A comparison of glossometric measurements of tongue position with magnetic resonance images of the vocal tract

The use of an opto‐electronic sensing device called a “glossometer” for measurement of tongue position during vowel production has been previously reported [Smith et al, Biomedical Engineering V: Recent Developments, edited by S. Saha (Pergamon, New York, 1986)]. However, while repeatability of this measurement has been well established, its accuracy has not been established due to the lack of an alternative, low‐risk technique for comparison. Recently, magnetic resonance (MR) images have been used to obtain vocal tract measurements. [Lakshminarayanan et al., RSNA, Work in Progress—Physics 173(P), 411 (1989)]. In this study, the performance of both systems was evaluated and compared using three custom‐made, tongue‐palate spacers to hold the tongue steady at three different positions. Distances measured using the two systems were compared with direct measurements of the spacers. It was found that distances measured from the MR images were accurate to within 2 mm in the worst case, but the glossometer demon...