Various schemes for easily and accurately transducing lip and jaw movements into an analog voltage have been explored. Considerations of cost, simplicity, linearity, and the need to maintain natural articulation in speech led to the development and construction of a device involving a simple optical system and a photocell. The device can track in any dimension the position of one or more tiny lights attached to the lips and/or jaw. Using the device a few simple experiments were conducted involving jaw deflection, velocity and acceleration. The experimental finding of Kozhevnikov et al. (Speech: Articulation and Perception, 1965) that the peak velocity of the lower lip on closing for a consonant varies proportionately with its maximum open position was found to be true of the jaw, too. [This research was partially supported by the National Institutes of Health, U. S. Department of Health, Education and Welfare, and the Office of Naval Research.]