Phonological adaptation of English vowels with the Persian vowel system

Phonological adaptation refers to phonological changes applied to loanwords to make them match the phonological system of the borrowing language. The present research addresses the phonological adaptation of English vowels with the Persian vowel space based on the theory of perceptual assimilation. The theory of perceptual assimilation assumes that phonological adaptations are minimal phonetic changes in the acoustic space. Thus, we assumed that the adaptation of English vowels with the Persian sound system reflects the acoustic distances between vowels in a comparative vowel space (English-Persian). Two experiments were carried out in this research to test the predictions of this theory. First, in a production experiment, we computed the acoustic distances between Persian and English vowels by comparing them in a unified vowel space. Then, in a follow-up perception experiment, we examine to what extent the perception of English vowels reflects the phonetic distances between vowels of the two languages found in the production experiment. Results revealed that the perception of English vowels by non-native Persian listeners reflects, to a large extent, the acoustic proximity between vowel categories of the two languages. The results are interpreted as suggesting that the adaptations of English vowels with the Persian vowel system take place in perception, as assumed by the theory of perceptual assimilation, and are defined as acoustically minimal transformations