Factors determining perceptual and acoustic similarity between native and non-native vowels

Anna Balas, Magdalena Wrembel, Kamil Kaźmierski, Jarosław Weckwerth

Abstract: This study investigates perceptual assimilation of Norwegian vowels to Polish vowels, based on a task completed by 15 learners of Norwegian. The perceptual similarity is juxtaposed with the acoustic similarity operationalized as the Euclidean distance. The socalled marked lip rounding (as in the case of Norwegian front and central rounded vowels) and vowel length are examined as factors which may potentially influence perceptual assimilation. AIC comparison suggests that a model including Euclidean distances based on F1 and F2 only is better than a model including F3 as well. Neither vowel length nor marked lip rounding turned out to be significant in predicting assimilation count, but the interaction of lip rounding with Euclidean distance proved to be significant, meaning that for vowels with unmarked lip rounding, there is a stronger effect of Euclidean distance on assimilation. The conclusion for non-native vowel perception research is that marked lip rounding could be a factor to analyze when considering assimilation patterns.