Baseball's sight-audition farness effect (SAFE) When umpiring baserunners: Judging precedence of competing visual versus auditory events

Baseball umpires judge force-outs at first-base by comparing the sound of ball-mitt contact to the sight of foot-base contact. This study examines if distant observer judgments of the temporal order of visual versus auditory events are biased due to the slow speed of sound, or if judgments made from farther away systematically compensate for acoustic delays of sound. Seventy and 81 participants observed videos projected onto a gymnasium wall from 0, 100, or 200 feet, and made multisensory precedence judgments regarding which cue occurred first, visual ("safe") or auditory ("out"). Experiment 1 used visual flash versus auditory click; Experiment 2, colliding visual stimuli versus auditory click; Experiment 3, films of base-runners with basemen catching balls. Our findings confirm a sight-audition farness effect (SAFE) bias such that when visual information is impoverished, distant observers making multisensory precedence judgments typically do not fully compensate for acoustic delays due to the slow speed of sound, which can lead to disagreements. In short, distant fans will tend to have more of a bias to experience baserunners as safe, compared with nearby umpires.