Effects of secondary tasks on auditory detection and crossing thresholds in relation to approaching vehicle noises

- We examined effects of secondary tasks on participants' ability to detect vehicles and make crossing judgments.
- Vocal cell phone conversations negatively affected vehicle detection distances, but texting conversations did not.
- Judgments of safe crossing thresholds were not affected by either type of secondary task (vocal or texting conversation).

Research suggests an association between distracting environmental sound stimuli and poorer performance in detecting and localizing approaching vehicles using auditory cues. However, no studies have investigated the distractive potential posed by intrapersonal distractors in the context of pedestrian auditory perception. We examined the effects of holding naturalistic vocal and texting cell phone conversations on participants' auditory detection of approaching vehicles and crossing thresholds in a non-visual simulated setting. Ninety-nine adults were randomly assigned to conditions of vocal conversation, texting conversation, or a control group and completed an auditory vehicle detection task. Participants in the vocal cell phone conversation group detected vehicles at significantly shorter distances than participants in the control group. The concurrence of a secondary task did not affect the distances at which participants deemed vehicles noise too close for them to safely cross (i.e., crossing thresholds). Implications for future research and injury prevention are discussed.