Labels:text | screenshot | font OCR: RADIO WAVES MICROPHONE ANTENNA OSCILLATOR AMPLIFIER - RADIO BEAM SOUND SIGNAL TRANSMITTER RADIO DETECTOR LOUDSPEAKER A sound signal can be sent through the air in the form of radio waves. The electrical signal from a microphone modulates a radio wave, produced by a device called an oscillator. When the resulting wave hits an antenna, it produces an electric current. A detector recovers the electric sound signal and a loudspeaker produces a copy of the original sound.