Rate manipulation and stability of onset and coda structures

Abstract

Stetson (1951) noted that singleton coda consonants, such as in the word ‘‘eat,’’ will shift to onset consonants, such as in the word ‘‘tea,’’ when the syllable is repeated at fast rates. Tuller and Kelso (1991), replicating Stetson’s effect, claim glottal phasing to be the relevant collective variable for examining syllable structures, and posit a dynamical model in which onsets represent a mode of coordination into which the articulatory system gets attracted. The present paper reports an experiment wherein syllables consisting of /i/ and labial stops are elicited in various rate-changing conditions. Speech rate is controlled with a metronome. Results partially support Tuller and Kelso’s model in that coda /p/ and /b/ show shifts in voice onset time to the stable values (expressed in absolute milliseconds) exhibited by onsets under increases in speech rate. In addition, results show hysteresis on the rate at which these shifts occur. However, the data show that coda configurations are also stable. When occlusion duration is measured, codas are stable across rates, while onsets are instable, shifting from longer values into the stable values exhibited by the codas. Thus, both onset and coda structures represent stable configurations, though of very different types.