Rhotic Metathesis Asymmetries in Romance: Formalizing the Effects of Articulation and Perception on Sound Change
Blevins & Garrett (1998, 2004) argue that rhotic metathesis occurs when listeners reinterpret an elongated [low F3] feature in a non-historical position. However, not all cases are amenable to this account, as no single phonetic property unifies the class of rhotics. We examine two cases involving intrasyllabic rhotic metathesis: rightward movement of /ʁ/ in French and leftward movement of /ɾ/ in Spanish. In Optimality Theory (Prince & Smolensky 1993), we formalize diachronic metathesis in terms of separate production and perception grammars, which account for the source of variance and the selection of innovative underlying forms, respectively. In production, gestural alignment constraints favor complete overlap of adjacent rhotic and vowel gestures, whose linear ordering is thereby rendered indeterminate. The output of the production grammar serves as input to the perception grammar, which maps surface forms to underlying forms in accordance with attested patterns of the language.