Radio
From Memory Alpha, the free Star Trek reference.
Radio is the name of a 20th century device which is used to transmit or receive sound or signals by means of electromagnetic waves. This name is also used to describe signals whom are transmitted on a specific bandwidth.
In an alternate timeline, communications officer Hoshi Sato analyzed radio signals from the planet Earth during 1944. One of a transmissions was a speech by Winston Churchill. (ENT: "Storm Front")
Subspace radio is an advanced radio system. (TOS: "The Cage")
In 2268, Uhura monitered several radio broadcasts on Sigma Iotia II and planet 892-IV. (TOS: "A Piece of the Action", "Bread and Circuses")
While star charting on the outer fringe of the Milky Way Galaxy in 2269, the USS Enterprise discovered a source of mysterious radio emissions originating from an insectoid pod ship trapped in orbit of the dead star Questar M-17. (TAS: "Beyond the Farthest Star")
