An earcon is a brief, distinctive sound used to represent a specific event or convey other information. Earcons are a common feature of computer operating systems and applications, ranging from beeping when an error occurs to the customizable sound schemes of Windows 7 that indicate startup, shutdown, and many other events.

The name is a pun on the more familiar term icon

Computer icon

A computer icon is a pictogram displayed on a computer screen and used to navigate a computer system or mobile device. The icon itself is a small picture or symbol serving as a quick, intuitive representation of a software tool, function or a data file accessible on the system. It functions as an...

 in computer interfaces. Icon sounds like "eye-con" and are visual, which inspired D.A. Sumikawa to coin "earcon" as the auditory equivalent in a 1985 article, 'Guidelines for the integration of audio cues into computer user interfaces.'

Although the term is most commonly applied to sound cues in a computer interface, examples of the concept can be seen in broadcast media such as radio and television:

• The alert signal used to indicate a message from the Emergency Broadcast System
  Emergency Broadcast System
  The Emergency Broadcast System was an emergency warning system in the United States, used from 1963 to 1997, when it was replaced by the Emergency Alert System.-Purpose:...
  
  
• The signature three-tone melody used to identify NBC in radio and television broadcasts

Earcons are generally synthesized tones or sound patterns. The similar term auditory icon refers to recorded everyday sounds that are used for the same purpose.