In the beginning of the 1920s, AM radio was invented using a technique called ‘amplitude modulation’. Then about 30 years after the advent of the AM radio, FM radio, using a technique called ‘frequency modulation’, was introduced. Even after that, various inventions, such as tape and the Walkman were introduced and radio maintained its status as a main media known for sound quality. Accordingly, we could regard radio as one’s companion in every day life, as one of the media mediums that has to undergo many changes.

However, during the 1980s with digital-sound devices such as CD, DCC, MD spreading throughout the world, radio had to drop down from this highest of positions. Not only was the radio’s sound qualities degrading due to the increase in the number of high rise buildings, they also had to suffer competition with new media mediums such as the popular Internet and TV. Considering the fact that there was also a song called “Video killed the Radio Star” during the 1980s in England, it may not be too much to say that the advent of TV affected the fall of the radio the most.
However, the radio has revived itself during the past few decades, and is now thought of as a media containing both Analog and digital technologies. That is, radio stations are getting back the attentions of the public.