Distinctiveness and Assimilation in Vowel Perception in a Second Language

Area of Science:

• Phonetics and Phonology
• Second Language Acquisition
• Psychoacoustics

Background:

• Understanding how second language (L2) vowel categories are established is crucial for L2 speech perception.
• The perceptual distinctiveness of L2 vowels relative to native language (NL) vowels and other L2 vowels influences perception.
• The 1st formant (F1) and 2nd formant (F2) vowel space is a key acoustic framework for analyzing vowel perception.

Purpose of the Study:

• To investigate the impact of distinct L2 vowel category establishment on L2 vowel perception.
• To examine how L2 vowels are established in relation to NL counterparts and adjacent L2 vowels within the F1 × F2 space.
• To compare L2 vowel perception and category establishment between Chinese-native (CN) and English-native (EN) listeners.

Main Methods:

• Identification of 12 natural English monophthongs by CN and EN listeners.
• Categorization and rating of synthetic English vowels /i/ and /ɪ/ in the F1 × F2 space for both listener groups.
• Categorization and rating of Chinese vowels in the F1 × F2 space for CN listeners.

Main Results:

• EN listeners demonstrated significantly higher accuracy in English vowel identification compared to CN listeners.
• EN listeners showed a distinct establishment of English vowels, while CN listeners exhibited varied establishment patterns (both, one, or neither).
• CN listeners' perception of English vowels correlated with the perceptual distance to their Chinese counterparts and to adjacent English vowels.

Conclusions:

• Effective L2 vowel perception hinges on the listener's ability to establish L2 vowel categories distinctly.
• Distinctiveness from both NL counterparts and neighboring L2 vowels is essential for successful L2 vowel category formation.
• The findings highlight the importance of perceptual spacing in the F1 × F2 space for L2 phoneme acquisition.