Extreme stop allophony in Mixtec spontaneous speech: Data, word prosody, and modelling

•We examine lenition of obstruents in a spontaneous speech corpus of Yoloxóchitl Mixtec (ISO xty), a language with fixed stem-final stress and a complex tonal inventory.•Measures of duration, voicing during constriction, and allophone type were examined.•Onset obstruents of unstressed syllables are lenited more than onset obstruents of stem-final stressed syllables.•Duration is a strong predictor of the degree of lenition, but the functional status of the morpheme is also important.•Modeling of the reduced allophones with deep neural networks resulted in high accuracy in the detection of stop closure (>95%), and fairly high (>70%) accuracy in detecting highly frequent reduced allophones.