L2 Vowel Research Articles

Motoric Training Alters Speech Sound Perception and Production — Active Listening Training Does Not Lead into Learning Outcomes

Accurate speech-sound perception and production are prerequisites for communication in a non-native language. Earlier research has shown that new categorization and pronunciation patterns evolve in different learning settings and that these skills can be trained with various methods. We tested the effects of two types of training protocols on the production and identification of L2 vowels embedded in a pseudo-word context. Group 1 (Producers) participated in a listen and repeat training, where they produced the target stimulus /tᵾ:ti/ and the non-target stimulus /ty:ti/ after the example in a pseudo-randomized order; Group 2 (Listeners) was instructed to count the number of targets /tᵾ:ti/ in the same stimulus train without any motoric production movements. The results showed clearly that listen and repeat training led to plastic changes both in production and in identification, while no learning effects were obtained with the listening paradigm. This suggests a significant role of motoric experience in the acquisition of speech.

Distinctiveness and Assimilation in Vowel Perception in a Second Language.

Purpose The purpose of this study was to investigate how the distinctive establishment of 2nd language (L2) vowel categories (e.g., how distinctively an L2 vowel is established from nearby L2 vowels and from the native language counterpart in the 1st formant [F1] × 2nd formant [F2] vowel space) affected L2 vowel perception. Method Identification of 12 natural English monophthongs, and categorization and rating of synthetic English vowels /i/ and /ɪ/ in the F1 × F2 space were measured for Chinese-native (CN) and English-native (EN) listeners. CN listeners were also examined with categorization and rating of Chinese vowels in the F1 × F2 space. Results As expected, EN listeners significantly outperformed CN listeners in English vowel identification. Whereas EN listeners showed distinctive establishment of 2 English vowels, CN listeners had multiple patterns of L2 vowel establishment: both, 1, or neither established. Moreover, CN listeners' English vowel perception was significantly related to the perceptual distance between the English vowel and its Chinese counterpart, and the perceptual distance between the adjacent English vowels. Conclusions L2 vowel perception relied on listeners' capacity to distinctively establish L2 vowel categories that were distant from the nearby L2 vowels.

Individual Differences in L2 Speech Perception: The Role of Phonological Memory and Lipreading Ability

AbstractThe current study investigated the effects of individual differences in lipreading ability, working memory (WM), and phonological short‐term memory (PSTM) on second language (L2) speech perception. An L2 French vowel identification task was administered to 32 Australian English learners of French in audiovisual, audio‐only, and visual‐only conditions. Participants also completed tasks measuring their first language (L1) lipreading ability at the phoneme, word, and sentence level; a listening span task assessing their WM capacity; and a nonword repetition task assessing their PSTM. Overall, speech perception was significantly better in the audiovisual and audio‐only conditions, and large individual variability was observed in the lipreading, WM, and PSTM tasks. Results revealed a significant effect of PSTM on vowel perception scores in all modalities of presentation, but no effect of WM capacity was found. In addition, lipreading ability at the word level was found to be a predictor of accurate L2 vowel perception in the visual modality.

Changes in L2 production variability associated with visual biofeedback training

Previous research suggests that acoustic variability across repeated productions of a phoneme could index the robustness of speech motor plans. Variability at onset is thought to reflect robustness in feedforward control [1,2], while variability at midpoint may reflect the narrowness of sensory targets and/or speakers’ capacity for feedback correction [3]. In L2 production, speakers may show elevated variability at onset because of unfamiliar motor plans and at midpoint due to weak sensory targets [2]. This study investigated variability in L2 vowel production before and after a brief training incorporating visual biofeedback. We hypothesized that midpoint variability would decrease after training, reflecting refinement of the auditory target, whereas onset variability may remain unchanged because the limited training might not be sufficient to establish a robust feedforward plan. Sixty native English speakers received 1 h of biofeedback training to produce two Mandarin vowels (/y, u/). After training, both vowels showed decreased midpoint variability, but only /y/ showed reduced onset variability. In addition, for /u/ only, higher pre-training midpoint variability was correlated with greater improvement in accuracy (distance from native-speaker target). These results are discussed in connection with the differing relationships of Mandarin /y/ and /u/ to the English vowel inventory.Previous research suggests that acoustic variability across repeated productions of a phoneme could index the robustness of speech motor plans. Variability at onset is thought to reflect robustness in feedforward control [1,2], while variability at midpoint may reflect the narrowness of sensory targets and/or speakers’ capacity for feedback correction [3]. In L2 production, speakers may show elevated variability at onset because of unfamiliar motor plans and at midpoint due to weak sensory targets [2]. This study investigated variability in L2 vowel production before and after a brief training incorporating visual biofeedback. We hypothesized that midpoint variability would decrease after training, reflecting refinement of the auditory target, whereas onset variability may remain unchanged because the limited training might not be sufficient to establish a robust feedforward plan. Sixty native English speakers received 1 h of biofeedback training to produce two Mandarin vowels (/y, u/). After training, bo...

Effects of Individual difference and L1 phonology on the identification and discrimination of American English vowels by native Japanese and Korean listeners

Native speakers of Japanese and Korean identified and discriminated American English vowels /i, ɪ, ɛ, ae, ɑ, ʌ/ in four different consonantal contexts. These listeners also perceptually assimilated the American English vowels to their respective L1 vowel categories. In another session, these listeners produced /i, ɪ, ɛ, ae, ɑ, ʌ/ in two different conditions. They read aloud words on a list, and they repeated after native speakers' utterances. The results revealed that Korean listeners as well as Japanese listeners rely on durational difference to identify and discriminate /i/ and /ɪ/, but Korean listeners perceptually assimilated /i/ and /ɪ/ as roughly equally good exemplars of Korean high front vowel. Japanese listeners, on the other hand, perceived /ɪ/ as somewhat less ideal exemplar of Japanese high front vowel than /i/. However, those Japanese listeners who were sensitive to spectral differences did not outperform those who were less sensitive. Moreover, Japanese listeners sensitive to the spectral differences often misidentified /ɪ/ for /ɛ/. An MDS analysis revealed that in the identification task, listeners’ L1 phonology exercise a stronger influence than do individual differences, but in discrimination task, individual differences are as strong a factor as listeners’ L1 phonology.

Third-language learning affects bilinguals’ production in both their native languages: A longitudinal study of dynamic changes in L1, L2 and L3 vowel production

This study examined the impact of a study abroad (SA) English program on English and native vowel production. Basque-Spanish bilingual adolescents were assessed on their vowel production in English, Basque and Spanish before the SA program, the day after the program was completed, and four months later. The results revealed that after the SA program, participants’ English vowels were acoustically closer to English norms, revealing the effectiveness of SA programs in improving English vowel pronunciation. Yet, four months later, these benefits had faded, showing that regular input and active language use are required to maintain accurate pronunciation. SA also had effects on native production: bilingual participants showed assimilatory acoustic drift in both their languages towards the English vowel system; the extent of this drift was negatively correlated with improvements in English pronunciation. However, four months later, participants showed a ‘return’ drift towards their native norms. The results also revealed that usage frequency and switching habits played a ‘protective’ role: Frequent switching in bilinguals made the dominant native language less vulnerable to foreign-language influence. Our results suggest that factors related to the frequency and circumstances of native language use are key to authenticity in native language production.

Role of instruction in the perception of English high back vowels

This article aims to analyze whether formal instruction influences Brazilian speakers' perception of the English high back vowels contrast. There have been a few L2 pieces of research that focused on the instruction of specific vowel contrasts. Previous studies indicate that a single L1 category seems to be a source of difficulty to L2 vowel discrimination. However, some of these investigations did not focus on the role of instruction to such discrimination. The participants of the present study were 17 Brazilian speakers of Portuguese as L1, beginning learners of English, divided into experimental and control groups. The study included a perception pretest, a pronunciation instruction class, taught only to the experimental group, and a perception posttest. Results showed that experimental and control groups obtained similar results. Based on that, some factors were pointed to possibly explain this outcome, such as the duration of the pronunciation instruction, the possibility of participants learning with the pretest itself, the duration of the data collection, the participants' possible assimilation of the target contrast into a single category, and the interference of the mid central vowel /?/ used as a distractor in the data collection. On the other hand, a qualitative analysis revealed that all participants in the experimental group found the pronunciation instruction helpful. Such findings seem to agree entirely or in part with other similar studies' results.

The relationship between “native-like” L2 vowel production and perceptual judgments enhancement by native listeners

The relationship between second language (L2) vowel production as a function of L2 experience and its perceptual judgments by native listeners of the language was investigated to determine whether the production improvement in the specific acoustics of L2 vowels give rise to higher judgement accuracy. A total of 20 Mandarin Chinese differing in the L2 experience (6 months vs. 2 years) were compared to ten native Korean speakers in their production of seven Korean vowels. The vowel production was used for an identification test by 23 native Korean speaking listeners to further verify the effects of L2 experience on the native Korean listeners’ judgments of Chinese speakers’ vowel production. For the analyses, F1 and F2 values of the initial vowels were measured and normalized across the three groups. The production results showed that the Korean mid vowels /e/ and /Λ/ were produced in a more native-like manner with increased L2 experience. As for the perception results, Chinese speakers’ non-native-like production of Korean vowels /e/ and /Щ/ showed high judgement accuracy, whereas more native-like vowels /u/ and /Λ/ displayed significantly lower accuracy. Overall, the acoustic distinctiveness, rather than native-likeness, of the L2 vowel categories was shown to yield higher accuracy for the perceptual judgments by native listeners. (Konkuk University)

On the role of orthography in L2 vowel production: The case of Polish learners of German

This study investigates the role of orthography in German vowel production by Polish native speakers (L1) with German as a second language (L2). Eighteen intermediate to advanced Polish L2 German learners and 20 German native speakers were recorded during a picture-naming task in which half of the experimental items were explicitly marked in their orthographic representation for their vowel length (short or long). Duration measurements revealed that explicit orthographic marking helped the Polish L2 German learners produce the short-long contrast more native-like. Regarding vowel quality, group differences were interpreted to have been caused by (in)congruencies between L1 and L2 grapheme-to-phoneme correspondences. These findings have important implications for models of L2 speech learning and pronunciation training.

Phonetic interactions in the bilingual production of Galician and Spanish /e/ and /o/

Aims and objectives/purpose/research questions: This study investigates the cross-linguistic phonetic interactions in the production of closed mid vowels of Galician-Spanish bilinguals in a semi-urban area in Galicia. The research questions were: (1) Do Galician-Spanish bilinguals produce /e/ and /o/ similarly in their two languages? (2) Does language dominance influence whether these sounds are produced more like Spanish or more like Galician? (3) Do age and gender influence the bilingual production of Galician and Spanish /e/ and /o/? Design/methodology/approach: Thirty Galician-Spanish bilinguals from the western coast of Galicia completed a sociolinguistic questionnaire and two reading tasks in both Galician and Spanish. Data and analysis: 4,728 vowels were acoustically analyzed and submitted to several mixed effect statistical models. Findings/conclusions: Bilinguals in this study produce distinct phonetic categories for their four Galician mid vowels, and additionally have created new phonetic categories to accommodate their L2 (Spanish) vowels, resulting in a more crowded mid-vowel phonetic space. Originality: This is the first study to examine closed mid vowel realizations in both Spanish and Galician by bilinguals who maintain a Galician four mid-vowel contrast, and to investigate their complex L1-L2 phonetic interactions. Significance/implications: This study offers new data to examine how early bilinguals organize their phonetic system(s) through cross-linguistic assimilation and dissimilation.

Perceptual assimilation of British English vowels to Spanish monophthongs and diphthongs.

This study examined the perceived similarity between Standard British English vowels and Spanish vowels, including Spanish diphthongs, not usually considered in studies on cross-language categorization. Twenty-nine Spanish speakers performed two perceptual assimilation tasks that differed in the number of response alternatives provided, that is, including or excluding diphthongs. The participants also performed an L1 vowel identification task. The results showed that Spanish listeners consistently perceived English diphthongs as closer to Spanish diphthongs than to Spanish monophthongs, with comparatively high assimilation scores. These results emphasize the need to include diphthongs in cross-language comparisons and second-language acquisition studies involving languages like Spanish.

L2의 모음연속체로 지각되는 L1 단모음에 대한 연구

L2의 모음연속체로 지각되는 L1 단모음에 대한 연구

Perception of American-English Vowels by Early and Late Spanish-English Bilinguals.

Increasing numbers of Hispanic immigrants are entering the US and learning American-English (AE) as a second language (L2). Previous studies investigating the relationship between AE and Spanish vowels have revealed an advantage for early L2 learners for their accuracy of L2 vowel perception. Replicating and extending such previous research, this study examined the patterns with which early and late Spanish-English bilingual adults assimilated naturally-produced AE vowels to their native vowel inventory and the accuracy with which they discriminated the vowels. Twelve early Spanish-English bilingual, 12 late Spanish-English bilingual, and 10 monolingual listeners performed perceptual-assimilation and categorical-discrimination tasks involving AE /i,ɪ,ɛ,ʌ,æ,ɑ,o/. Early bilinguals demonstrated similar assimilation patterns to late bilinguals. Late bilinguals' discrimination was less accurate than early bilinguals' and AE monolinguals'. Certain contrasts, such as /æ-ɑ/, /ʌ-ɑ/, and /ʌ-æ/, were particularly difficult to discriminate for both bilingual groups. Consistent with previous research, findings suggest that early L2 learning heightens Spanish-English bilinguals' ability to perceive cross-language phonetic differences. However, even early bilinguals' native-vowel system continues to influence their L2 perception.

Perceptual categorization of English vowels by native European Portuguese speakers

This study reports the results of a perceptual assimilation task (PAT) used to assess the degree of perceived cross-language (dis)similarity between the vowel inventories of European Portuguese (L1) and American English (L2) and, thus, predict difficulty in the perception and production of non-native vowels. Thirty-four native European Portuguese speakers completed a PAT, in which they mapped both L2 English and L1 Portuguese vowels to native vowel categories and rated them for goodness-of-fit to L1 vowels. The results are discussed in terms of theoretical models of cross-language perception and L2 speech learning (SLM, Flege, 1995, & PAM-L2, Best & Tyler, 2007).-----------------------------------------------------------------------------CATEGORIZAÇÃO PERCEPTIVA DE VOGAIS INGLESAS POR FALANTES NATIVOS DE PORTUGUÊS EUROPEUEste estudo reporta os resultados de uma tarefa de assimilação percetiva, usada para avaliar o grau de semelhança inter-linguística entre os inventários vocálicos de português europeu (L1) e de inglês americano (L2), e, assim, prever dificuldades na perceção e produção de sons não nativos. Trinta e quatro falantes nativos de português europeu completaram uma tarefa de assimilação perceptiva, na qual identificaram vogais do inglês (L2) e do português (L1) de acordo com as categorias fonológicas da sua língua nativa, avaliando também a qualidade de representatividade categorial. Os resultados são discutidos partindo de dois modelos de perceção inter-linguística e aprendizagem de fala L2 (SLM, Flege, 1995, & PAM-L2, Best & Tyler, 2007).---Original em inglês.

Improving L2 pronunciation inside and outside the classroom

Spanish/Catalan learners of English as a Foreign Language (EFL) attended a formal instruction (FI) period combined with explicit pronunciation instruction, which consisted of theoretical and practical approaches to English segmental phonetics as well as a contrastive analysis between the participants’ first languages and the target language, English. The EFL learners’ ability to perceive and produce L2 vowels was assessed before and after the 8-week instructional treatment. Results show that the EFL learners significantly improved their perception of vowel sounds embedded in real and non-words. However, no improvement in production was found as a result of the instruction received. While these results suggest that learners’ perceptual skills can be improved with teacher-led instruction, the quantity and availability of explicit pronunciation instruction is not sufficient to modify learners’ speech production. Thus, optimal results require learners to continue learning outside the classroom context. With this aim, this paper presents two autonomous activities developed to increase learners’ awareness about phonology: L1-L2 Pronunciation Comparison Task and a Phonological Self-awareness Questionnaire.

The determining factor of L2 vowel perception: The establishment of L2 categories

The L2 speech learning theories argue that the perception of L2 phonemes is mainly influenced by the relationship between and among L1 and L2 phonemes. In the present study, we hypothesized that L2 vowel identification is primarily determined by the solidity of the L2 vowel category establishment and the perceptual distance between L2 vowel categories. A group of 31 native Mandarin Chinese-speaking listeners and a control group of 9 native English-speaking listeners participated in the study. All listeners were asked to identify natural English/Chinese vowel identification and categorize and rate synthetic English/Chinese vowels. Major findings include: 1) Chinese learners’ English vowel perception was associated with their capacity to establish English vowel category; 2) the perceptual distance between English vowel contrasts played a key role in Chinese learners’ English vowel perception, rather than the distance between the Chinese vowel and English counterpart. Overall, results of this study suggest that the individual variability of Chinese-native listeners’ English vowel perception is interpreted by the establishment of English vowel categories. [Work supported by China Natural Science Foundation 31628009.]

Effects of L2 experience on L2 vowel production and L1 speakers' perception of the improved vowels

Effects of L2 experience on the production of L2 vowels were investigated and the perceptual accuracy of the L2 vowels by native speakers was tested to examine whether an improvement in vowel articulation leads to higher accuracy. A total of twenty Mandarin Chinese differing in the experience (6 months vs. 2 years) were compared to ten native Korean speakers in their production of seven Korean vowels, /i,ɛ,ɨ,ʌ,o,u,a/. More experienced Chinese speakers were expected to have acquired new Korean vowels, /ɛ,ɨ,ʌ,o/, in a more native-like manner than the inexperienced group. The results showed that Chinese learners were able to produce the three similar vowels, /i, u, a/ in a native-like manner even before any exposure to Korean. After 2 years of experience, they have shown to produce the new mid vowels, /ɛ, ʌ/ with greater height distinctions (F1 values) from adjacent high vowels. Although the two high back vowels, /o, u/ were deviant from the native norm, the Experienced group learned to distinguish the vowels with a distinctive F2 frequency, which has become a critical cue for the distinction of the two merging vowels by young Seoul speakers. When native Korean speakers were asked to identify the vowels produced by Chinese speakers, not only new mid vowels but also similar vowels were more accurately identified for the experienced group. The greatest improvement in perceptual accuracy was shown for the categories that were newly established by the inexperienced learners.

The effect of native language on the second language vowel variability

Korean learners of English must create four vowel categories for English (/i, ɪ/ and /ɛ, ae/) in relation to two similar native categories (/i/ and /ɛ/). It is hypothesized that new categories should be easier to learn than similar ones (Flege, 1994), but it is unclear whether the English L2 vowels are similar or new. The degree of similarity between the four English vowels and the two Korean vowels was examined using the distribution metrics (i.e., ellipse overlap, cross-entropy, and Gaussian Mixture Model) as well as Euclidean distance in F1/F2 space. The L2 spoken corpus included 100 repetitions of words in both Korean and English spoken by 37 Korean L2 learners (20 female). Preliminary results indicate that the English (L2) high vowel pair was more overlapped with Korean /i/ than the low vowel pair with Korean /ɛ/, especially for male speakers. For the English (L2) low vowel pair, female speakers showed less overlap but higher variability along F1 direction than male speakers. This demonstrates that the similarity between Korean and English vowels is characterized by the distribution as well as the distances between the vowel categories. Acoustic results will be further compared with identification by native English speakers.

L1 Korean vocalic transfer in adult L2 Korean learners\u2019 production of Vietnamese monophthong vowels

This paper reports a study that investigated the role of prior native or first language (L1) phonological and phonetic learning on the integration of vowel quality features in the production of second language (L2) vowels by examining adult L2 Korean learners’ production of Vietnamese monophthong vowels in an imitation and a read aloud tasks. Three groups of participants took part in the study (11 control Vietnamese, 11 Korean learners of Vietnamese, and 10 control Korean). The stimuli consisted of 9 Vietnamese monophthongs /i, e, ɛ, a, ɔ, o, u, ɤ, ɯ/ and 8 Standard Korean vowels / i, ɛ, e, a, o, u, ʌ, ɨ /. The results showed that Vietnamese vowels /ɛ/ and /e/ produced by Korean learners merged in vowel space, proving how a phonemic merger in L1 can influence speakers’ perception and production of non-native vowels. Moreover, the three Vietnamese vowels /ɔ/, /o/ and/ ɤ/ produced by Korean learners in both tasks tend to cluster together. In general, the findings of this study showed that Korean learners transfer their L1 vowel quality features into the production of Vietnamese vowels.

Percepção da vogal /a/ do espanhol, em contextos nasais, por brasileiros

Este estudo propõe-se investigar a percepção da vogal /a/ do espanhol, em contextos nasais, por falantes nativos de português brasileiro (PB), estudantes do Curso de Licenciatura em Letras Português-Espanhol de uma universidade do sul do Brasil. Considerando que, no PB, a nasalização fonética é recorrente e atinge mais contextos do que no espanhol, buscamos verificar se os estudantes conseguem perceber quando a vogal /a/ no espanhol é produzida como oral ou nasal, ou se, por influência do português, têm a percepção de nasalidade mesmo em contextos não nasalizados, segundo a literatura, no espanhol. O corpus para a realização da pesquisa foi constituído de uma amostra de quinze estudantes do primeiro semestre do Curso de Letras, com idade entre 18 e 49 anos. Os estudantes foram submetidos a quatro testes de percepção – três de discriminação e um de identificação –, que foram criados no software TP, especificamente para o presente estudo. A análise do processo de percepção da vogal /a/, em contextos nasais, foi feita com base nos pressupostos do Modelo de Aprendizagem de fala (SLM), incluindo também tratamento estatístico dos resultados. Os dados apontaram melhores resultados nos testes de discriminação do que no teste de identificação, o que foi atribuído ao tipo de processamento por cada um exigido, e a dificuldade de percepção da vogal nasalizada no espanhol foi entendida como decorrente da proximidade fonética entre a L1 e a L2, fazendo resultar a percepção de uma categoria já existente na sua L1, especialmente por ser alofônica a nasalidade vocálica na L2.