The goal of the current research was to measure and understand cognitive distraction stemming from voice-based technologies in the vehicle. Three controlled experiments evaluated 1) a baseline single-task condition, 2) issuing simple voice-based car commands, 3) listening to e-mail/text messages read by a “natural” pre-recorded human voice, 4) listening to e-mail/text messages read by a “synthetic” computerized text-to-speech system, 5) listening and composing replies to e-mail/text messages read by a “natural” voice, 6) listening and composing replies to e-mail/text messages read by a “synthetic” voice, 7) interacting with a menu-based system with perfect reliability, 8), interacting with a menu-based system with moderate reliability, and 9) using “hands-free” Siri to listen to and send text messages, update Facebook or Twitter status, and modify and review calendar appointments. Because each task allowed the driver to keep his or her eyes on the road and hands on the steering wheel, any impairment to driving must be caused by the diversion of attention from the task of operating the motor vehicle. We used a combination of primary-task, secondary-task, subjective, and psychophysiological indices to assess the mental workload of the driver using these voice-based technologies. The data extend the rating system for cognitive distraction developed by Strayer et al., (2013). The new ratings suggest that some voice-based interactions in the vehicle may have unintended consequences that adversely affect traffic safety. (Author/publisher)
Abstract