian and Low German vowels show small differences. These findings suggest that vowels of different languages are likely to share the same phonological space when the speech communities largely overlap, as is the case with Saterland Frisian and Low German, but may resist convergence if at least one language is shared with a larger, monolingual speech community, as is the case with High German.

Language-independent talker-specificity in first-language and second-language speech production by bilingual talkers: L1 speaking rate predicts L2 speaking rate

Second-language (L2) speech is consistently slower than first-language (L1) speech, and L1 speaking rate varies within- and across-talkers depending on many individual, situational, linguistic, and sociolinguistic factors. It is asked whether speaking rate is also determined by a language-independent talker-specific trait such that, across a group of bilinguals, L1 speaking rate significantly predicts L2 speaking rate. Two measurements of speaking rate were automatically extracted from recordings of read and spontaneous speech by English monolinguals (n = 27) and bilinguals from ten L1 backgrounds (n = 86): speech rate (syllables/second), and articulation rate (syllables/second excluding silent pauses). Replicating prior work, L2 speaking rates were significantly slower than L1 speaking rates both across-groups (monolinguals' L1 English vs bilinguals' L2 English), and across L1 and L2 within bilinguals. Critically, within the bilingual group, L1 speaking rate significantly predicted L2 speaking rate, suggesting that a significant portion of inter-talker variation in L2 speech is derived from inter-talker variation in L1 speech, and that individual variability in L2 spoken language production may be best understood within the context of individual variability in L1 spoken language production.

Dimension-Based Statistical Learning Affects Both Speech Perception and Production

Multiple acoustic dimensions signal speech categories. However, dimensions vary in their informativeness; some are more diagnostic of category membership than others. Speech categorization reflects these dimensional regularities such that diagnostic dimensions carry more "perceptual weight" and more effectively signal category membership to native listeners. Yet perceptual weights are malleable. When short-term experience deviates from long-term language norms, such as in a foreign accent, the perceptual weight of acoustic dimensions in signaling speech category membership rapidly adjusts. The present study investigated whether rapid adjustments in listeners' perceptual weights in response to speech that deviates from the norms also affects listeners' own speech productions. In a word recognition task, the correlation between two acoustic dimensions signaling consonant categories, fundamental frequency (F0) and voice onset time (VOT), matched the correlation typical of English, and then shifted to an "artificial accent" that reversed the relationship, and then shifted back. Brief, incidental exposure to the artificial accent caused participants to down-weight perceptual reliance on F0, consistent with previous research. Throughout the task, participants were intermittently prompted with pictures to produce these same words. In the block in which listeners heard the artificial accent with a reversed F0 × VOT correlation, F0 was a less robust cue to voicing in listeners' own speech productions. The statistical regularities of short-term speech input affect both speech perception and production, as evidenced via shifts in how acoustic dimensions are weighted.

Cross-Linguistic Influence in the Bilingual Mental Lexicon: Evidence of Cognate Effects in the Phonetic Production and Processing of a Vowel Contrast

The present study examines cognate effects in the phonetic production and processing of the Catalan back mid-vowel contrast (/o/-/ɔ/) by 24 early and highly proficient Spanish-Catalan bilinguals in Majorca (Spain). Participants completed a picture-naming task and a forced-choice lexical decision task in which they were presented with either words (e.g., /bɔsk/ "forest") or non-words based on real words, but with the alternate mid-vowel pair in stressed position ((*)/bosk/). The same cognate and non-cognate lexical items were included in the production and lexical decision experiments. The results indicate that even though these early bilinguals maintained the back mid-vowel contrast in their productions, they had great difficulties identifying non-words and real words based on the identity of the Catalan mid-vowel. The analyses revealed language dominance and cognate effects: Spanish-dominants exhibited higher error rates than Catalan-dominants, and production and lexical decision accuracy were also affected by cognate status. The present study contributes to the discussion of the organization of early bilinguals' dominant and non-dominant sound systems, and proposes that exemplar theoretic approaches can be extended to include bilingual lexical connections that account for the interactions between the phonetic and lexical levels of early bilingual individuals.

Can Nonnative Speakers Reduce English Vowels in a Native-Like Fashion? Evidence from L1-Spanish L2-English Bilinguals

This paper investigates the production of English unstressed vowels by two groups of early (ESp) and late Spanish (LSp) bilinguals and a control group of native English (NE) monolinguals. Three acoustic measurements were obtained: duration and intensity ratios of unstressed to stressed vowels, normalized vowel formants and euclidean distances. Both groups of bilinguals showed significantly fewer differences in duration between stressed and unstressed vowels than the NE monolinguals. Intensity differences depended on whether the stress pattern of the target English words matched the stress pattern of their Spanish cognates. As for vowel quality, the early bilinguals reduced the unstressed vowels, which clustered around the midcenter area of the vowel space, in the same fashion as the NE monolinguals, suggesting that vowel reduction might be operating at the phonological level. However, the late bilinguals showed a context-dependent, phonetic-level pattern with vowels that were more peripheral in the vowel space.

Vowel development in an emergent Mandarin-English bilingual child: a longitudinal study

This longitudinal case study documents the emergence of bilingualism in a young monolingual Mandarin boy on the basis of an acoustic analysis of his vowel productions recorded via a picture-naming task over 20 months following his enrollment in an all-English (L2) preschool at the age of 3;7. The study examined (1) his initial L2 vowel space, (2) the process of L1-L2 separation, and (3) his L1 vowel system in relation to L2. The child initially utilized his L1 base in building the L2 vowel system. The L1-L2 separation started from a drastic restructuring of his working vowel space to create maximal contrast between the two languages. Meanwhile, L1 developmental processes and influence of L2 on L1 were also in effect. The developmental profile of this child uncovered strategies sequential bilingual children may use to restructure their phonetic space and construct a new system of contrasts in L2.

Prosodic Realization of Focus in Bilingual Production of Southern Min and Mandarin

Previously post-focus compression (PFC) - the lowering of fundamental frequency (F0) and intensity of post-focal words to below those of the same words in identical sentences with neutral focus - was found in Beijing Mandarin but not in Taiwan Southern Min and Taiwan Mandarin. This study investigated whether the presence of PFC would vary with age and language use of societal bilinguals of Southern Min and Mandarin. Three groups of bilingual speakers of Quanzhou Southern Min and Mandarin, age around 20, 40 and 60, were examined for their prosodic realization of focus. All the speakers acquired Southern Min first, followed by Mandarin in childhood, but the younger speakers used more Mandarin than the older speakers. Comparisons of duration, intensity and F0 in focused, prefocus and post-focus words indicated that all groups produced Taiwan-like focus, i.e., without PFC, in Southern Min, but the youngest group produced Beijing-like PFC in Mandarin. These findings reveal that increased language experience, such as greater amount of second language (L2) use, correlates with increased ability to produce native-like PFC in L2, suggesting that PFC can be used as an indicator in assessing L2 speech acquisition.

Fine-grained and probabilistic cross-linguistic influence in the pronunciation of cognates: Evidence from corpus-based spontaneous conversation and experimentally elicited data

The present study examines variable realizations of Spanish word-initial voiced and voiceless dental stops in Spanish-English cognate pairs. Employing a variationist approach to naturalistic data, we report significantly decreased likelihood of reduced articulations of word-initial /d/ in cognates in spontaneous bilingual Puerto Rican discourse, and no such probabilistic effect for cognates in monolingual Spanish of the same speech community. Using experimentally controlled elicited data of Spanish word-initial /t/, we also find evidence of significant fine-grained effects of English on the articulations of Spanish cognates in the form of lengthened VOT for Spanish-English bilinguals. These results indicate that cross-language lexical connections affect phonetic categories in the speech production of Spanish-English bilinguals. It is proposed that both fine-grained and probabilistic effects of the phonology of one language on another can be explained within the Exemplar Model of Lexical Representation.

The perception of the French /s/-/ʃ/ contrast in early Creole-French bilinguals

One particularity of the Mauritian Creole language is that there is no contrastive distinction between the consonants /s/ and /ʃ/, which are both pronounced /s/ in Creole. In this study, we examined the identification performance of the /s/-/ʃ/ contrast by Mauritian Creole-French bilinguals who have been exposed to French before 7 years of age, and who have been raised in a highly Creole-French bilingual society. The results showed that most of our bilingual participants identify the /s/ and /ʃ/ consonants like native French speakers. It also appeared that the way in which the two consonants are categorized can be manipulated by introducing subtle changes in the information these participants were given about the identity of the speaker that produced the stimuli. Our results are in accordance with recent studies showing native-like performance in bilinguals on a categorization task and, importantly, extend these findings to speakers of a Creole language. In addition, these results show that speech sound categorization can be influenced by information about the speaker's social identity and thus argue for models that postulate rich speech sound representations.

Age of acquisition and allophony in Spanish-English bilinguals

This study examines age of acquisition (AoA) in Spanish-English bilinguals' phonetic and phonological knowledge of /l/ in English and Spanish. In English, the lateral approximant /l/ varies in darkness by context [based on the second formant (F2) and the difference between F2 and the first formant (F1)], but the Spanish /l/ does not. Further, English /l/ is overall darker than Spanish /l/. Thirty-eight college-aged adults participated: 11 Early Spanish-English bilinguals who learned English before the age of 5 years, 14 Late Spanish-English bilinguals who learned English after the age of 6 years, and 13 English monolinguals. Participants' /l/ productions were acoustically analyzed by language and context. The results revealed a Spanish-to-English phonetic influence on /l/ productions for both Early and Late bilinguals, as well as an English-to-Spanish phonological influence on the patterning of /l/ for the Late Bilinguals. These findings are discussed in terms of the Speech Learning Model and the effect of AoA on the interaction between a bilingual speaker's two languages.

Vowel category formation in Korean-English bilingual children

PURPOSE

A previous investigation (Lee & Iverson, 2012) found that English and Korean stop categories were fully distinguished by Korean-English bilingual children at 10 years of age but not at 5 years of age. The present study examined vowels produced by Korean-English bilingual children of these same ages to determine whether and when bilinguals establish distinct vowel categories across their 2 languages.

METHOD

Both English and Korean vowels produced by 40 Korean-English bilingual children (5 and 10 years of age) were examined in terms of 1st formant frequency (F1) and 2nd formant frequency (F2), vowel duration, and F1 and F2 formant trajectories.

RESULTS

Formant frequencies of vowels produced by the bilingual children were similar to those of monolingual English and Korean children. The bilinguals distinguished vowel categories across languages using both the assimilation and dissimilation mechanisms as identified by Flege, Schirru, and MacKay (2003).

CONCLUSIONS

Vowel categories developed earlier than stops in bilingual children because vowels were typically acquired earlier than consonants. The results of this study suggest that detailed phonetic categories do not form across the board and that bilingual children may invoke multidimensional representations of phonetic categories.

Influence of L2 proficiency on kinematic duration of single words: Real and novel word production by Bengali-English speakers

The study explored the influence of second language proficiency on the kinematic duration of single words. Participants produced real and novel words with variable stress targets (e.g., trochaic and iambic) embedded in first language (L1) and second language (L2) sentence frames. Participants were monolingual English speakers (n=10) and Bengali-English bilinguals with early exposure to English (n=10) and late exposure to English (n=10). Bengali was the L1 and English was the L2 for all 20 bilingual participants. Duration of lip movements for the target real and novel words was analysed. Results suggest that kinematic duration of single words was not influenced by speakers' L2 proficiency. However, L2 proficiency influenced foreign accent ratings for the real words, but not the novel words. Kinematic duration and perception of accent were not correlated, which might imply that accent reduction might not always be a direct consequence of shorter word duration.

Production of a Catalan-specific vowel contrast by early Spanish-Catalan bilinguals

The present study investigates the acoustics (F1 × F2) of Catalan and Spanish mid-back vowels as produced by highly proficient, early Spanish-Catalan bilinguals residing on the island of Majorca, a bilingual speech community. Majorcan Catalan has two phonemic mid-back vowels in stressed positions (/o/ and /c/) while Spanish possesses only one (/o/). Two groups of bilinguals were recruited and asked to produce materials in both languages - one group of Spanish dominant and one of Catalan-dominant speakers. It was first found that Catalan and Spanish /o/ are virtually indistinguishable. Catalan /c/ is lower and more fronted than the other two vowels. Spanish-dominant bilinguals were found to differ from Catalan-dominant ones in that they did not produce the Catalan-specific /o/-/c/ contrast in their speech; that is, they produced a single, merged Catalan mid-back vowel. A within-subjects analysis of first- and second-language mid-back vowels further suggested, for Spanish-dominant bilinguals, that they had developed a separate vowel category to accommodate their single, merged Catalan mid-back vowel; that is, they possessed a two-category mid-back vowel system, i.e. one for their Spanish /o/ and one for their merged Catalan /o/ + /c/. Potential explanations and theoretical implications are discussed.

A one-year longitudinal study of English and Japanese vowel production by Japanese adults and children in an English-speaking setting

The effect of age of acquisition on first- and second-language vowel production was investigated. Eight English vowels were produced by Native Japanese (NJ) adults and children as well as by age-matched Native English (NE) adults and children. Productions were recorded shortly after the NJ participants' arrival in the USA and then one year later. In agreement with previous investigations [Aoyama, et al., J. Phon. 32, 233-250 (2004)], children were able to learn more, leading to higher accuracy than adults in a year's time. Based on the spectral quality and duration comparisons, NJ adults had more accurate production at Time 1, but showed no improvement over time. The NJ children's productions, however, showed significant differences from the NE children's for English "new" vowels /ɪ/, /ε/, /ɑ/, /ʌ/ and /ʊ/ at Time 1, but produced all eight vowels in a native-like manner at Time 2. An examination of NJ speakers' productions of Japanese /i/, /a/, /u/ over time revealed significant changes for the NJ Child Group only. Japanese /i/ and /a/ showed changes in production that can be related to second language (L2) learning. The results suggest that L2 vowel production is affected importantly by age of acquisition and that there is a dynamic interaction, whereby the first and second language vowels affect each other.

English Speech Acquisition in 3- to 5-Year-Old Children Learning Russian and English

Purpose

English speech acquisition in Russian–English (RE) bilingual children was investigated, exploring the effects of Russian phonetic and phonological properties on English single-word productions. Russian has more complex consonants and clusters and a smaller vowel inventory than English.

Method

One hundred thirty-seven single-word samples were phonetically transcribed from 14 RE and 28 English-only (E) children, ages 3;3 (years;months) to 5;7. Language and age differences were compared descriptively for phonetic inventories. Multivariate analyses compared phoneme accuracy and error rates between the two language groups.

Results

RE children produced Russian-influenced phones in English, including palatalized consonants and trills, and demonstrated significantly higher rates of trill substitution, final devoicing, and vowel errors than E children, suggesting Russian language effects on English. RE and E children did not differ in their overall production complexity, with similar final consonant deletion and cluster reduction error rates, similar phonetic inventories by age, and similar levels of phonetic complexity. Both older language groups were more accurate than the younger language groups.

Conclusions

We observed effects of Russian on English speech acquisition; however, there were similarities between the RE and E children that have not been reported in previous studies of speech acquisition in bilingual children. These findings underscore the importance of knowing the phonological properties of both languages of a bilingual child in assessment.

Cross language phonetic influences on the speech of French-English bilinguals

We examined the voice onset times (VOTs) of monolingual and bilingual speakers of English and French to address the question whether cross language phonetic influences occur particularly in simultaneous bilinguals (that is, speakers who learned both languages from birth). Speakers produced sentences in which there were target words with initial /p/, /t/ or /k/. In French, natively bilingual speakers produced VOTs that were significantly longer than those of monolingual French speakers. French VOTs were even longer in bilingual speakers who learned English before learning French. The outcome was analogous in English speech. Natively bilingual speakers produced shorter English VOTs than monolingual speakers. English VOTs were even shorter in the speech of bilinguals who learned French before English. Bilingual speakers had significantly longer VOTs in their English speech than in their French. Accordingly, the cross language effects do not occur because natively bilingual speakers adopt voiceless stop categories intermediate between those of native English and French speakers that serve both languages. Monolingual speakers of French or English in Montreal had VOTs nearly identical respectively to those of monolingual Parisian French speakers and those of monolingual Connecticut English speakers. These results suggest that mere exposure to a second language does not underlie the cross language phonetic effect; however, these findings must be resolved with others that appear to show an effect of overhearing.

Discrimination of coronal stops by bilingual adults: the timing and nature of language interaction

The current study was designed to investigate the timing and nature of interaction between the two languages of bilinguals. For this purpose, we compared discrimination of Canadian French and Canadian English coronal stops by simultaneous bilingual, monolingual and advanced early L2 learners of French and English. French /d/ is phonetically described as dental whereas English /d/ is described as alveolar. Using a categorial AXB task, the performance of all four groups was compared to chance and to the performance of native Hindi listeners. Hindi listeners performed well above chance in discriminating French and English /d/-initial syllables. The discrimination performance of advanced early L2 learners, but not simultaneous bilinguals, was consistent with one merged category for coronal stops in the two languages. The data provide evidence for interaction in L2 learners as well as simultaneous bilinguals; however, the nature of the interaction is different in the two groups.

Native Thai speakers' acquisition of English word stress patterns

The influence of syllabic structure, lexical class and stress patterns of known words on the acquisition of the English stress system was investigated in ten native Thai speakers. All participants were adult learners of English with an average length of residence in the US of 1.4 years. They were asked to produce and give perceptual judgments on 40 English non-words of varying syllabic structures in noun and verb sentence frames. Results of the production data suggested that syllables with a long vowel attracted stress more often than syllables containing a short vowel and nouns received initial stress more often than verbs. Additionally, regression analyses with the three factors as predictors suggested that Thai participants' pattern of stress assignment on non-words was significantly influenced by the stress patterns of phonologically similar real words. These results were compared and contrasted to those found in previous work with Spanish-English and Korean-English bilinguals.

Phonological systems in bilinguals: age of learning effects on the stop consonant systems of Korean-English bilinguals

Interaction of Korean and English stop systems in Korean-English bilinguals as a function of age of acquisition (AOA) of English was investigated. It was hypothesized that early bilinguals (mean AOA=3.8 years) would more likely be native-like in production of English and Korean stops and maintain greater independence between Korean and English stop systems than late bilinguals (mean AOA=21.4 years). Production of Korean and English stops was analyzed in terms of three acoustic-phonetic properties: voice-onset time, amplitude difference between the first two harmonics, and fundamental frequency. Late bilinguals were different from English monolinguals for English voiceless and voiced stops in all three properties. As for Korean stops, late bilinguals were different from Korean monolinguals for fortis stops in voice-onset time. Early bilinguals were not different from the monolinguals of either language. Considering the independence of the two stop systems, late bilinguals seem to have merged English voiceless and Korean aspirated stops and produced English voiced stops with similarities to both Korean fortis and lenis stops, whereas early bilinguals produced five distinct stop types. Thus, the early bilinguals seem to have two independent stop systems, whereas the late bilinguals likely have a merged Korean-English system.

Interaction of native- and second-language vowel system(s) in early and late bilinguals

The objective of this study was to determine how bilinguals' age at the time of language acquisition influenced the organization of their phonetic system(s). The productions of six English and five Korean vowels by English and Korean monolinguals were compared to the productions of the same vowels by early and late Korean-English bilinguals varying in amount of exposure to their second language. Results indicated that bilinguals' age profoundly influenced both the degree and the direction of the interaction between the phonetic systems of their native (L1) and second (L2) languages. In particular, early bilinguals manifested a bidirectional L1-L2 influence and produced distinct acoustic realizations of L1 and L2 vowels. Late bilinguals, however, showed evidence of a unidirectional influence of the L1 on the L2 and produced L2 vowels that were "colored" by acoustic properties of their L1. The degree and direction of L1-L2 influences in early and late bilinguals appeared to depend on the degree of acoustic similarity between L1 and L2 vowels and the length of their exposure to the L2. Overall, the findings underscored the complex nature of the restructuring of the L1-L2 phonetic system(s) in bilinguals.

Learning foreign vowels

Two hypotheses have recently been put forward to account for listeners' ability to distinguish and learn contrasts between speech sounds in foreign languages. First, Best's Perceptual Assimilation Model and Flege's Speech Learning Model both predict that the ease with which a listener can tell one non-native phoneme from another varies directly with the extent to which these sounds assimilate to different native phonemes (Best, 1994; also Best, McRoberts, & Goodell, 2001; Flege, 1991). Second, Logan, Lively, & Pisoni (1991) have argued that training listeners to identify non-native phonemes teaches them sets of exemplars rather than more abstract distinctive feature values. I report here the results of three sets of experiments designed to test these hypotheses, in which American English listeners were trained to categorize German nonlow vowels. The first set of experiments show that some instances of the same contrast between German vowels are more easily discriminated than others, a result incompatible with the predictions of either Best's or Flege's models, but compatible with the alternative category recognition interpretation. The second set of experiments reveals effects of contextual and speaker variation on listeners' ability to learn [tense] but not [high] contrasts between foreign vowels, and are thus at least partly compatible with an exemplar model of foreign category learning (Pisoni, Lively, & Logan, 1994; also Nosofsky, 1986). The third set of experiments compares the predictions of Nosofsky's (1986) selective attention exemplar model of category learning with those of a feature learning model in tests of listeners' learning the natural classes to which the German vowels belong. The results are mixed: listeners learned the features that define the natural classes of [+/- high] and [+/- back] vowels, but could have learned either the feature that defines the natural classes of [+/- tense] vowels or sets of [+/- tense] exemplars. Natural classes defined by abstract distinctive feature values are thus learnable, even if their membership is phonetically polymorphous.