A sound wave is produced with a frequency of 5 Hz - 20 kHz.
The sound wave is equivalent to a pressure wave traveling through the
A microphone converts the sound wave into an electrical signal.
The electrical wave traveling through the microphone wire is analogous to the original sound wave.
The electrical wave is used to encode or modulate a high-frequency "carrier" radio wave. The carrier wave itself does not include any of the sound information until it has been modulated.
The carrier wave can either be amplitude modulated (AM, top) by the electrical signal, or frequency modulated (FM, bottom).
The signal is transmitted by a radio broadcast tower.
Your radio contains an antennato detect the transmitted signal, a tuner to pick out the desired frequency, a demodulator to extract the original sound wave from the transmitted signal, and an amplifier which sends the signal to the speakers. The speakers convert the electrical signal into physical vibrations (sound).
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