Development of articulatory measuring system by using magnetometer and optical sensors

This paper introduces a useful measuring system for monitoring articulatory movements. The system is made up of magnetometer and optical sensor units. The magnetometer unit consists of sensors having two amorphous alloy cores and small permanent magnetic rods, which are attached to the tongue surface as pellets. A measuring principle is based on a change in the intensity of the magnetic fields related to distances between the rods and sensors. On the detection of the rods’ positions, tilting and lateral movements of the rods on the tongue surface cause measurement errors, and such troublesome movements are serious problems in the magnetic sensing system using similar principles. The system developed here is able to reduce these errors with symmetrical arrangements of magnetometer sensors around the subject’s jaw. The optical sensor, which was previously developed, consists of a position‐sensitive device (PSD) which detects positions of the light‐emitting diodes (LEDs) which are attached to the lips, jaw, ...