Non-native vowel perception in a 4iax task: the effects of acoustic distance

The effects of acoustic versus phonetic similarity in non-native vowel perception have been the focus of many second language (L2) speech perception models, examining how non-native sounds are perceived and assimilated by listeners. These models use perceptual discrimination tasks (e.g., AX, AXB) that may elicit different modes of perception depending on the memory load and linguistic experience required in each. This paper examined how native Australian-English (AusE) speakers perceived naturally-produced Dutch vowels in a 4IAX task, less commonly used but believed to elicit more continuous perception and bypass conscious linguistic processing. Participants listened to six Dutch vowel pairs spoken by varying speakers and chosen for their acoustic distance from AusE vowels. Results showed that /ɪ-i/ was the least accurately discriminated compared to other vowel pairs, confirming predictions that L1-L2 acoustic distance is a driving force in non-native speech perception and suggesting that linguistic experience may affect perception during the 4IAX task.