The Acquisition of Vowel Harmony from Simple Local Statistics

Vowel harmony denotes a class of phonotactic constraints which limit which vowels can co-occur in words. The characteristics of harmony systems have been well-researched from theoretical, typological, and developmental perspectives. Children are sensitive to harmony very early in their development, as young as seven months, so the mechanisms responsible for harmony acquisition must be able to identify its presence as well as the specifics of individual vowel harmony systems with little input. Prior computational work has sought either to detect the presence of harmony without describing the specific implementation or to describe a specific implementation when the general details are known beforehand. We present a new computational acquisition approach inspired by phonological notions of restrictiveness which succeeds in automatically detecting harmony in some language and describes the gross characteristics of the underlying harmony grammar without prior knowledge about the type of system to expect.