The number of Americans that listen to radio at work is declining, as more and more people turn to Internet radio.

According to data from the Arbitron/Edison Media Research Internet & Multimedia series of studies, among people who are employed full or part time and listen to radio at work, the portion listening most often via the Internet has grown from 12% to 20% in one year’s time.

Even more ominous for traditional radio – educated listeners are among the first making this move.

The difference is particularly stark when looking at the data sectored by education. Among college graduates who listen to the radio at work, fully 30% are listening most often via the Internet, as compared to non-college graduates, among whom 12% listen most often online.

“The implications of this finding are clear,” says Larry Rosin, President of Edison Media Research. “For a growing number of people, obviously especially among those whose work is in front of a computer all day, the Internet is simply a better solution for ‘radio’ listening than a traditional AM/FM Radio.”

“Thus radio stations need to think about the quality of their streams, and promote their streams. After all, on the Internet, the competition is not just the other stations in town; instead the possibilities are essentially infinite.”

Traditional radio needs to look beyond Edison’s recommendations, too. Radio needs to understand its competition is not just the station across town or around the world, but it’s competing with the radio station that you’re creating with podcasts and playlists.