Influences of listeners' native and other dialects on cross-language vowel perception

Australian English listeners' perception of Japanese vowel length reveals underlying phonological knowledge

Speech perception patterns are strongly influenced by one's native phonology. It is generally accepted that native English listeners rely primarily on spectral cues when perceiving vowels, making limited use of duration cues because English lacks phonemic vowel length. However, the literature on vowel perception by English listeners shows a marked bias toward American English, with the phonological diversity among different varieties of English largely overlooked. The current study investigates the perception of Japanese vowel length contrasts by native listeners of Australian English, which is reported to use length to distinguish vowels unlike most other varieties of English. Twenty monolingual Australian English listeners participated in a forced-choice experiment, where they categorized Japanese long and short vowels as most similar to their native vowel categories. The results showed a general tendency for Japanese long and short vowels (e.g., /ii, i/) to be categorized as Australian English long and short vowels (e.g., /i:, ɪ/ as in "heed," "hid"), respectively, which contrasts with American English listeners' categorization of all Japanese vowels as tense regardless of length (e.g., /ii, i/ as both "heed") as reported previously. Moreover, this duration-based categorization was found not only for Australian English categories that contrast in duration alone (e.g., /ɐ:, ɐ/ as in "hard," "hud") but also for those that contrast in both duration and spectra (e.g., /o:, ɔ/ as in "hoard," "hod"), despite their spectral mismatch from the corresponding Japanese vowels (e.g., /aa, a/ and /oo, o/). The results, therefore, suggest that duration cues play a prominent role across all vowel categories-even nonnative-for Australian English listeners. The finding supports a feature-based framework of speech perception, where phonological features like length are shared across multiple categories, rather than the segment-based framework that is currently dominant, which regards acoustic cues like duration as being tied to a specific native segmental category. Implications for second and foreign language learning are discussed.

Perceptuomotor compatibility effects in vowels: Effects of consonantal context and acoustic proximity of response and distractor

In a cue-distractor task, speakers' response times (RTs) were found to speed up when they perceived a distractor syllable whose vowel was identical to the vowel in the syllable they were preparing to utter. At a more fine-grained level, subphonemic congruency between response and distractor-defined by higher number of shared phonological features or higher acoustic proximity-was also found to be predictive of RT modulations. Furthermore, the findings indicate that perception of vowel stimuli embedded in syllables gives rise to robust and more consistent perceptuomotor compatibility effects (compared to isolated vowels) across different response-distractor vowel pairs.

English only? Monolinguals in linguistically diverse contexts have an edge in language learning

Accumulating evidence shows how language context shapes bilingual language use and its cognitive consequences. However, few studies have considered the impact of language context for monolinguals. Although monolinguals' language processing is assumed to be relatively stable and homogeneous, some research has shown novel learning through exposure alone. Monolinguals living in linguistically diverse contexts regularly overhear languages they do not understand, and may absorb information about those languages in ways that shape their language networks. The current study used behavioral and ERP measures to compare monolinguals living in a linguistically diverse environment and a unilingual environment in their ability to learn vowel harmony in Finnish. Monolinguals in both contexts demonstrated similar learning of studied words; however, their ERPs differed for generalization. Monolinguals in the diverse context revealed an anterior late positivity, whereas monolinguals in the unilingual context showed no effect. The results suggest that linguistic diversity promotes new language learning.

Spanish is better than English for discriminating Portuguese vowels: acoustic similarity versus vowel inventory size

Second language (L2) learners often struggle to distinguish sound contrasts that are not present in their native language (L1). Models of non-native and L2 sound perception claim that perceptual similarity between L1 and L2 sound contrasts correctly predicts discrimination by naïve listeners and L2 learners. The present study tested the explanatory power of vowel inventory size versus acoustic properties as predictors of discrimination accuracy when naïve Australian English (AusE) and Iberian Spanish (IS) listeners are presented with six Brazilian Portuguese (BP) vowel contrasts. Our results show that IS listeners outperformed AusE listeners, confirming that cross-linguistic acoustic properties, rather than cross-linguistic vowel inventory sizes, successfully predict non-native discrimination difficulty. Furthermore, acoustic distance between BP vowels and closest L1 vowels successfully predicted differential levels of difficulty among the six BP contrasts, with BP /e-i/ and /o-u/ being the most difficult for both listener groups. We discuss the importance of our findings for the adequacy of models of L2 speech perception.