Across session spatial stability of the tongue-jaw complex in alveolar closure

Abstract

The movements of the tongue, lips, and jaw were transduced by electromagnetic midsagittal articulography. A single session included 20 repetitions of /pap/, /tat/, and /sas/ imbedded in a carrier phrase at normal, slow, and fast speech rates. Seven talkers completed three sessions at 1-week intervals. Reported here are measures of across session stability of tongue and jaw spatial synergies for alveolar closure at normal rates. Preliminary analyses indicate that idiosyncratic organization of the tongue and jaw for alveolar closure is relatively stable within and across sessions. However, across session stability, in terms of the relative contribution of the tongue and jaw towards closure and motor equivalence covariability of the summed tongue-jaw, the jaw, and the derived independent tongue displacements, is sensitive to variations in normal speech rate. For example, tongue-jaw synergies varied when the difference between session average duration of the tongue and/or jaw gestures approached 30%. [Work supported by NIH DC-00121 to Haskins Laboratories and University of Illinois research grant.]