High Quality Content by WIKIPEDIA articles! AM broadcasting is the process of radio broadcasting using amplitude modulation. AM was the first method of impressing sound on a radio signal and is still widely used today. Commercial and public AM broadcasting is carried out in the medium wave band world wide, and on long wave and short wave bands also. Once AM was the only commerically important method for broadcast signal modulation. Today, it competes with FM broadcasting for mobile reception of music and speech, as well as with various digital modes distributed from terrestrial and satellite transmitters.