Non-native Vowel Research Articles

Learning unfamiliar words and perceiving non-native vowels in a second language: Insights from eye tracking

One of the challenges in second-language learning is learning unfamiliar word forms, especially when this involves novel phoneme contrasts. The present study examines how real-time processing of newly-learned words and phonemes in a second language is impacted by the structure of learning (discrimination training) and whether asking participants to complete the same task after a 16–21 h delay favours subsequent word recognition. Specifically, using a visual world eye tracking paradigm, we assessed how English listeners processed newly-learned words containing non-native French front-rounded [y] compared to native-sounding vowels, both immediately after training and the following day. Some learners were forced to discriminate between vowels that are perceptually similar for English listeners, [y]-[u], while others were not. We found significantly better word-level processing on a variety of indices after an overnight delay. We also found that training [y] words paired with [u] words (vs. [y]-Control pairs) led to a greater decrease in reaction times during the word recognition task over the two testing sessions. Discrimination training using perceptually similar sounds had facilitative effects on second language word learning with novel phonemic information, and real-time processing measures such as eyetracking provided valuable insights into how individuals learn words and phonemes in a second language.

Listen-and-repeat training in the learning of non-native consonant duration contrasts: influence of consonant type as reflected by MMN and behavioral methods

Phonological duration differences in quantity languages can be problematic for second language learners whose native language does not use duration contrastively. Recent studies have found improvement in the processing of non-native vowel duration contrasts with the use of listen-and-repeat training, and the current study explores the efficacy of similar methodology on consonant duration contrasts. 18 adult participants underwent two days of listen-and-repeat training with pseudoword stimuli containing either a sibilant or a stop consonant contrast. The results were examined with psychophysiological event-related potentials (mismatch negativity and P3), behavioral discrimination tests and a production task. The results revealed no training-related effects in the event-related potentials or the production task, but behavioral discrimination performance improved. Furthermore, differences emerged between the processing of the two consonant types. The findings suggest that stop consonants are processed more slowly than the sibilants, and the findings are discussed with regard to possible segmentation difficulties.

Phonetic listen-and-repeat training alters 6–7-year-old children’s non-native vowel contrast production after one training session

Abstract The present study investigated children’s ability to learn to produce a non-native vowel contrast through a listen-and-repeat training method that is traditionally used in foreign language classrooms. Sixteen Finnish preschoolers (aged 6–7 years) were tested. The stimuli were two semi-synthetic pseudo words with the familiar vowel /y/ and the novel vowel /ʉ/ embedded in the first syllable. The procedure included four training and four recording sessions on two consecutive days. The vowels produced by the children were acoustically analyzed to obtain the average values of the first and second formant. The results showed that the participants changed their production of /ʉ/ towards the acoustic model after the first training and the change remained throughout the experiment. Our findings suggest 6–7-year-old children learn to produce a non-native vowel contrast even with limited L2 sound exposure in a listen-and-repeat training setting.

Does Studying in a Music-oriented Education Program Affect Non-native Sound Learning? — Effects of Passive Auditory Training on Children’s Vowel Production

Earlier studies have shown that children are efficient second language learners. Research has also shown that musical background might affect second language learning. A two-day auditory training paradigm was used to investigate whether studying in a music-oriented education program affects children’s sensitivity to acquire a non-native vowel contrast. Training effects were measured with listen-and-repeat production tests. Two groups of monolingual Finnish children (9–11 years, N=23) attending music-oriented and regular fourth grades were tested. The stimuli were two semisynthetic pseudo words /ty:ti/ and /tʉ:ti/ with the native vowel /y/ and the non-native vowel /ʉ/ embedded. Both groups changed their pronunciation after the first training. The change was reflected in the second formant values of /ʉ/, which lowered significantly after three trainings. The results show that 9–11-year-old children benefit from passive auditory training in second language production learning regardless of whether or not they attend a music-oriented education program.

Language Experience and Subjective Word Familiarity on the Multimodal Perception of Non-native Vowels.

The present study investigated native (L1) and non-native (L2) speakers' perception of the French vowels /ɔ̃, ɑ̃, ɛ̃, o/. Thirty-four American-English learners of French and 33 native speakers of Parisian French were asked to identify 60 monosyllabic words produced by a native speaker in three modalities of presentation: auditory-only (A-only); audiovisual (AV); and visual-only (V-only). The L2 participants also completed a vocabulary knowledge test of the words presented in the perception experiment that aimed to explore whether subjective word familiarity affected speech perception. Results showed that overall performance was better in the AV and A-only conditions for the two groups with the pattern of confusion differing across modalities. The lack of audiovisual benefit was not due to the vowel contrasts being not visually salient enough, as shown by the native group's performance in the V-only modality, but to the L2 group's weaker sensitivity to visual information. Additionally, a significant relationship was found between subjective word familiarity and AV and A-only (but not V-only) perception of non-native contrasts.

Training non-native vowel perception: In quiet or noise.

Noise makes speech perception much more challenging for non-native listeners than for native listeners. Training for non-native speech perception is usually implemented in quiet. It remains unclear if background noise may benefit or hamper non-native speech perception learning. In this study, 51 Chinese-native listeners were randomly assigned into three groups, including vowel training in quiet (TIQ), vowel training in noise (TIN), and watching videos in English as an active control. Vowel identification was assessed before (T1), right after (T2), and three months after training (T3) in quiet and various noise conditions. Results indicated that compared with the video watching group, the TIN group improved vowel identification in both quiet and noise significantly more at T2 and at T3. In contrast, the TIQ group improved significantly more in quiet and also in non-speech noise conditions at T2, but the improvement did not hold at T3. Moreover, compared to the TIQ group, the TIN group showed significantly less informational masking at both T2 and T3 and less energetic masking at T3. These results suggest that L2 speech training in background noise may improve non-native vowel perception more effectively than TIQ background only. The implications for non-native speech perception learning are discussed.

The Effects of Language Contact on Non-Native Vowel Sequences in Lexical Borrowings: The Case of Media Lengua.

Media Lengua (ML), a mixed language derived from Quichua and Spanish, exhibits a phonological system that largely conforms to that of Quichua acoustically. Yet, it incorporates a large number of vowel sequences from Spanish which do not occur in the Quichua system. This includes the use of mid-vowels, which are phonetically realized in ML as largely overlapping with the high-vowels in acoustic space. We analyze and compare production of vowel sequences by speakers of ML, Quichua, and Spanish through the use of generalized additive mixed models to determine statistically significant differences between vowel formant trajectories. Our results indicate that Spanish-derived ML vowel sequences frequently differ significantly from their Spanish counterparts, largely occupying a more central region of the vowel space and frequently exhibiting markedly reduced trajectories over time. In contrast, we find only one case where an ML vowel sequence differs significantly from its Quichua counterpart-and even in this case the difference from Spanish is substantially greater. Our findings show how the vowel system of ML successfully integrates novel vowel sequence patterns from Spanish into what is essentially Quichua phonology by markedly adapting their production, while still maintaining contrasts which are not expressed in Quichua.

Perception of English and Catalan vowels by English and Catalan listeners: A study of reciprocal cross-linguistic similarity.

This study reports the results of two experiments aimed at assessing the perceived similarity between English and Catalan vowels and diphthongs. Perceived similarity judgements were elicited from speakers of both languages involved and were compared to first language identification data from the same speakers. In experiment 1, a group of 27 naive Catalan listeners performed a perceptual assimilation task in which they were asked to identify Catalan and English vowels in terms of native categories and provide a goodness of fit rating. In experiment 2, a group of native speakers of Southern British English performed an adaptation of the same task. The results showed that most non-native vowels were consistently perceived as instances of a given native category, with varying degrees of goodness of fit. In a few cases, assimilation scores were very high in both experiments, pointing to the possibility of near-identical or shared categories. A few asymmetrical mappings were found, which were linked to the influence of language-specific cues such as the role of vowel duration in English. These results emphasize the importance of contrasting native and non-native perception and the potential of reciprocal approaches for making predictions about non-native perception and second language development.

Acoustic salience in the evaluations of intelligibility and foreign accentedness of nonnative vowel production

The study investigates the relative weighting of spectral and temporal acoustic cues in native speakers’ (NS) perception of vowels produced by nonnative speakers (NNS). Acoustic measurements were taken of the spectral and temporal properties of vowels produced by Chinese L2 speakers of English, and by native speakers of American English and British English, who were recruited to pronounce monosyllabic words containing 18 monophthongs and diphthongs in English. In the perception experiment, 25 native English speakers (16 American and 9 British) provided evaluations of intelligibility and ratings of foreign accentedness of the non-native vowels. A correlation analysis was conducted between the NS perception results and the acoustic computation of the NNS production data. The results show that spectral properties of vowels are significantly related to both American and British speakers’ evaluation of English vowels produced by Chinese L2 speakers, whereas the temporal information has no significant correlation to NS perceptual evaluations. The correlation between acoustic measurements and perceptual evaluations confirms that the most significant acoustic cue of English vowels is spectral rather than temporal information in perception.

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.

Sing for me, Mama! Infants' discrimination of novel vowels in song.

When adults speak or sing with infants, they sound differently than in adult communication. Infant-directed (ID) communication helps caregivers to regulate infants' emotions and helps infants to process speech information, at least from ID-speech. However, it is largely unclear whether infants might also process speech information presented in ID-singing. Therefore, we examined whether infants discriminate vowels in ID-singing, as well as potential differences with ID-speech. Using an alternating trial preference procedure, infants aged 4-6 and 8-10months were tested on their discrimination of an unfamiliar non-native vowel contrast presented in ID-like speech and singing. Relying on models of early speech sound perception, we expected that infants in their first half year of life would discriminate the vowels, in contrast to older infants whose non-native sound perception should deteriorate, at least in ID-like speech. Our results showed that infants of both age groups were able to discriminate the vowels in ID-like singing, while only the younger group discriminated the vowels in ID-like speech. These results show that infants process speech sound information in song from early on. They also hint at diverging perceptual or attentional mechanisms guiding infants' sound processing in ID-speech versus ID-singing toward the end of the first year of life.

Effects of high variability phonetic training on cue reweighting in non-native vowel perception by adult Chinese learners

While native English speakers have been found to primarily use vowel spectrum on /i/-/ɪ/ perception, Chinese learners of English dominantly use vowel duration. This study examined training effects on cue reweighting in perceiving /i/-/ɪ/ by Chinese learners. We modified the canonical HVPT paradigm with introducing variability along the secondary dimension for the contrast distinction (i.e., duration). Forty native Chinese-speaking adults were randomly assigned to two groups: the training group and the control group. Pre- and post- training tests used the tasks of natural word identification and synthetic phoneme identification. Synthesized phoneme stimuli were the two-dimensional (spectrum and duration) stimulus continua ranging from English /i/ to /ɪ/, and the natural word stimuli included both trained and untrained words produced by novel talkers. The results demonstrated that the training group showed more reliance on the primary spectral cue and less reliance on the secondary durational cue after training. The corroborating data from the word identification showed the training group improved significantly and generalized learning to new talkers and phonetic contexts. The control group did not show similar changes. These results indicated that high variability phonetic training is effective on helping L2 learners to retune attention to primary cues which facilitate generalization outcomes.

Real-time visual acoustic feedback for non-native vowel production training

Computer-Assisted Pronunciation Training (CAPT) software which include visual feedback have shown potential for second language (L2) learning (Mehta & Katz, 2018). However, real-time formant visualization has yet to be used for L2 learners' production of speech sounds. This project investigates the effects of real-time formant visualization on L2 vowel production training. First, a vowel visualization system is presented. In contrast with other similar tools which use a regression approach (Frostel et al., 2011), this real-time formant (F1 and F2) extraction is performed using the Parselmouth library (Jadoul et al., 2018), which then uses Praat's formant extraction algorithm (Gray & Wong, 1980) to ensure accuracy. Then, the results from a preliminary user study are reported. L2 learners (n = 5) participated in six 30-min training sessions, during which they used the system to practice their production of eight vowels. Pronunciation accuracy was analyzed by calculating Mahalanobis distances between participants' productions (produced in pre-test and post-test) and native exemplars. The analysis of this preliminary dataset showed that the use of real-time visual acoustic feedback resulted in L2 vowel production improvement, which suggests that this system could, therefore, be used as a pedagogical tool for L2 learners.

Training a non-native vowel contrast with a distributional learning paradigm results in improved perception and production

Previous distributional learning research suggests that adults can improve perception of a non-native contrast more efficiently when exposed to a bimodal than a unimodal distribution. Studies have also suggested that perceptual learning can transfer to production. The current study tested whether the addition of visual images to reinforce the contrast and active learning with feedback would result in learning in both conditions and would transfer to gains in production. Native English-speaking adults heard stimuli from a bimodal or unimodal /o/-/œ/ continuum. No group differences were found on a discrimination task, possibly suggesting that the supports eliminated previously documented group differences. On an identification task, listeners in the bimodal group showed better performance than the unimodal group on the endpoint stimuli. Production results indicated that both groups showed increased Euclidean distance between the target vowels after training, suggesting that perceptual training improved production skills in both conditions. Contrary to expectations, degree of perception and production learning were not correlated. Together, these results suggest that a bimodal distribution may aid learning, but that adding images to reinforce the contrast and active learning to the training paradigm could mitigate disadvantages found previously for participants exposed to a unimodal distribution.

The role of auditory feedback in learning speech of second languages

Learning to speak requires coordination between auditory and motor systems. Motor programs need to be fine-tuned based on goals and feedback. The motor-tuning process includes establishing the sensory-to-motor transformation (generate motor codes from articulation) and motor-to-sensory transformation (generate predictions for speech control). In this study, we investigated the relations among the three factors (feedback, goals, and predictions) in speech production in the context of second language learning. Adult Mandarin speakers were asked to learn non-native vowels: /o/ and /ɵ/—the former being less similar than the latter to Mandarin vowels, in feedback available or feedback masked conditions. We found no improvement in learning when feedback was masked, suggesting that motor-based prediction could not directly compare with goals for adult second language acquisition. Furthermore, feedback helped to learn only when target sounds are distinct from existing sounds in one’s native speech (competition between prediction and goals is minimal). The results suggest prediction and goals may share a similar representational format, which could yield a competing relation in speech learning. The feedback can conditionally overcome such interference between prediction and goals. The study further probed the functional relations among key components (prediction, goals, and feedback) of sensorimotor integration in speech production and learning.Learning to speak requires coordination between auditory and motor systems. Motor programs need to be fine-tuned based on goals and feedback. The motor-tuning process includes establishing the sensory-to-motor transformation (generate motor codes from articulation) and motor-to-sensory transformation (generate predictions for speech control). In this study, we investigated the relations among the three factors (feedback, goals, and predictions) in speech production in the context of second language learning. Adult Mandarin speakers were asked to learn non-native vowels: /o/ and /ɵ/—the former being less similar than the latter to Mandarin vowels, in feedback available or feedback masked conditions. We found no improvement in learning when feedback was masked, suggesting that motor-based prediction could not directly compare with goals for adult second language acquisition. Furthermore, feedback helped to learn only when target sounds are distinct from existing sounds in one’s native speech (competition be...

Interplay of native and non-native vowels in Japanese late learners of English

Interplay of native and non-native vowels in Japanese late learners of English

Arabic-speakers Learning Finnish Vowels: Short-term Phonetic Training Supports Second Language Vowel Production

Considering all the many challenges of forced migration to the immigrants themselves, learning the local language is of extreme importance when attempting to integrate into a new society. Earlier research shows that the mother tongue phonology disturbs the perception of those redundant contrasts that are crucial to the target language, which then affects the production of the second language. The main purpose of this study was to see whether Arabic speakers learn to produce universally difficult non-native vowel sounds with only a short and simple articulatory training protocol. Thirteen Arabic speaking asylum seekers were tested and trained with natural stimuli produced by four speakers. The vowels /y/ and /ø/ were embedded in pseudowords /ty:ti/ and /tø:ti/. The first three formants of both pre- and post-test productions were analyzed, and the results of both acoustic and statistical analyses showed that there was a significant change in the production of both vowels. This implies that even a short-term phonetic training improves the production of the target language, which is worth noting as an enabler of the language learning process that immigrants undergo during their journey towards cultural integration.

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.

Comparing acoustic and articulatory targets in short-term visual feedback training of non-native vowels

Theories of speech production aim to explain how talkers express abstract linguistic forms as audible events that are intelligible to both speaker and listener. The relationship among planned units of speech, their articulatory implementation, and their acoustic consequences is thus a key issue in speech research. The work reported here is part of a larger project designed to investigate the effects of visual acoustic and visual articulatory feedback on second language (L2) learners’ production and perception of non-native speech sounds. L2 talkers from a variety of language backgrounds practiced producing an English vowel, /æ/, while receiving visual feedback on either (1) first and second formant frequencies, provided by a real-time spectrographic display, or (2) tongue back position, shown using a talker-driven tongue avatar. Kinematic data were recorded using an electromagnetic articulograph (EMA) system that tracked tongue midline and lateral movement during vowel productions. Pronunciation accuracy was analyzed by calculating acoustic and kinematic Mahalanobis distances between L2 productions and target (native talker) exemplars. Initial analyses of a single subject’s data showed that both types of visual feedback training improved pronunciation, suggesting that both acoustic and articulatory information are recruited during vowel production.

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.