Vowel harmony in Optimal Domains Theory

This chapter introduces and motivates the idea of spans as relevant for suprasegmental phenomena in the area of tone and vowel harmony. This approach is offered as an alternative to the autosegmental view of assimilation as spreading. In the Optimal Domains Theory approach, a feature F is realized within a phonological constituent termed the F-span. A span is sponsored by a single anchor in the unmarked case, but in cases of harmony the span has a wide scope defined in terms of prosodic or morphological constituents. The Expression constraint requires that within an F-span all anchors should be specified for F. However, this constraint may conflict with feature occurrence constraints that restrict the affiliation of F.