Vowel Length and Intelligibility in English as a Lingua Franca.

This study examines the Lingua Franca Core (LFC) claim that correct vowel length is essential for intelligibility in English as a Lingua Franca (ELF) interactions. Using audio tokens from 22 non-native English speakers of nine different native languages, vowel durations were measured and presented to 11 native Swedish listeners who identified vowel length in monosyllabic words. Results showed that listeners generally distinguished short and long vowels based on both expected vowel length and actual vowel duration, supporting the LFC's emphasis on vowel length for intelligibility, though some exceptions were noted. While short vowels lengthened before voiced consonants, voicing did not significantly influence listeners' vowel length identification. The study concludes that vowel length is a relevant focus for ELF pronunciation teaching but highlights the complexity of ELF vowel production and calls for further research with more diverse listener and speaker populations.