In this article we examine earcons, which are audio messages used in the user-computer interface to provide information and feedback to the user about computer entities. (Earcons include messages and functions, as well as states and labels.) We identify some design principles that are common to both visual symbols and auditory messages, and discuss the use of representational and abstract icons and earcons. We give some examples of audio patterns that may be used to design modules for earcons, which then may be assembled into larger groupings called families. The modules are single pitches or rhythmicized sequences of pitches called motives. The families are constructed about related motives that serve to identify a family of related messages. Issues concerned with learning and remembering earcons are discussed.