Introduction

This chapter provides an Optimality Theoretic analysis that accounts for the existence of laryngeal cooccurrence restrictions. Cooccurrence restrictions prohibit the coexistence of certain segments within some domain, typically the morpheme or the word. The cooccurrence restrictions listed in restrict several different types of segments from cooccurring: aspirated segments, identical segments, homorganic segments, non-identical sibilants, and voiced obstruents. Analyses of cooccurrence restrictions have had a major impact on phonological theory in two areas. First, the long-distance nature of these constraints-the fact that they operate over several intervening segments-makes them prime objects for research on the degree to which phonology operates over abstract representations. Second, the appearance of cooccurrence restrictions in a variety of genetically diverse, geographically-dispersed languages suggests that these restrictions are relevant to the search for phonological universals. The different degrees of cooccurrence restrictions result from the point of acceptable similarity being set differently in the different languages under consideration.