Auditory Icons: A New Class of Auditory Warning Signals for Use in Intelligent Transportation Subsystems

The sounds traditionally used as auditory displays and warnings in truck cabs have no meaning outside the context of the particular environment in which they are used. If an operator changes equipment, often an entirely new set of warnings and the associations between the various sounds and the situations to which they refer must be learned, while at the same time long-standing associations learned from previous experience must be overcome. Furthermore, research has shown that people operating complex systems can effectively differentiate only five or six different alarm or warning sounds. In an attempt to overcome these shortcomings, a new class of auditory display, referred to as auditory icons, is being investigated. Whereas conventional auditory displays are defined by their particular acoustic parameters, auditory icons are caricatures of naturally occurring sounds. Such sounds are representational in that they have stereotypical meanings across large portions of the population. This paper describes an effort to establish a rigorous process for selecting and evaluating auditory icons for use in commercial vehicles. Results of a pilot study used to validate the methodology are presented with preliminary results of a simulator-based experiment using auditory icons as collision avoidance warnings.