Voice-tracking

Voice-tracking is a technique used by some radio stations in radio broadcasting to make an illusion of a live disc jockey or announcer sitting in the studios of the radio station when one is actually not in the station.
Background.
Voice-tracking refers to the process of a disc jockey prerecording the parts when they speak on the radio. It is then mixed with songs, commercials and other elements to make it sound like a live air shift. Voice-tracking is mostly used in radio stations, especially during the night, overnight, weekend, and holiday time periods. Most radio stations also use it as a way to save money instead of having disc jockeys around the clock.
Variations.
Sometimes, voice-tracking is done so that people can do other jobs. For example, a DJ may also have a job as a program director or general manager. Voice-tracking allows that person to record a three-hour shift in less than a half-hour, leaving him or her time to do office work. A popular live weekday morning radio host can record parts for a Saturday show, allowing him or her to be on the air six days a week without spending more time at the station. It is also helpful during holidays such as Christmas or Easter, when people are off spending time with their families.
Formatics.
Different radio stations want their DJs to speak only at certain times. Here is an example:
As an example, see the picture below:&lt;br&gt;
As one song ends, the next song begins. At this point, the DJ doesn't start talking until the second song starts and he stops at the point where the song's vocals start.