A study on the source of position estimation errors in a three-dimensional electromagnetic articulography

摘要

This paper presents a study on tire possible source of position estimation errors in a three-dimensional electromagnetic articulograpy which is used for observing articulatory movements during the production of speech. In our method, the position of the receiver coil is determined based on a nonparametric representation of the magnetic field so that the error between the measured and predicted receiver signals is minimized. An experiment was performed to examine the accuracy of this position estimation method showing the dependence of the estimation errors on the direction of the receiver coil. To determine the cause of these results, the position estimation error was compared with the signal sensitivity and signal prediction error. Then it was shown that the position estimation error was accompanied by the error of tilt angle estimation. In addition, weak correlations found implies that the signal sensitivity and signal prediction error partly explain the cause of the position estimation error, although they didn't have an evident dependence on the direction of the receiver coil.