Tired of seeing its audience lured away by satellite radio, traditional radio stations are beginning to broadcast in high definition. “The hitch is that a special – and expensive – radio is needed to hear the new offerings, and a consumer would be hard-pressed to find such a radio in a store. The radios are available online, through hdradio.com. Undaunted, 12 of the nation’s top radio companies last week started a $200 million advertising campaign to tout HD radio in the first 28 markets where it has been launched.”