New optical method for recording lip and jaw movements.

A new optical recording system for labial and mandibular movements during speech is presented. An optical position sensor is used to detect the positions of small infrared LEDs attached to the lips and to a rigid wire fixed to the mandibular teeth. The system allows continuous data collection of eight points at a sampling period of 4 ms with a high accuracy and a very fast response. Some preliminary data are given for one subject. [ABSTRACT FROM AUTHOR]