The production of consonant harmony in child speech

Consonant harmony, an assimilatory process affecting non-adjacent consonants, is found in both child and adult speech. While adult consonant harmony appears to be a phonological process, child consonant harmony has distinct properties that make a purely phonological explanation difficult. Child consonant harmony is found in the speech of some learners acquiring a language that does not have consonant harmony. Data from child consonant harmony is also distinct. In adult systems, sibilant harmony dominates (Hansson 2001), while in child systems velar and labial harmonies are most common (Stoel-Gammon and Stemberger 1994). Recent work on other systematic errors in child speech has arguably revealed a non-phonological source for neutralizations and substitutions (Gibbon 1990, Scobbie et al. 2000). These two cases were previously explained via the phonology, however, acoustic and articulatory analysis show that the expected contrast was being produced by the speaker but was too weak to be perceived. These studies raise the question of other systematic errors in child speech, such as consonant harmony. Could consonant harmony in children be the result of a developing motor system and not the phonology? Previous work on child consonant harmony credits this process solely to the phonology e.g. Stoel-Gammon and Stemberger, 1994; Goad, 1995; Pater & Werle, 2001. A recent treatment by Hansson (2001), however, notes the similarities between consonant harmony and slips of the tongue. He concludes that while adult consonant harmony may be fully synchronic, it may have its source in the domain of speech planning. These similarities also call into question whether child consonant harmony is the result of this domain. Having identified three possible sources for child consonant harmony; the phonology, a developing motor system and the domain of speech planning, a study will be presented that tests the hypothesis that child consonant harmony is the result of a developing motor system. The results of both the articulatory and acoustic study indicate that the motor system is faithfully executing the command to produce a harmonized form. This is evidence that consonant harmony is not the result of a developing motor system. While no evidence is produced that contradicts a phonological treatment, the facts of child consonant harmony may be better explained as having a source in the domain of speech planning.Arts, Faculty ofLinguistics, Department ofGraduat