This study examined three ways that perception of non-native phones may be uncategorized relative to native (L 1) categories: focalized (predominantly similar to a single L 1 category), clustered (similar to> 2 L 1 categories), and dispersed (not similar to any L 1 categories). In an online study, Egyptian Arabic speakers residing in Egypt categorized and rated all Australian English vowels. Evidence was found to support focalized, clustered, and dispersed uncategorized assimilations. Second-language (L 2) category formation for uncategorized assimilations is predicted to depend upon the degree of perceptual overlap between the sets of L 1 categories listeners use in assimilating each phone within an L 2 contrast.
Faris, M., Best, C. T., & Tyler, M. D. (2016). An examination of the different ways that non-native phones may be perceptually assimilated as uncategorized. Journal of the Acoustical Society of America, 139(1), EL1-EL5. https://doi.org/10.1121/1.4939608