J. A. S. Kelso
Ctr. for Complex Systems, Florida Atlantic Univ., Boca Raton, FL 33431
Previous work [Tuller and Kelso, Attn. & Perf. XIII (1990)] reported a transition in relative phase between glottal and lip movements as the rate of producing a VC syllable increased. However, the character of the transition could not be explored because of the large increments in rate selected by the speakers. Here, speaking rate was controlled using a metronome that began at 1 Hz and increased to 3.25 Hz in 0.083--Hz steps every 12 repetitions. Subjects repeated the target word ``opt,'' ``hopped,'' or ``top'' in time with the metronome while movements of their tongue tip, tongue blade, lower lip, upper lip, and jaw were tracked by an alternating magnetic field device, the Articulograph AG100. Analysis of the relative phasing between articulators confirmed the presence of a transition from VC to CV syllable structure at higher speaking rates. Results will be discussed with respect to the type of transition observed and the relative stability of different syllabic structures.