Onset-rime coarticulation in the production of /dai/ and /stai/ by four-year-old Scottish English speaking children: preliminary results

Patterns of coarticulation between onset and rime in the speech of six Scottish English speaking children aged 4 years is examined in the words dye /dai/ and sty /stai/. F2 is 272Hz lower at the burst following /st/ than following /d/. The lower F2 after /st/ in the onset-rime transition is accompanied by a higher F2 during /ai/’s diphthongal offglide. Moreover, the overall shapes of the F2 trajectories are similar, and the frequency difference in F2 at the stop burst correlates with difference in duration between complex and singleton onset. These facts suggest that in the /st/initial word the diphthong is apparently initiated earlier with respect to the stop burst — and therefore that the intial portion of the vowel opening gesture is masked acoustically by the preceding stop to a greater extent after the cluster than after the singleton. This interpretation supports models of intergestural timing in which hierarchical prosodic nodes (in this case, the onset) enable non-local gestural organisations. The syllable onset provides a fixed anchoring point for the following vowel (a "C-centre") which results in greater acoustic masking when the onset is complex.