New method for fast continuous measurement of the lip-opening area

An electronic device for measuring the articulatory parameter ’’lip-opening area’’ is presented. The measurement rate is 50 values per second. Utilizing the video signal of a TV camera, the device produces a voltage proportional to the dark area of the mouth opening surrounded by a bright boundary (lips painted white). High contrast is achieved by using fluorescent paint and ultraviolet illumination. As an example, a measured lip-opening area is shown as a function of time.