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

Perception of second language phonetic contrasts by monolinguals and bidialectals: A comparison of competencies

This study aims to examine the perception of English vowels by Greek monolingual and bidialectal speakers of English as a second language (L2) and assess the predictions of the Universal Perceptual Model (UPM). Adult Cypriot Greek (CG) bidialectal speakers and Standard Modern Greek (SMG) monolingual speakers participated in classification and discrimination tests. The two groups were matched for various linguistic, sociolinguistic, and cognitive factors. Another group of adult English speakers served as controls. Data analysis has been conducted with the use of Bayesian regression models. The results of the discrimination test were predicted by acoustic similarity only to some extent, whereas perceptual similarity predicted most contrasts, confirming the hypotheses of UPM. A crucial finding was that bidialectals outperformed monolinguals in the discrimination of L2 contrasts. The advantage observed in bidialectals could be attributed to the greater flexibility of their speech categories, stemming from exposure to more diverse linguistic input.

Perception of Dutch vowels by Cypriot Greek listeners: To what extent can listeners' patterns be predicted by acoustic and perceptual similarity?

There have been numerous studies investigating the perception of non-native sounds by listeners with different first language (L1) backgrounds. However, research needs to expand to under-researched languages and incorporate predictions conducted under the assumptions of new speech models. This study aimed to investigate the perception of Dutch vowels by Cypriot Greek adult listeners and test the predictions of cross-linguistic acoustic and perceptual similarity. The predictions of acoustic similarity were formed using a machine-learning algorithm. Listeners completed a classification test, which served as the baseline for developing the predictions of perceptual similarity by employing the framework of the Universal Perceptual Model (UPM), and an AXB discrimination test; the latter allowed the evaluation of both acoustic and perceptual predictions. The findings indicated that listeners classified each non-native vowel as one or more L1 vowels, while the discrimination accuracy over the non-native contrasts was moderate. In addition, cross-linguistic acoustic similarity predicted to a large extent the classification of non-native sounds in terms of L1 categories and both the acoustic and perceptual similarity predicted the discrimination accuracy of all contrasts. Being in line with prior findings, these findings demonstrate that acoustic and perceptual cues are reliable predictors of non-native contrast discrimination and that the UPM model can make accurate estimations for the discrimination patterns of non-native listeners.

Comparison of the prediction accuracy of machine learning algorithms in crosslinguistic vowel classification

Machine learning algorithms can be used for the prediction of nonnative sound classification based on crosslinguistic acoustic similarity. To date, very few linguistic studies have compared the classification accuracy of different algorithms. This study aims to assess how well machines align with human speech perception by assessing the ability of three machine learning algorithms, namely, linear discriminant analysis (LDA), decision tree (C5.0), and neural network (NNET), to predict the classification of second language (L2) sounds in terms of first language (L1) categories. The models were trained using the first three formants and duration of L1 vowels and fed with the same acoustic features of L2 vowels. To validate their accuracy, adult L2 speakers completed a perceptual classification task. The results indicated that NNET predicted with success the classification of all L2 vowels with the highest proportion in terms of L1 categories, while LDA and C5.0 missed only one vowel each. Furthermore, NNET exhibited superior accuracy in predicting the full range of above chance responses, followed closely by LDA. C5.0 did not meet the anticipated performance levels. The findings can hold significant implications for advancing both the theoretical and practical frameworks of speech acquisition.

Development of perceptual similarity and discriminability: the perception of Russian phonemes by Chinese learners

This study explored the perceptual assimilation and discrimination of Russian phonemes by three groups of Chinese listeners with differing Russian learning experience. A perceptual assimilation task (PAT) and a perceptual discrimination test (PDT) were conducted to investigate if/how L1-L2 perceptual similarity would vary as a function of increased learning experience, and the development of assimilation-discrimination relations. The PAT was analyzed via assimilation rates, dispersion K' values, goodness ratings and assimilation patterns. Results revealed an intriguing phenomenon that the perceived Mandarin-Russian similarity first increased from naïve listeners to intermediate learners and then decreased slightly in relatively advanced learners. This suggests that L1-L2 perceptual similarity is subject to learning experience and could follow a potential "rise and fall" developmental pattern. The PDT results were mostly in line with the assimilation-discrimination correspondence with more experience bringing out better discriminability in general. Yet the overall sensitivity d' values from the Chinese groups were relatively low, implying acoustic/articulatory effects on L2 discriminability aside from perceptual assimilation. The results were discussed under the frameworks of L2 Perceptual Assimilation Model, Speech Learning Model and L2 Linguistic Perception Model.

The Acquisition of /ɪ/-/iː/ Is Challenging: Perceptual and Production Evidence from Cypriot Greek Speakers of English

This study aims to investigate the perception and production of the English /ɪ/-/iː/ vowel contrast by Cypriot Greek speakers of English as a second language (L2). The participants completed a classification test in which they classified the L2 vowels in terms of their first language (L1) categories, a discrimination test in which they distinguished the members of the vowel contrast, and a production test in which they produced the target vowels. The results showed that they classified both L2 /ɪ/-/iː/ mostly in terms of L1 /i/, which denotes the formation of a completely overlapping contrast according to the theoretical framework of the Universal Perceptual Model (UPM), and that they could hardly distinguish the vowel pair. In addition, their productions deviated in most acoustic parameters from the corresponding productions of English controls. The findings suggest that /ɪ/-/iː/ may carry a universal marker of difficulty for speakers with L1s that do not possess this contrast. This distinction is difficult even for experienced L2 speakers probably because they had never been exposed to naturalistic L2 stimuli and they do not use the L2 that much in their daily life. Finally, the study verifies UPM's predictions about the discriminability of the contrast and extends the model's implications to speech production; when an L2 vowel contrast is perceived as completely overlapping, speakers activate a (near-) unified interlinguistic exemplar in their vowel space, which represents both L2 vowels.

Music Perception Abilities and Ambiguous Word Learning: Is There Cross-Domain Transfer in Nonmusicians?

Perception of music and speech is based on similar auditory skills, and it is often suggested that those with enhanced music perception skills may perceive and learn novel words more easily. The current study tested whether music perception abilities are associated with novel word learning in an ambiguous learning scenario. Using a cross-situational word learning (CSWL) task, nonmusician adults were exposed to word-object pairings between eight novel words and visual referents. Novel words were either non-minimal pairs differing in all sounds or minimal pairs differing in their initial consonant or vowel. In order to be successful in this task, learners need to be able to correctly encode the phonological details of the novel words and have sufficient auditory working memory to remember the correct word-object pairings. Using the Mistuning Perception Test (MPT) and the Melodic Discrimination Test (MDT), we measured learners’ pitch perception and auditory working memory. We predicted that those with higher MPT and MDT values would perform better in the CSWL task and in particular for novel words with high phonological overlap (i.e., minimal pairs). We found that higher musical perception skills led to higher accuracy for non-minimal pairs and minimal pairs differing in their initial consonant. Interestingly, this was not the case for vowel minimal pairs. We discuss the results in relation to theories of second language word learning such as the Second Language Perception model (L2LP).