The effect of speech interface accuracy on driving performance

With the proliferation of cell phones around the world, governments have been enacting legislation prohibiting the use of cell phones during driving without a “hands-free” kit, bringing automotive speech recognition to the forefront of public safety. At the same time, the trend in cell phone hardware has been to create smaller and thinner devices with greater computational power and functional complexity, making speech the most viable modality for user input. Given the important role that automotive speech recognition is likely to play in consumer lives, we explore how the accuracy of the speech engine, the use of the push-to-talk button, and the type of dialog repair employed by the interface influences driving performance. In experiments conducted with a driving simulator, we found that the accuracy of the speech engine and its interaction with the use of the push-to-talk button does impact driving performance significantly, but the type of dialog repair employed does not. We discuss the implications of these findings on the design of automotive speech recognition systems.