Vowel reduction in word-final position by early and late Spanish-English bilinguals

Abstract

Vowel reduction is a prominent feature of American English, as well as other stress-timed languages. As a phonological process, vowel reduction neutralizes multiple vowel quality contrasts in unstressed syllables. For bilinguals whose native language is not characterized by large spectral and durational differences between tonic and atonic vowels, systematically reducing unstressed vowels to the central vowel space can be problematic. Failure to maintain this pattern of stressed-unstressed syllables in American English is one key element that contributes to a “foreign accent” in second language speakers. Reduced vowels, or “schwas,” have also been identified as particularly vulnerable to the co-articulatory effects of adjacent consonants. The current study examined the effects of adjacent sounds on the spectral and temporal qualities of schwa in word-final position. Three groups of English-speaking adults were tested: Miami-based monolingual English speakers, early Spanish-English bilinguals, and late Spanish-English bilinguals. Subjects performed a reading task to examine their schwa productions in fluent speech when schwas were preceded by consonants from various points of articulation. Results indicated that monolingual English and late Spanish-English bilingual groups produced targeted vowel qualities for schwa, whereas early Spanish-English bilinguals lacked homogeneity in their vowel productions. This extends prior claims that schwa is targetless for F2 position for native speakers to highly-proficient bilingual speakers. Though spectral qualities lacked homogeneity for early Spanish-English bilinguals, early bilinguals produced schwas with near native-like vowel duration. In contrast, late bilinguals produced schwas with significantly longer durations than English monolinguals or early Spanish-English bilinguals. Our results suggest that the temporal properties of a language are better integrated into second language phonologies than spectral qualities. Finally, we examined the role of nonstructural variables (e.g. linguistic history measures) in predicting native-like vowel duration. These factors included: Age of L2 learning, amount of L1 use, and self-reported bilingual dominance. Our results suggested that different sociolinguistic factors predicted native-like reduced vowel duration than predicted native-like vowel qualities across multiple phonetic environments.

Stress-Induced Acoustic Variation in L2 and L1 Spanish Vowels

“…Perhaps the failure of these intermediate L2 learners to shorten unstressed Spanish vowels as much as unstressed English ones could be attributed to their having already acquired the L2 durational features, even though their spectral features were not native-like. A similar finding is reported by Byers and Yavas (2017) for the acquisition of English /ə/ by early and late Spanish L1, English L2 bilinguals, although the early bilinguals were more native-like than the late bilinguals. They state that their findings suggest that "temporal properties of a language are better integrated into second language phonologies than spectral qualities" (p. 1), and our results provide independent support for this view.…”

Polysyllabic shortening in Spanish-English bilingual children

“…Reduced vowels are produced with shorter duration than their full vowel counterparts. English makes frequent use of vowel reduction, thus creating variation in syllable length, but recent studies by Byers and Yavas (2016, 2017) have demonstrated that this phenomenon does not occur in Spanish. This can be interpreted as yet another phenomenon that yields greater variation in syllable duration in English compared to Spanish.…”

A Pronunciation Prior Assisted Vowel Reduction Detection Framework with Multi-Stream Attention Method

“…In previous studies, acoustic characteristics of vowel reduction are concerned [7][8][9][10][11]. However, few studies have contributed to the area of automatically detecting vowel reduction.…”