Abstract
Multimodal interfaces have been identified as a possible solution for reducing the visual and motor demands of small devices such as cell phones. In a within-subjects factorial experiment, we explored where audio is useful in a cell phone interface that supports database applications. Participants sat at a desk and drove in a car simulator while choosing a hotel from a descriptive long list. We compared participants' performance with and without the option to listen to the information while it was presented in text. Participants rarely preferred or used the audio option while seated. A substantial number preferred and used the audio option while driving, especially when the hotel choice task was more difficult. Those who chose the audio option looked less at the phone, but increased their task time and did not improve their driving performance. We discuss implications of reading and listening for safety and design.