ISCA Archive ICSLP 1992
ISCA Archive ICSLP 1992

Improvements of magnetometer sensing system for monitoring tongue point movements during speech

Yorinobu Sonoda, Kohichi Ogata

The purpose of this paper is to present design improvements of magnetometer sensing system for monitoring tongue point movements during speech. The measuring principle is similar to that used in earlier prototype system. The system basically consists of two magnetometer sensor units and a small permanent magnetic rod as a pellet which is attached to a desired point of tongue surface. Serious problems with tilting movements of the tongue are encountered when magnetic sensing systems make use of static magnetic fields as well as alternating ones. If each axis of the sensor units and the rod are not mutually parallel, the strength of the signal detected by the sensor decreases, and therefore estimated distances result greater than actual ones. These problems were resolved by a special hardware and software architecture which automatically detects and corrects tilting angles. The measuring principle and its technical realization are described, and preliminary experimental results are presented.