Cox Radio has joined Clear Channel and Entercom in announcing plans to roll out HD Radio in markets across the United States. HD Radio brings digital CD audio quality to FM radio stations and FM audio quality to AM stations (but does little to improve the quality of most talk radio shows). The technology will also enable broadcasters to more easily provide additional content such as traffic updates, sports scores, and song information. HD Radio requires listeners to upgrade their radios to compatible radios, but HD Radio broadcasts and traditional analog radio broadcasts will coexist. Earlier this summer, the nation's largest broadcaster, Clear Channel, said that it would convert 1000 of its stations to digital broadcasting over the next 4 years, and the company plans to offer the technology in 95 percent of the top 100 markets within the next 3 years. Entercom will roll out HD Radio technology to 80 percent of its more than 100 AM and FM stations during the next 4 years. Cox's rollout will include an upgrade of 80 percent of its 78 AM and FM stations over the next 4 years, as well.