UCLA

Second language (L2) learners often struggle with achieving native-like production and perception of L2 sounds. While there is ample research on the non-native perception of English vowels by native speakers of languages with smaller vowel inventories, scant research exists up-to-date on the opposite scenario. The aim of the present study is to investigate the initial state for Californian English (CE) listeners' perception of two different smaller vowel inventories, namely Spanish and Portuguese vowels, before any perceptual learning has taken place. The objective is to determine how CE listeners' native vowel inventory of (at least) ten phonemes affects their non-native perception of the five Spanish and seven Portuguese vowel phonemes.

Monolingual speakers of English from Southern California (N = 18) completed a perceptual assimilation task, in which they labeled naturally produced tokens of Spanish and Portuguese vowels in terms of ten native English categories, as well as a categorial discrimination task with four Spanish and six Portuguese vowel contrasts. In the perceptual assimilation task, CE listeners mapped almost every Spanish and Portuguese vowel contrast to more than two native categories, resulting in many instances of Multiple Category Assimilation (MCA, Escudero and Boersma, 2002). Furthermore, some phonologically common vowels between Spanish and Portuguese, namely /e/, /o/, and /a/, were mapped differently to English categories, suggesting that cross-linguistic differences in the acoustic distributions of these sounds result in differences in their categorization by non-native listeners.

In the discrimination task, CE listeners were highly accurate at distinguishing all Spanish vowel contrasts but were less accurate on three Portuguese vowel contrasts, /i-e/, /o-u/, and /a-O/. Crucially, MCA was found to be responsible for listeners' lower discrimination accuracy only when it contributed to two vowels being perceptually assimilated to an overlapping set of native categories, i.e., when two different vowels had a high perceptual assimilation overlap score. The results are examined vis-à-vis two main models of second language speech perception, the Perceptual Assimilation Model (PAM, Best, 1995) and the Second Language Linguistic Perception Model (L2LP, Escudero, 2005). Implications for L2 acquisition of Spanish and Portuguese vowels by English-speaking learners are discussed.