What are the sources of variation in the input, and how much do they matter for language acquisition? This study examines frequency variation in manner-of-articulation classes in child and adult input. The null hypothesis is that segmental frequency distributions of language varieties are unigram (modelable by stationary, ergodic processes), and…

The lexical variables of word frequency and neighborhood density were hypothesized to facilitate sound change to varying degrees. Twelve children with functional phonological delays participated in an alternating-treatments experiment to promote sound change. Results indicated word frequency was most facilitative in sound change, whereas dense…