Difficulty in discriminating non-native vowels : are Dutch vowels easier for Australian English than Spanish listeners?

Previous studies have shown that the number of vowels present in one's L1 inventory may affect the ability to learn and discriminate non-native vowel contrasts. Specifically, learners whose L1 contains fewer vowels compared to the target language may find many non-native vowel contrasts novel and have discrimination performance lower than learners whose L1 contains more vowels than the target language for whom most of the non-native vowel contrasts will be familiar. The present study tested monolingual Australian English (AusE) listeners' discrimination of non-native vowels in Dutch, which has fewer vowels compared to AusE. We further compared AusE listeners' performance to that of native monolingual Spanish listeners whose L1 contains fewer vowels than Dutch. AusE listeners were able to discriminate all Dutch vowel contrasts above chance. While there was no main effect of language background, an interaction language background x contrast revealed that AusE listeners more accurately discriminated the /I-Y/ contrast compared to Spanish listeners, suggesting some advantage for AusE listeners. The findings are discussed in relation to models of non-native and L2 speech perception together with a comparison of vowel acoustic properties across AusE, Spanish and Dutch.