The Vocal Joystick: Evaluation of voice-based cursor control techniques for assistive technology

Abstract

Purpose. Mouse control has become a crucial aspect of many modern day computer interactions. This poses a challenge for individuals with motor impairments or those whose use of hands is restricted due to situational constraints. We present a system called the Vocal Joystick which allows the user to continuously control the mouse cursor by varying vocal parameters such as vowel quality, loudness and pitch.Method. Evaluations were conducted to characterize expert performance capability of the Vocal Joystick, and to compare novice user performance and preference for the Vocal Joystick and two other existing speech based cursor control methods.Results. Our results show that Fitts' law, a well adopted model of human motor performance for movement tasks, is a good predictor of the speed – accuracy tradeoff for the Vocal Joystick, and suggests that the optimal performance of the Vocal Joystick may be comparable to that of a conventional hand-operated joystick. Novice user evaluations show that the Vocal Joystick can be used by people without extensive training, and that it presents a viable alternative to existing speech-based cursor control methods.Conclusions. The Vocal Joystick, with its ease of use, minimal setup requirement, and controllability, offers promise for providing an efficient method for cursor control and other forms of continuous input for individuals with motor impairments.