Production of French vowels by American-English learners of French: language experience, consonantal context, and the perception-production relationship

Effects of Speech Cues on Acoustics and Intelligibility of Korean-Speaking Children With Cerebral Palsy

PURPOSE

Reduced speech intelligibility is often a hallmark of children with dysarthria secondary to cerebral palsy (CP), but effects of speech strategies for increasing intelligibility are understudied, especially in children who speak languages other than English. This study examined the effects of (the Korean translation of) two cues, "speak with your big mouth" and "speak with your strong voice," on speech acoustics and intelligibility of Korean-speaking children with CP.

METHOD

Fifteen Korean-speaking children with CP repeated words and sentences in habitual, big mouth, and strong voice conditions. Acoustic analyses were performed and intelligibility was assessed by means of 90 blinded listeners' ease-of-understanding (EoU) ratings and percentage of words correctly transcribed (PWC).

RESULTS

In response to both cues, children's vocal intensity and utterance duration increased significantly and differentially, whereas their vowel space area gains did not reach statistical significance. EoU increased significantly in the big mouth condition at word, but not sentence, level, whereas in the strong voice condition, EoU increased significantly at both levels. PWC increases were not statistically significant. Considerable variability in children's responses to cues was noted overall.

CONCLUSIONS

Korean-speaking children with CP modify their speech styles differentially when provided with cues aimed to increase their articulatory working space and vocal intensity. The results provide preliminary support for the use of the strong voice cue, in particular, to increase EoU. While the findings do not offer conclusive evidence of the intelligibility benefits of these cues, investigation with a larger sample size should provide further insight into optimal cueing strategies for increasing intelligibility in this population. Implications for language-specific versus language-independent treatment approaches are discussed.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25521052.

The Articulatory and Acoustic Representation of Second-Language French Vowels

This study examines how L1 English-L2 French learners use L1 articulatory and acoustic categories to produce L2 vowels that are both similar to and different from their L1 vowels. Previous studies examining the relationship between L1 and L2 sound inventories have found that learners reuse L1 phone categories to produce L2 phones that are perceived as similar, but importantly, there is a lack of articulatory data included in these types of studies, which has reinforced the assumption that vowel categories can be solely represented by their acoustic properties. The present study uses ultrasound tongue imaging data and videos of lip rounding in addition to acoustic data to examine how L1 English-L2 French learners produce the French vowels /i y u e ø o/ compared with their English vowels /i u e o/. The results focus on individual paths to category formation to show how learners articulate L2 vowels, and reveal that they tend to reuse L1 tongue body gestures to produce the French vowels /i u e o/, and lip rounding gestures to produce the round vowels /y u o/. This study demonstrates that transfer of articulatory gestures depends on vowel quality and emphasizes the importance of using articulatory data to inform theories of L2 category formation.

Bad maps may not always get you lost: Lexically driven perceptual recalibration for substituted phonemes

The speech perception system adjusts its phoneme categories based on the current speech input and lexical context. This is known as lexically driven perceptual recalibration, and it is often assumed to underlie accommodation to non-native accented speech. However, recalibration studies have focused on maximally ambiguous sounds (e.g., a sound ambiguous between "sh" and "s" in a word like "superpower"), a scenario that does not represent the full range of variation present in accented speech. Indeed, non-native speakers sometimes completely substitute a phoneme for another, rather than produce an ambiguous segment (e.g., saying "shuperpower"). This has been called a "bad map" in the literature. In this study, we scale up the lexically driven recalibration paradigm to such cases. Because previous research suggests that the position of the critically accented phoneme modulates the success of recalibration, we include such a manipulation in our study. And to ensure that participants treat all critical items as words (an important point for successful recalibration), we use a new exposure task that incentivizes them to do so. Our findings suggest that while recalibration is most robust after exposure to ambiguous sounds, it also occurs after exposure to bad maps. But interestingly, positional effects may be reversed: recalibration was more likely for ambiguous sounds late in words, but more likely for bad maps occurring early in words. Finally, a comparison of an online versus in-lab version of these conditions shows that experimental setting may have a non-trivial effect on the results of recalibration studies.

Individual variability and the effect of personality on non-native speech shadowing

The present study examines whether personality traits are predictive of success in non-native speech shadowing. Seventy-four monolingual native speakers of English shadowed French words containing high rounded vowels /y/ and /u/ produced by a native French model talker and provided information about their personality through a Big Five Inventory questionnaire. Acoustic analyses support the idea that some personality traits predicted the degree of similarity between the talkers and the model. In this case, shadowed productions by talkers who had higher scores in extraversion and neuroticism were significantly more similar to the model than those who had lower scores.

Listeners' Linguistic Experience Affects the Degree of Perceived Nativeness of First Language Pronunciation

The aim of this study was to explore if and to what extent Austrian-English late sequential bilinguals who have been living in a second language (L2) environment for several decades are perceived to sound native in their first language (L1) when being compared to monolingual Austrian German (AG) control speakers. Furthermore, this investigation aimed to identify if listeners differ in their judgments of nativeness of L1 pronunciation depending on their own language background. For this purpose, two groups of native Austrian German listeners (N = 30 each), who differed regarding their linguistic background (Austrian German monolingual and Austrian German-English bilingual listeners) were asked to rate spontaneous speech samples produced by Austrian English bilingual and Austrian German monolingual speakers. Results showed that the bilingual L1 speech was perceived to sound overall less native compared to monolingual control speech. It was further observed that the two listener groups significantly differed in their perception of nativeness: Bilingual listeners were overall less likely to judge bilingual L1 pronunciation to sound non-native compared to monolingual listeners. To date, this is the first study to show that listener experience influences their perception of nativeness of L1 pronunciation and, thus, adds a new dimension to the notion of the native speaker.

Speech Treatment Effects on Narrative Intelligibility in French-Speaking Children With Dysarthria

Purpose This study examined the effects of Speech Intelligibility Treatment (SIT) on intelligibility and naturalness of narrative speech produced by francophone children with dysarthria due to cerebral palsy. Method Ten francophone children with dysarthria were randomized to one of two treatments, SIT or Hand-Arm Bimanual Intensive Therapy Including Lower Extremities, a physical therapy (PT) treatment. Both treatments were conducted in a camp setting and were comparable in dosage. The children were recorded pre- and posttreatment producing a story narrative. Intelligibility was measured by means of 60 blinded listeners' orthographic transcription accuracy (percentage of words transcribed correctly). The listeners also rated the children's naturalness on a visual analogue scale. Results A significant pre- to posttreatment increase in intelligibility was found for the SIT group, but not for the PT group, with great individual variability observed among the children. No significant changes were found for naturalness ratings or sound pressure level in the SIT group or the PT group posttreatment. Articulation rate increased in both treatment groups, although not differentially across treatments. Conclusions Findings from this first treatment study on intelligibility in francophone children with dysarthria suggest that SIT shows promise for increasing narrative intelligibility in this population. Acoustic contributors to the increased intelligibility remain to be explored further. Supplemental Material https://doi.org/10.23641/asha.14161943.

Perceptual and Acoustic Effects of Dual-Focus Speech Treatment in Children With Dysarthria

Purpose Children with dysarthria secondary to cerebral palsy may experience reduced speech intelligibility and diminished communicative participation. However, minimal research has been conducted examining the outcomes of behavioral speech treatments in this population. This study examined the effect of Speech Intelligibility Treatment (SIT), a dual-focus speech treatment targeting increased articulatory excursion and vocal intensity, on intelligibility of narrative speech, speech acoustics, and communicative participation in children with dysarthria. Method American English-speaking children with dysarthria (n = 17) received SIT in a 3-week summer camplike setting at Columbia University. SIT follows motor-learning principles to train the child-friendly, dual-focus strategy, "Speak with your big mouth and strong voice." Children produced a story narrative at baseline, immediate posttreatment (POST), and at 6-week follow-up (FUP). Outcomes were examined via blinded listener ratings of ease of understanding (n = 108 adult listeners), acoustic analyses, and questionnaires focused on communicative participation. Results SIT resulted in significant increases in ease of understanding at POST, that were maintained at FUP. There were no significant changes to vocal intensity, speech rate, or vowel spectral characteristics, with the exception of an increase in second formant difference between vowels following SIT. Significantly enhanced communicative participation was evident at POST and FUP. Considerable variability in response to SIT was observed between children. Conclusions Dual-focus treatment shows promise for improving intelligibility and communicative participation in children with dysarthria, although responses to treatment vary considerably across children. Possible mechanisms underlying the intelligibility gains, enhanced communicative participation, and variability in treatment effects are discussed.

Longitudinal Developments in Bilingual Second Language Acquisition and First Language Attrition of Speech: The Case of Arnold Schwarzenegger

The purpose of this investigation was to trace first (L1) and second language (L2) segmental speech development in the Austrian German–English late bilingual Arnold Schwarzenegger over a period of 40 years, which makes it the first study to examine a bilingual’s speech development over several decades in both their languages. To this end, acoustic measurements of voice onset time (VOT) durations of word-initial plosives (Study 1) and formant frequencies of the first and second formant of Austrian German and English monophthongs (Study 2) were conducted using speech samples collected from broadcast interviews. The results of Study 1 showed a merging of Schwarzenegger’s German and English voiceless plosives in his late productions as manifested in a significant lengthening of VOT duration in his German plosives, and a shortening of VOT duration in his English plosives, closer to L1 production norms. Similar findings were evidenced in Study 2, revealing that some of Schwarzenegger’s L1 and L2 vowel categories had moved closer together in the course of L2 immersion. These findings suggest that both a bilingual’s first and second language accent is likely to develop and reorganize over time due to dynamic interactions between the first and second language system.

The Role of Acoustic Similarity and Non-Native Categorisation in Predicting Non-Native Discrimination: Brazilian Portuguese Vowels by English vs. Spanish Listeners

This study tests whether Australian English (AusE) and European Spanish (ES) listeners differ in their categorisation and discrimination of Brazilian Portuguese (BP) vowels. In particular, we investigate two theoretically relevant measures of vowel category overlap (acoustic vs. perceptual categorisation) as predictors of non-native discrimination difficulty. We also investigate whether the individual listener’s own native vowel productions predict non-native vowel perception better than group averages. The results showed comparable performance for AusE and ES participants in their perception of the BP vowels. In particular, discrimination patterns were largely dependent on contrast-specific learning scenarios, which were similar across AusE and ES. We also found that acoustic similarity between individuals’ own native productions and the BP stimuli were largely consistent with the participants’ patterns of non-native categorisation. Furthermore, the results indicated that both acoustic and perceptual overlap successfully predict discrimination performance. However, accuracy in discrimination was better explained by perceptual similarity for ES listeners and by acoustic similarity for AusE listeners. Interestingly, we also found that for ES listeners, the group averages explained discrimination accuracy better than predictions based on individual production data, but that the AusE group showed no difference.

Toward a new model for speech perception: the Universal Perceptual Model (UPM) of second language

Several speech models have been formed in the past aiming to predict the abilities of nonnative listeners or learners in perceiving and producing speech sounds. The present paper proposes a new model for speech perception, the Universal Perceptual Model of Second Language (henceforth, UPM). UPM assumes that second language phone acquisition is strongly affected by the speakers' native language but still the window of phone learning is open due to the universality of speech sounds. Also, it supports that second language phones are initially activated as disoriented phonetic units. In this paper, we provide some initial insights into the predictability of the model. UPM uses degrees of overlap and chance criteria to form its predictions. We recruited Cypriot Greek novice learners of Italian who participated in two psychoacoustic tasks in which they classified and discriminated Italian vowels, respectively. The findings demonstrated that the degree of overlap between two nonnative phones may be a good predictor of the speakers' discrimination accuracy over these phones. UPM might be a useful model which aims to better explain speech perception mechanisms and patterns of speech acquisition.

Effects of speech cues in French-speaking children with dysarthria

BACKGROUND

Articulatory excursion and vocal intensity are reduced in many children with dysarthria due to cerebral palsy (CP), contributing to the children's intelligibility deficits and negatively affecting their social participation. However, the effects of speech-treatment strategies for improving intelligibility in this population are understudied, especially for children who speak languages other than English. In a cueing study on English-speaking children with dysarthria, acoustic variables and intelligibility improved when the children were provided with cues aimed to increase articulatory excursion and vocal intensity. While French is among the top 20 most spoken languages in the world, dysarthria and its management in French-speaking children are virtually unexplored areas of research. Information gleaned from such research is critical for providing an evidence base on which to provide treatment.

AIMS

To examine acoustic and perceptual changes in the speech of French-speaking children with dysarthria, who are provided with speech cues targeting greater articulatory excursion (French translation of 'speak with your big mouth') and vocal intensity (French translation of 'speak with your strong voice'). This study investigated whether, in response to the cues, the children would make acoustic changes and listeners would perceive the children's speech as more intelligible.

METHODS & PROCEDURES

Eleven children with dysarthria due to CP (six girls, five boys; ages 4;11-17;0 years; eight with spastic CP, three with dyskinetic CP) repeated pre-recorded speech stimuli across three speaking conditions (habitual, 'big mouth' and 'strong voice'). Stimuli were sentences and contrastive words in phrases. Acoustic analyses were conducted. A total of 66 Belgian-French listeners transcribed the children's utterances orthographically and rated their ease of understanding on a visual analogue scale at sentence and word levels.

OUTCOMES & RESULTS

Acoustic analyses revealed significantly longer duration in response to the big mouth cue at sentence level and in response to both the big mouth and strong voice cues at word level. Significantly higher vocal sound-pressure levels were found following both cues at sentence and word levels. Both cues elicited significantly higher first-formant vowel frequencies and listeners' greater ease-of-understanding ratings at word level. Increases in the percentage of words transcribed correctly and in sentence ease-of-understanding ratings, however, did not reach statistical significance. Considerable variability between children was observed.

CONCLUSIONS & IMPLICATIONS

Speech cues targeting greater articulatory excursion and vocal intensity yield significant acoustic changes in French-speaking children with dysarthria. However, the changes may only aid listeners' ease of understanding at word level. The significant findings and great inter-speaker variability are generally consistent with studies on English-speaking children with dysarthria, although changes appear more constrained in these French-speaking children. What this paper adds What is already known on the subject According to the only study comparing effects of speech-cueing strategies on English-speaking children with dysarthria, intelligibility increases when the children are provided with cues aimed to increase articulatory excursion and vocal intensity. Little is known about speech characteristics in French-speaking children with dysarthria and no published research has explored effects of cueing strategies in this population. What this paper adds to existing knowledge This paper is the first study to examine the effects of speech cues on the acoustics and intelligibility of French-speaking children with CP. It provides evidence that the children can make use of cues to modify their speech, although the changes may only aid listeners' ease of understanding at word level. What are the potential or actual clinical implications of this work? For clinicians, the findings suggest that speech cues emphasizing increasing articulatory excursion and vocal intensity show promise for improving the ease of understanding of words produced by francophone children with dysarthria, although improvements may be modest. The variability in the responses also suggests that this population may benefit from a combination of such cues to produce words that are easier to understand.

Bidirectional influence on L1 Spanish and L2 English stop perception: The role of L2 experience

Previous research found that second language (L2) experience may cause an interaction between first language (L1) and L2 categories. This study examines the effect of L2 experience on L1 and L2 stop perception. Three groups of Spanish learners of English varying in L2 experience completed a /p/-/b/ identification task-which included stimuli varying along a Voice Onset Time continuum-in each language. Results suggested that L2 experience improves the perception of L2 stops, but that it also affects L1 perception. Moreover, all groups appeared to have a shared L1-L2 category for bilabial stops, as perception patterns did not differ between languages.

Perception-Production Links in Children's Speech

Purpose Child phonologists have long been interested in how tightly speech input constrains the speech production capacities of young children, and the question acquires clinical significance when children with hearing loss are considered. Children with sensorineural hearing loss often show differences in the spectral and temporal structures of their speech production, compared to children with normal hearing. The current study was designed to investigate the extent to which this problem can be explained by signal degradation. Method Ten 5-year-olds with normal hearing were recorded imitating 120 three-syllable nonwords presented in unprocessed form and as noise-vocoded signals. Target segments consisted of fricatives, stops, and vowels. Several measures were made: 2 duration measures (voice onset time and fricative length) and 4 spectral measures involving 2 segments (1st and 3rd moments of fricatives and 1st and 2nd formant frequencies for the point vowels). Results All spectral measures were affected by signal degradation, with vowel production showing the largest effects. Although a change in voice onset time was observed with vocoded signals for /d/, voicing category was not affected. Fricative duration remained constant. Conclusions Results support the hypothesis that quality of the input signal constrains the speech production capacities of young children. Consequently, it can be concluded that the production problems of children with hearing loss-including those with cochlear implants-can be explained to some extent by the degradation in the signal they hear. However, experience with both speech perception and production likely plays a role as well.

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.

Functional brain outcomes of L2 speech learning emerge during sensorimotor transformation

Sensorimotor transformation (ST) may be a critical process in mapping perceived speech input onto non-native (L2) phonemes, in support of subsequent speech production. Yet, little is known concerning the role of ST with respect to L2 speech, particularly where learned L2 phones (e.g., vowels) must be produced in more complex lexical contexts (e.g., multi-syllabic words). Here, we charted the behavioral and neural outcomes of producing trained L2 vowels at word level, using a speech imitation paradigm and functional MRI. We asked whether participants would be able to faithfully imitate trained L2 vowels when they occurred in non-words of varying complexity (one or three syllables). Moreover, we related individual differences in imitation success during training to BOLD activation during ST (i.e., pre-imitation listening), and during later imitation. We predicted that superior temporal and peri-Sylvian speech regions would show increased activation as a function of item complexity and non-nativeness of vowels, during ST. We further anticipated that pre-scan acoustic learning performance would predict BOLD activation for non-native (vs. native) speech during ST and imitation. We found individual differences in imitation success for training on the non-native vowel tokens in isolation; these were preserved in a subsequent task, during imitation of mono- and trisyllabic words containing those vowels. fMRI data revealed a widespread network involved in ST, modulated by both vowel nativeness and utterance complexity: superior temporal activation increased monotonically with complexity, showing greater activation for non-native than native vowels when presented in isolation and in trisyllables, but not in monosyllables. Individual differences analyses showed that learning versus lack of improvement on the non-native vowel during pre-scan training predicted increased ST activation for non-native compared with native items, at insular cortex, pre-SMA/SMA, and cerebellum. Our results hold implications for the importance of ST as a process underlying successful imitation of non-native speech.

Acoustic and Perceptual Consequences of Speech Cues for Children With Dysarthria

PURPOSE

Reductions in articulatory working space and vocal intensity have been linked to intelligibility deficits in children with dysarthria due to cerebral palsy. However, few studies have examined the outcomes of behavioral treatments aimed at these underlying impairments or investigated which treatment cues might best facilitate improved intelligibility. This study assessed the effects of cues targeting clear speech (i.e., "Speak with your big mouth") and greater vocal intensity (i.e., "Speak with your strong voice") on acoustic measures of speech production and intelligibility.

METHOD

Eight children with spastic dysarthria due to cerebral palsy repeated sentence- and word-level stimuli across habitual, big mouth, and strong voice conditions. Acoustic analyses were conducted, and 48 listeners completed orthographic transcription and scaled intelligibility ratings.

RESULTS

Both cues resulted in significant changes to vocal intensity and speech rate although the degree of change varied by condition. In a similar manner, perceptual analysis revealed significant improvements to intelligibility with both cues; however, at the single-word level, big mouth outperformed strong voice.

CONCLUSION

Children with dysarthria are capable of changing their speech styles differentially in response to cueing. Both the big mouth and strong voice cues hold promise as intervention strategies to improve intelligibility in this population.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.5116843.

Differences in the Association between Segment and Language: Early Bilinguals Pattern with Monolinguals and Are Less Accurate than Late Bilinguals

Early bilinguals often show as much sensitivity to L2-specific contrasts as monolingual speakers of the L2, but most work on cross-language speech perception has focused on isolated segments, and typically only on neighboring vowels or stop contrasts. In tasks that include sounds in context, listeners’ success is more variable, so segment discrimination in isolation may not adequately represent the phonetic detail in stored representations. The current study explores the relationship between language experience and sensitivity to segmental cues in context by comparing the categorization patterns of monolingual English listeners and early and late Spanish–English bilinguals. Participants categorized nonce words containing different classes of English- and Spanish-specific sounds as being more English-like or more Spanish-like; target segments included phonemic cues, cues for which there is no analogous sound in the other language, or phonetic cues, cues for which English and Spanish share the category but for which each language varies in its phonetic implementation. Listeners’ language categorization accuracy and reaction times were analyzed. Our results reveal a largely uniform categorization pattern across listener groups: Spanish cues were categorized more accurately than English cues, and phonemic cues were easier for listeners to categorize than phonetic cues. There were no differences in the sensitivity of monolinguals and early bilinguals to language-specific cues, suggesting that the early bilinguals’ exposure to Spanish did not fundamentally change their representations of English phonology. However, neither did the early bilinguals show more sensitivity than the monolinguals to Spanish sounds. The late bilinguals however, were significantly more accurate than either of the other groups. These findings indicate that listeners with varying exposure to English and Spanish are able to use language-specific cues in a nonce-word language categorization task. Differences in how, and not only when, a language was acquired may influence listener sensitivity to more difficult cues, and the advantage for phonemic cues may reflect the greater salience of categories unique to each language. Implications for foreign-accent categorization and cross-language speech perception are discussed, and future directions are outlined to better understand how salience varies across language-specific phonemic and phonetic cues.

Syllable Structure Universals and Native Language Interference in Second Language Perception and Production: Positional Asymmetry and Perceptual Links to Accentedness

The present study investigated how syllable structure differences between the first Language (L1) and the second language (L2) affect L2 consonant perception and production at syllable-initial and syllable-final positions. The participants were Mandarin-speaking college students who studied English as a second language. Monosyllabic English words were used in the perception test. Production was recorded from each Chinese subject and rated for accentedness by two native speakers of English. Consistent with previous studies, significant positional asymmetry effects were found across speech sound categories in terms of voicing, place of articulation, and manner of articulation. Furthermore, significant correlations between perception and accentedness ratings were found at the syllable onset position but not for the coda. Many exceptions were also found, which could not be solely accounted for by differences in L1-L2 syllabic structures. The results show a strong effect of language experience at the syllable level, which joins force with acoustic, phonetic, and phonemic properties of individual consonants in influencing positional asymmetry in both domains of L2 segmental perception and production. The complexities and exceptions call for further systematic studies on the interactions between syllable structure universals and native language interference with refined theoretical models to specify the links between perception and production in second language acquisition.

On the effects of L2 perception and of individual differences in L1 production on L2 pronunciation

The speech of late second language (L2) learners is generally marked by an accent. The dominant theoretical perspective attributes accents to deficient L2 perception arising from a transfer of L1 phonology, which is thought to influence L2 perception and production. In this study we evaluate the explanatory role of L2 perception in L2 production and explore alternative explanations arising from the L1 phonological system, such as for example, the role of L1 production. Specifically we examine the role of an individual’s L1 productions in the production of L2 vowel contrasts. Fourteen Spanish adolescents studying French at school were assessed on their perception and production of the mid-close/mid-open contrasts, /ø-œ/ and /e-ε/, which are, respectively, acoustically distinct from Spanish sounds, or similar to them. The participants’ native productions were explored to assess (1) the variability in the production of native vowels (i.e., the compactness of vowel categories in F1/F2 acoustic space), and (2) the position of the vowels in the acoustic space. The results revealed that although poorly perceived contrasts were generally produced poorly, there was no correlation between individual performance in perception and production, and no effect of L2 perception on L2 production in mixed-effects regression analyses. This result is consistent with a growing body of psycholinguistic and neuroimaging research that suggest partial dissociations between L2 perception and production. In contrast, individual differences in the compactness and position of native vowels predicted L2 production accuracy. These results point to existence of surface transfer of individual L1 phonetic realizations to L2 space and demonstrate that pre-existing features of the native space in production partly determine how new sounds can be accommodated in that space.

Perceptual confusions of American-English vowels and consonants by native Arabic bilinguals

This study investigated the perception of American-English (AE) vowels and consonants by young adults who were either (a) early Arabic-English bilinguals whose native language was Arabic or (b) native speakers of the English dialects spoken in the United Arab Emirates (UAE), where both groups were studying. In a closed-set format, participants were asked to identify 12 AE vowels presented in /hVd/ context and 20 AE consonants (C) in three vocalic contexts: /aCa/, /iCi/, and /uCu/. Both native Arabic and native English groups demonstrated high accuracy in identification of vowels (70 and 80% correct, respectively) and consonants (94 and 95% correct, respectively). For both groups, the least-accurately identified vowels were /o/, /(see text)/, /ae/, while most consonant errors were found for /(see text)/, which was most frequently confused with /v/. However, for both groups, identification of /(see text)/ was vocalic-context dependent, with most errors occurring in liCil context and fewest errors occurring in luCu/ context. Lack of significant group differences suggests that speech sound identification patterns, including phonetic context effects for /(see text)/, were influenced more by the local English dialects than by listeners' Arabic language background. The findings also demonstrate consistent perceptual error patterns among listeners despite considerable variation in their native and second language dialectal backgrounds.

Effects of EPG treatment for English consonant contrasts on L2 perception and production

Links between perception and production were investigated for two adult native speakers of Korean who participated in electropalatographic (EPG) treatment designed to teach phonological and articulatory contrasts between English /s/ - /ʃ/, /z/ - /ʤ/, and /l/ - /ɹ/. Participants were successful in learning to produce the English contrasts. Perception of English consonants was tested pre- and post-treatment. Post-treatment perception improved somewhat for treated consonants but not for untreated consonants, although perception was not directly trained.

Stronger accent following a stroke: the case of a trilingual with aphasia

This study documents patterns of change in speech production in a multilingual with aphasia following a cerebrovascular accident (CVA). EC, a right-handed Hebrew-English-French trilingual man, had a left fronto-temporo-parietal CVA, after which he reported that his (native) Hebrew accent became stronger in his (second language) English. Recordings of his pre- and post-CVA speech permitted an investigation of changes in his accent. In sentence- and segment-listening tasks, native American English listeners (n = 13 and 15, respectively) judged EC's pre- and post-CVA speech. EC's speech was perceived as more foreign-accented, slow, strained and hesitant, but not less intelligible, post-CVA. Acoustic analysis revealed less coarticulation and longer vowel- and word-durations post-CVA. This case extends knowledge about perceptual and acoustic changes in speech production in multilinguals following CVAs. It is suggested that EC's stronger accent post-CVA may have resulted from damage to the neuronal networks that led to impairment in his other language domains.

Production of phonetic and phonological contrast by heritage speakers of Mandarin

This study tested the hypothesis that heritage speakers of a minority language, due to their childhood experience with two languages, would outperform late learners in producing contrast: language-internal phonological contrast, as well as cross-linguistic phonetic contrast between similar, yet acoustically distinct, categories of different languages. To this end, production of Mandarin and English by heritage speakers of Mandarin was compared to that of native Mandarin speakers and native American English-speaking late learners of Mandarin in three experiments. In experiment 1, back vowels in Mandarin and English were produced distinctly by all groups, but the greatest separation between similar vowels was achieved by heritage speakers. In experiment 2, Mandarin aspirated and English voiceless plosives were produced distinctly by native Mandarin speakers and heritage speakers, who both put more distance between them than late learners. In experiment 3, the Mandarin retroflex and English palato-alveolar fricatives were distinguished by more heritage speakers and late learners than native Mandarin speakers. Thus, overall the hypothesis was supported: across experiments, heritage speakers were found to be the most successful at simultaneously maintaining language-internal and cross-linguistic contrasts, a result that may stem from a close approximation of phonetic norms that occurs during early exposure to both languages.