Abstract
The article describes a test method to compare the unimodal and bimodal stimulus presentation in a visual step function tracking task. Thirty-six right-handed male college students volunteered to serve as subjects for the experiment. They were all between 18 and 25 years old, and had normal vision and hearing. The test is performed with the aid of a Versatile Electronic Tracking Apparatus which is developed at the Kansas State University. The experiment includes three different conditions, and the results indicate that a redundant auditory input can either facilitate or inhibit certain aspects of the performance. These data were consistent with a perceptual model for bimodal stimulation.