Experiments in the application of isolated-word recognition to secondary driving controls for the disabled

Adaptive driving controls such as mechanical hand controls or electromechanical contact switches are now available which allow even the most severely impaired to drive. The residual functions, however, are all directed toward primary controls such as steering, braking, and accelerating, limiting the ability to operate secondary controls such as the horn, turn signals, ignition, and headlights, etc. In this paper, we discuss the application of speech recognition technology when operating these secondary controls. The performance of a speech recognition system inside a vehicle is studied, and the types of noise that degrade the recognition accuracy are also identified. Results are presented on the degradation in recognition performance caused by engine noise, fan noise, and interfering speech.