Contextual variables related to inconsistent /s/ and /z/ production in the spontaneous speech of children.

The relationship between phonetic context and inconsistent productions of /s/ and /z/ in the spontaneous speech of three approximately three-year-old children was investigated using a nonlexically constrained segmentation, the VCnV syllable. Cn represents any number of consonants occurring between two vowels. The results indicate that of the speech segments surrounding /s/ and /z/ only the identity of consonants following these segments was significantly related to the accuracy of /s/ and /z/ production. The implications of the data for models of speech production are discussed.