Blackwell Reference Online

Extract

Radio is a media technology that permits one person or organization to communicate with many receivers over large distances via the electromagnetic spectrum and radiated electrons. Listening to radio is possible by modulating voice (→  Broadcast Talk ) or music (→  Popular Music ) onto a radio wave that transmits at a predetermined signal. A radio receiver is tuned to the modulated carrier wave broadcasting at that frequency and the radio circuitry amplifies the voice or music, after discarding the carrier frequency wave (→  Radio Technology ; Information and Communication Technology, Development of ). Radio is a ubiquitous and inexpensive means of mass communication. Audiences need not be literate, making radio accessible to everyone with the most basic language skills, or in the case of music, no language at all (→  Exposure to Radio ). Depending on the characteristics of the radio frequency, programs can be heard around the world (→  International Radio ), but are typically limited to a small geographic area. The device that became known as the radio took its name from radio waves, the band of frequencies that made the technology possible. Before that, it was more commonly known as “the wireless” because it operated without a physical connection. Radio was demonstrated by Guglielmo Marconi in 1895, in work based on the earlier theory of Heinrich Hertz and ideas by Nikola Tesla. ... log in or subscribe to read full text