Applications (11b 11d) and data files (11a 11c 11e) for a communication device (10) enabling the device to use a segment of a media or multimedia file (11a) (an audio file or one or more components of an audio-video file) stored in the communication device (10) to alert a user of the communication device (10) to the occurrence of an event, and to do so in a way that conserves memory. The invention provides an offset selector application (11b) by which a user is able to indicate that a particular segment of the media file (11a) is to be used to signal the occurrence of an event. Instead of storing the segment in the communication device (10), the offset selector application (11b) typically stores only offsets (21a 21b) in respect to the media file (11a), and the offsets are used in combination with the media file (11a) to provide the alert notification.