Vigilance for simultaneous auditory and vibrotactile signals

Abstract

In a vigilance situation Ss performed 3 separate 70 min. watches, an auditory one (A), a vibrotactile one (C) and a simultaneous auditory‐vibrotactile one (AC), to find if an improved detection rate might not be obtained by increasing the number of display channels to a single observer. Results showed that the AC channel had a significantly higher detection rate than either the A or C channels alone, the A channel being superior to the C channel. There was also a significant decrement over time for the A and C channels alone, but not for the AC channel. For both the A and C channels alone there was a significant increase in Ss' thresholds over time. There was an insignificant increase for the AC channel. Paralleling these changes were large increases over time in Ss' criterion (β) for the A and C channels, and a small increase for the AC channel. The auditory and vibratory senses thus appeared to be interdependent.