Radio and television announcers perform a variety of tasks on and off the air. They announce station program information, such as program schedules and station breaks for commercials, or public service information, and they introduce and close programs. Announcers read prepared scripts or make ad lib commentary on the air, as they present news, sports, the weather, time, and commercials. If a written script is required, they may do the research and writing. Announcers also interview guests and moderate panels or discussions. Some provide commentary for the audience during sporting events, at parades, and on other occasions. Announcers often are well known to radio and television audiences and may make promotional appearances and do remote broadcasts for their stations.

Announcers at smaller stations may cover all of these areas and tend to have more off-air duties as well. They may operate the control board, monitor the transmitter, sell commercial time to advertisers, keep a log of the station's daily programming, and produce advertisements and other recorded material. Advances in technology make it possible for announcers to do some work previously performed by editors and broadcast technicians. At many music stations, the announcer is simultaneously responsible both for announcing and for operating the control board, which is used to broadcast programming, commercials, and public-service announcements according to the station's schedule. Much of the recorded material that used to be on records or tape is now in the form of digital files on computers. Public radio and television announcers are involved in station fundraising efforts.

Changes in technology have led to more remote operation of stations. Several stations in different locations of the same region may be operated from one office. Some stations operate overnight without any staff, playing programming from a satellite feed or using programming that was recorded earlier, including segments from announcers.

Announcers frequently participate in community activities. Sports announcers, for example, may serve as masters of ceremonies at sports club banquets or may greet customers at openings of sporting goods stores.

Radio announcers who broadcast music often are called disc jockeys (DJs). Some DJs specialize in one kind of music, announcing selections as they air them. Most DJs do not select much of the music they play (although they often did so in the past); instead, they follow schedules of commercials, talk, and music provided to them by management. While on the air, DJs comment on the music, weather, and traffic. They may take requests from listeners, interview guests, and manage listener contests.

Some DJs announce and play music at clubs, dances, restaurants, and weddings. They often have their own equipment with which to play the music. Many are self-employed and rent their services out on a job-by-job basis.

Show hosts may specialize in a certain area of interest, such as politics, personal finance, sports, or health. They contribute to the preparation of the program's content, interview guests, and discuss issues with viewers, listeners, or the studio audience.

Public address system announcers provide information to the audience at sporting, performing arts, and other events.

Work environment. Announcers usually work in well-lighted, air-conditioned, soundproof studios. Announcers often work within tight schedules, which can be physically and mentally stressful. For many announcers, the intangible rewards—creative work, many personal contacts, and the satisfaction of becoming widely known—far outweigh the disadvantages of irregular and often unpredictable hours, work pressures, and disrupted personal lives.

The broadcast day is long for radio and TV stations—many are on the air 24 hours a day—so announcers can expect to work unusual hours. Many present early-morning shows, when most people are getting ready for work or commuting, while others do late-night programs. The shifts, however, may not be as varied as in the past because new technology is allowing stations to eliminate some of the overnight hours.