Thesis (M.S., Psychology) -- University of Idaho, 2016 | Auditory perception is important in the pedestrian environment. Recent research suggests an association between distracting environmental sound stimuli and poorer performance in detection and localization of approaching vehicles. The present study investigated the effects of secondary tasks (holding naturalistic vocal and texting cell phone conversations) on participants’ detection of approaching vehicles and crossing thresholds. Ninety-nine adults were randomly assigned to conditions of vocal conversation, texting conversation, or a no secondary task control group and completed an auditory vehicle detection task. Vehicle detection distances were significantly smaller in the vocal cell phone conversation group than in the control group, an effect that became stronger as the level of speed increased. Crossing thresholds were not affected by the concurrence of a secondary task. Implications for future research and injury prevention are discussed.