Not crazy after all these years? Perceptual grounding for long-distance vowel harmony

Long-distance (or ‘transparent’) vowel harmony systems have frequently been considered ‘unnatural’ and analyzed as ‘crazy rules’ (Bach & Harms, 1972) because they violate the principle of strict locality. Articulatory explanations for the phonetic grounding of vowel harmony are unable to extend to non-local processes, and attempts to re-analyze cases of transparent harmony as strictly local have been largely unsuccessful. In this paper, I present experimental evidence suggesting that vowel harmony may be perceptually (as well as articulatorily) grounded, and that this source of phonetic grounding does in fact extend to long-distance as well as local harmony. In a series of four experiments, subjects were presented with a nonsense word followed by an isolated vowel, and asked to report whether the isolated vowel had occurred in the preceding word. Subjects were consistently faster and more accurate in nonsense words which exhibited vowel harmony along the relevant feature dimension, regardless of locality. A fourth experiment included a task requiring subjects to identify whether the vowel occurred in a specific syllable, and here too they showed better performance on items with vowel harmony along the relevant feature dimension. I argue that strict locality is not a necessary component of a phonetically grounded theory of vowel harmony, suggesting that long-distance harmony can be analyzed as an explicitly non-local process without abandoning phonetic grounding.