Vowel final noise in child coda /s/

Child speakers of American English in the age range 2;6-3;6 often produce vowel final noise (VFN), or preaspiration, for [-voice] labial and velar stops in coda position of monosyllabic words [e.g., Shattuck-Hufnagel, Hanson, and Zhao, “Feature-cue-based processing of speech: A developmental perspective,” in Proc. ICPhS 2015]. In contrast, the female caregivers of these children produce VFN less often than the children, with significantly shorter durations. The current work extends the earlier work by studying a fricative, /s/, in coda position. Data from the same nine child/adult pairs are used. While the coda stops were all preceded by the vowel /ʌ/, the corpus includes two words with coda /s/, Gus and goose, allowing the observation of possible vowel effects. Preliminary analysis of a subset of the data shows that, as for coda stops, children are more likely than adults to produce VFN, with longer durations. However, adults show a vowel effect, being much more likely to produce VFN when /s/ follows /ʌ/ than when it follows /u/. A vowel effect is not observed for the child subjects.