How the Radio Works
You hear music on the radio because of radio waves. The radio waves travel at 186,000 miles per second. All radio waves have an amplitude, a wavelength, and a frequency. Frequency is the number of waves that pass by per second. The waves carry sound because the transmissions have a combination of two different kinds of radio waves: audio frequency and radio frequency. Audio frequency waves represent the sounds that are being transmitted. Radio frequency is the waves that carry the audio information. An antenna picks up the waves from tons of different transmitters and turns the radio waves into electric signals. When you listen to a radio program you have to tune the radio to a certain channel, or carrier frequency. The frequency is converted to a lower level which is constant and never changes. Amplifiers make these signals stronger. The signals are separated by a demodulator and the sound signal can be made louder or softer with the volume control. A different amplifier strengthens the signal again and the loudspeaker turns it back into sound waves. That is why you hear what you hear on the radio. It is confusing so why dont you take a look at the diagram to clear things up.