What does cross-linguistic perception tell us about the phonetics-phonology interface?

The internal representation of linguistic information has been the subject of much debate. Recent work has shown that brain activation in response to different categories of segments, such as obstruents or approximants, triggers different neural networks. This work examines the perception of English and Malayalam native speakers’ perception of seven fricatives, /f, s, ʂ, ʃ, ɕ, x, h/, to examine what the acoustic-perceptual grouping of segments within a class reveals about internal representation. The results indicated distinct grouping of the fricatives into three categories, anterior /f/, sibilant /s, ʂ, ʃ, ɕ/, and posterior /x, h/. We also observed an expansion in the perceptual space for sibilant fricatives as a function of perceiver L1. We suggest the distinct clustering in the perceptual space reflects the internalized representation of these segments. Segment groupings are formed on the basis that they share class features, supporting the notion that class membership is dictated, at least in part, by acoustic-perceptual relationships. We suggest that the expansion is related to language exposure specific to Malayalam, which has three sibilant fricatives in its inventory, /s, ʂ, ɕ/. The result of the exposure is an expansion and more well-defined category boundaries for segments in the native inventory.