Locus equations derived from compensatory articulation

Locus equations are linear regressions of the onset of F2 transitions on their offsets. These functions vowel-normalize the F2 transitions such that they are able to characterize consonantal place categories. The purpose of this research was to determine if compensatory articulation due to bite blocks would alter the normally linear relationship between F2 transition onset and offset frequencies or alter the differential slopes and y intercepts of locus equations as a function of stop place. Six speakers, three male and three female, each produced /bVt/, /dVt/, and /gVt/ tokens for ten vowel contexts under normal and bite block conditions. Extremely linear and practically identical scatterplots were obtained in the two speaking conditions. No adaptation to the bite blocks was found when comparing locus equations derived from the initial versus the final bite block trial. Results are discussed in relation to the "orderly output constraint," which postulates a perceptual function for linearly related F2 transition end points within consonantal place categories.