Sound change in child language: a study of inter-world variation

The goal of this study is to retrace in minute detail a single step forward in the phonological development of a German-speaking child. The sound change under focus is the acquisition of velar stops in word-initial positions. Naturalistic data were collected on a daily basis over a period of approximately one year (3;4.9 - 4;3.20) until the process was nearly completed. Production accuracy was found to be under the influence of four factors--the nature of the velar stop (voiced or voiceless), the subsequent context, lexical stress and the individual word in which the critical consonant appeared. Progress was made not globally but in different subdomains at different points in time. Each phonological constellation gave rise to a distinct acquisitional pattern. While the velar stops were accurately produced before the alveolar nasal, they tended to be omitted before the rhotic and supplanted by the alveolar stops before the lateral. An attempt is made to identify the locus of the changes in a developing processing system consisting of linguistic units (nodes) and their interrelationships (associations). A comparison of the effects of inefficient nodes and those of inefficient associations suggests that learning in this child takes place by strengthening the associations rather than increasing the efficiency of processing on the nodes. Because modifying individual associations is quite a local repair process, it is argued that the acquisition of a new segment does not normally occur across the board. Instead, it is more appropriately conceived of as a gradual spread through the lexicon.