In-Vehicle Noise Alters the Perceived Meaning of Auditory Signals

Research on driver perception and interpretation of auditory signals has generally been conducted under conditions of low-to-moderate ambient in-cab noise. In a series of four experiments, the effects of various ambient noise conditions on the perceived meaning of auditory signals were investigated. Noise conditions that may be realistically anticipated in the course of normal driving altered the perceived urgency and meaning of signals. The presence and extent of such changes was a function of the specific auditory signal, the ambient noise condition, and their interaction. The results indicate that in-vehicle auditory signal design criteria developed only under low-to-moderate ambient noise conditions are not likely to be sufficient. The significant signal-by-ambient noise interaction further suggests that multiple noise backgrounds must be considered.