Radio waves and sound waves are different.

To see how your radio station sends sound your way, click through this animation.

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