Timing of Glottal Movements in Plosive Production

Abstract

A model is presented for the primary parameter distinguishing plosive phonemes having the same place of articulation. This parameter is expressed in terms of the timing between the period of articulatory closure and a maximally fast change in glottal adjustment. For intervocalic plosives, the change in glottal adjustment is “cyclic,” either voiced-breathy-voiced, or voiced-open-voiced, and requires at least 100 to 150 msec. In the prevocalic position (after an open glottal adjustment), the change is unidirectional, from open to voiced, except for certain phonoaspirated plosives in which the change is approximately open-voiced-breathy-voiced. The model is unusual in that (1) it is based on the adjustment of the glottis, and not on the actual occurrence of voicing, and (2) it takes into consideration the dynamic constraints inherent in changes of glottal adjustment. The adjustment of the glottis can be monitored by bypassing the articulatory closure with a low-resistance air path and recording the resulting air flow. Four intervocalic and four prevocalic categories of timing pattern are described that have the potential of supporting a phonemic distinction.