Individual-Level Contact Limits Phonological Complexity: Evidence From Bunched And Retroflex /R/

We compare the complexity of idiosyncratic sound patterns involving American English /r/ with the relative simplicity of clear/dark /l/-allophony patterns found in English and other languages. For /r/, we report an ultrasound-based articulatory study of twenty-seven speakers of American English. Two speakers use only retroflex /r/, sixteen use only bunched /r/, and nine use both /r/ types, with idiosyncratic allophonic distributions. These allophony patterns are covert, because the difference between bunched and retroflex /r/ is not readily perceived by listeners. We compare this typology of /r/-allophony patterns to clear/dark /l/-allophony patterns in seventeen languages. On the basis of the observed patterns, we show that individual-level /r/ allophony and language-level /l/ allophony exhibit similar phonetic grounding, but that /r/-allophony patterns are considerably more complex. The low complexity of language-level /l/-allophony patterns, which are more readily perceived by listeners, is argued to be the result of individual-level contact in the development of sound patterns. More generally, we argue that familiar phonological patterns (which are relatively simple and homogeneous within communities) may arise from individual level articulatory patterns, which may be complex and speaker-specific, by a process of koineization. We conclude that two classic properties of phonological rules, phonetic naturalness and simplicity, arise from different sources.