Licensing and vowel patterns
This chapter reviews what has been accomplished in this book and looks ahead to issues that remain to be resolved. This first section consolidates the leading results of the research in this work. In the next section, I identify topics that need attention in the future in order to make further progress.
As discussed in chapter 1, this work revolves largely around two themes: (1) how word position affects the way in which vowels function in sound patterns, and (2) how aspects of the perception and production of speech affect vowel patterns. Bearing on these issues, a fundamental insight this work brings to the understanding of vowel phenomena is that diverse systems in numerous languages serve to prevent the expression of distinctive phonological content solely in a weak position. Further, these patterns are hypothesized to have functional underpinnings such that they serve in large part to reduce perceptual difficulty in language.
The formal approach advanced in this work posits licensing constraints as the imperative that is the common factor for the vowel phenomena under study. These licensing constraints are cast as markedness constraints. Effects that involve licensing by a prominent position are united under the umbrella of a generalized prominence-based licensing constraint schema. This schema is such that prominence-based licensing constraints can be satisfied by multiple configurations for the restricted element: identity licensing, indirect licensing, direct licensing, and absence of the element, with the solution being determined by the interaction with other constraints in the grammar of language.