Perceptual Assimilation of Arabic Voiceless Fricatives by English Monolinguals

Native language experience strongly influences non-native speech discrimination. According to the Perceptual Assimilation Model (PAM) [1], discrimination is most accurate when two non-native sounds map onto different native phonemes (Two-Category assimilation), poorer when they differ in goodness-of-fit to the same native phoneme (Category-Goodness assimilation), and worst when perceived as equally good or poor versions of the same native phoneme (Single-Category assimilation). The Three Factor Model [2] suggests that discrimination accuracy is poorer at a 1500 ms inter-stimulus interval (ISI), when only phonemic information is available, than at 500 ms, when both phonemic and phonetic information is available. To test the models, monolingual English participants assigned Arabic fricatives to English categories, and discriminated contrasting fricative pairs in an AXB task with a 500 ms or 1500 ms ISI. PAM discrimination predictions were upheld, but there was no influence of ISI.