Understanding susceptibility to inattentional deafness in safety-critical environments.

INTRODUCTION: Dynamic occupational environments, such as construction sites, present workers with frequent changes, some of which pose serious risk. Workers are expected to detect and respond to these changes using sensory cues, including auditory warnings intentionally designed to draw attention to hazardous conditions. However, these cues often compete with high cognitive load, which can result in missed warning sounds, a phenomenon known as inattentional deafness. This study examines susceptibility to inattentional deafness during a simulated construction task. METHOD: Data were collected from 136 participants, including 72 individuals and 64 participants who worked in 32 pairs. All participants completed a mechanical-electrical assembly in a controlled laboratory environment with continuous construction noise. Before the task, participants received a brief pre-job-style briefing instructing them to stop work and move to a designated safety zone upon hearing any sound that could indicate hazardous energy. During the task, participants were randomly assigned to hear either an Air Horn or a Hissing cue and to work individually or collaboratively. Each participant (or pair) received three successive bursts of the assigned cue at 81, 83, and 85 dB presented at random intervals. RESULTS: Overall detection was 62%, with individuals detecting 58%, while pairs detected 71%. Sound type was the strongest determinant of noticeability, as the Air Horn was detected significantly more often than the Hissing cue. Increasing volume produced modest improvements in detection, and pair collaboration was beneficial, although the improvement did not fully align with probabilistic expectations of redundancy. Human factors such as fatigue, emotional state, and perceived task difficulty did not significantly predict detection. CONCLUSIONS AND PRACTICAL APPLICATIONS: These findings underscore the importance of highly distinguishable auditory warnings and system-level designs that account for the inherent limitations of human attention in safety-critical work environments.