Patent US 5,969,719

This invention provides a computer capable of displaying information in multiple windows and handling multiple audio signals in a manner convenient for a user. This is achieved in one embodiment of the present invention by audibly producing only one audio signal at a time, but allowing the user to monitor a second received audio signal by visually representing the second audio signal through a displayed icon. The display of the icon may vary over time, reflecting time-variable characteristics of the signal represented by the icon, thus enabling the user to monitor the audio signals that are received but not actually audibly produced. Examples of such time-variable characteristics include volume, semantics and pitch.