de Jong, Lim & Nagao - 1 Phase Transitions in a Repetitive Speech Task as Gestural Recomposition. Kenneth de Jong, Byung-jin Lim, & Kyoko Nagao * Department of Linguistics, Indiana University Abstract. This paper examines glottal movement data in rate-controlled repetitions of CV (onset consonant + vowel) and VC (vowel + coda consonant) structures. It replicates Tuller & Kelso’s (1991) observation of rate-induced phase transitions in glottal behavior. Specifically, for voiceless consonants peak glottal opening for CV’s are similar at fast and slow rates. The timing for VC’s at slow rates differs from that of CV’s, but changes at fast rates to become like CV’s. Additional aspects of rate-induced changes in glottal behavior were also found, however. For 'voiced' consonants, CV’s show the same change in glottal timing as do voiceless post-vocalic VC’s. In addition, apparent phase transitions may involve both the timing and magnitude of the gestures and as well as which glottal gestures the speakers implement. Hence, VC phase transitions also seem to involve a change in gestural composition, rather than just a re-coordination of the same gestures. *Work supported by the NIDCD (grant #R03 DC04095-01A2) and by the NSF (grant #BCS-9910701). We also express deep appreciation to Anders Lofqvist, without whose seemingly endless patience and remarkable expertise, none of this work could have been done. We also acknowledge Mafuyu Kitahara and Bushra Zawaydeh for their help on this project. This paper was presented as paper 2aSC11 at the 142nd meeting of the Acoustical Society of America, the abstract of which appears in the Journal of the Acoustical Society of America, 110: 2657.