a1 Stanford University
This paper reports on a longitudinal study of the acquisition of the voicing contrast in American English word-initial stop consonants, as measured by voice onset time. Four monolingual children were recorded at two-week intervals, beginning when the children were about 1; 6. Data provide evidence for three general stages: (1) the child has no contrast; (2) the child has a contrast but one that falls within the adult perceptual boundaries of one (usually voiced) phoneme and thus is presumably not perceptible to adults; and (3) the child has a contrast that resembles the adult contrast. The rate and nature of the developmental process are discussed in relation to two competing models for phonological acquisition and two hypotheses regarding the skills being learned.
(Received December 01 1978)
[*] This research is part of the activities of the Stanford Child Phonology Project and has been supported by a National Science Foundation Grant (BNS 76–08968) to Charles A. Ferguson and Dorothy A. Huntington, Departments of Linguistics and Hearing and Speech Sciences, Stanford University. We gratefully acknowledge their support during all phases of the research. We would also like to thank Harold Clumeck, John Kingston and Deborah Ohsiek for their assistance at various stages of the data collection and Lise Menn, Carl Muller and Marsha Ziatin Laufer for comments on an earlier version of this paper. A summary of this study was given on 1 October 1977 at the Second Annual Boston University Conference on Child Language Development, and a preliminary version of this paper with a more detailed discussion of each subject's data appears in PRCLD 14 (1977). Address for correspondence: Dept. of Linguistics, Stanford University, Stanford, California 94305.