A receiver of a telephone to hold near to one's ear.
The arm on a pair of glasses that hooks over the ear to hold them in place.
A speaker placed inside or held near to the ear.
A device that can transmit radio signals.
The technology that allows for the transmission of sound or other signals by modulation of electromagnetic waves.
A device that can capture (receive) the signal sent over radio waves and render the modulated signal as sound.
The continuous broadcasting of sound via the Internet in the style of traditional radio.
On-board entertainment system in a car, usually including a radio receiver as well as the capability to play audio from recorded media.
To order or assist (to a location), using telecommunications.
To use two-way radio to transmit (a message) (to another radio or other radio operator).