Strident harmony from the perspective of an inductive learner

In languages with strident harmony, stridents within a particular domain are required to have the same minor place of articulation. Harmony is often required only of stridents within a root or stem morpheme, and doesn't trigger alternations. Harmony is also often quite local, applying exclusively or more strongly between stridents in the same or adjacent syllables. Finally, harmony may be morpheme specific, triggering alternations in some affixes but not others. All of these specifics of a given harmony pattern give rise to exceptions to harmony at the level of the word, and may require a morphologically parsed learning corpus in order to be acquired. This paper explores the learnability of strident harmony in text corpora from three languages: Nkore-Kiga (Bantu), Papantla Totonac (Totonacan) and Navajo (Athapaskan). The analyses show that word level exceptions largely obscure the harmony pattern as an overall phonotactic in a language. The three languages also serve as a test of the Projection Induction Learner (Gouskova & Gallagher 2020), which is found to be successful when the generalizations in the data are strong but may fail in the face of patterned exceptions.