Satellite radio has the edge over HD Radio. It's been available longer, and it had a huge marketing push across multiple types of media since its inception. Still, some headway has been made in the broadcaster rollout and consumer acceptance of HD Radio over the past two years.

In January, Parks Associates released a report that predicts that 30 million households will have some form of HD Radio receiver in use by 2012. That same report predicts that satellite radio will be in 39 million homes by that same time. While not at an equal step with satellite, the prediction puts the two forms of digital radio at the closest they have ever been.

The report, titled Music to Consumers' Ears: Next Generation Radio, plots a steady increase for both forms of radio over the next five years. HD Radio shows the bigger prediction leaps. The figures nearly double in 2008 and 2009.

The study also identifies listening habits between the two services, saying that satellite users tend to use the service in mobile settings, while HD Radio users favor HD Radio listening in the home.

Source: Parks Associates Music to Consumers' Ears: Next Generation Radio, www.parksassociates.com