Suitability of a UV-based video recording system for the analysis of small facial motions during speech

The motion of the face carries great importance in research about speech production and perception. The suitability of a novel UV-based video recording system to track small facial motions during speech is examined. Tests are performed to determine the calibration and system errors, as well as the spatial and temporal resolutions of the setup. Results of the tests are further evaluated through kinematic data of the upper-lip, recorded from human speech, as this articulator typically shows the smallest movements, which would be the strongest test for any movement recording equipment. The results indicate that the current system, with a resolution slightly better than 1 mm, is capable of resolving the relatively small upper-lip motions during the production of normal speech. The system therefore provides an effective, easy-to-use and cost-effective alternative to more expensive commercial systems.