Predicting pharyngeal diameter from anterior tongue pellet positions in Swedish
Michel T. T. Jackson, Richard S. McGowan · The Journal of the Acoustical Society of America · 2007
One goal of phonetics is to quantitatively understand articulation in human speech production. As part of this goal, we are interested in the extent to which some vocal tract dimensions, specifically midsagittal pharyngeal diameters, are predictable from flesh points of the anterior tongue. In a reanalysis of x rays of speakers producing Swedish vowels, we modified previous procedures [Whalen et al., J. Speech, Lang. Hear. Res. 42, 592–603 (1999); Nix et al., J. Acoust. Soc. Am. 99, 3707–3717 (1996)] to predict pharyngeal diameters from pseudo-pellet positions. We used principal component analysis to reduce the number of pellet degrees of freedom from eight to three prior to applying linear regression from these three independent variables to each of several dependent pharyngeal diameters. Except for the regions around the laryngopharynx and uvula, the pharynx dimensions predictable from linear regressions were significant at the p<0.05 level. Numerical experiments show that it is crucial to reduce the number of independent variables in tests of statistical significance. [Work supported by Grant No. NIDCD-001247 to CReSS LLC.]