Updated

HD, for high-definition, seems to be all around us these days. High-definition television is de rigueur for the avid football fan or the nature lover who wants a crystal-clear picture on the tube. Already a battle reminiscent of the VHS-Betamax wars is brewing over different high-definition DVD formats.

But there's another HD that's scarcely been noticed by consumers, and perhaps for good reason. High-definition radio is the new kid on the block and proprietors of AM-FM radio stations are hoping they can use it to fight off strong competition from satellite radio and the Internet.

In HD radio, digital signals are broadcast along with the traditional analog ones. The listener gets far better reception and improved sound quality. As a bonus, the technology allows more signals to be transmitted in the same range of frequencies, so stations can actually add extra channels.

As with satellite, you get information about the program you're listening to and extras like local traffic and weather data. Unlike satellite, HD radio is free, no subscription required. So why haven't you heard of it yet?

Well, most radios don't come equipped with HD receivers and the ones that do are still expensive. Expect to pay $250 or more for an HD radio while satellite receivers can cost as little as $50 plus $13 a month for service.

Many radio stations are already broadcasting in HD, and more are promising to get on board in the future. Still, satellite offers more choices since you're not confined to what's local.

It's a given that someday soon nearly every radio, Walkman or home stereo you buy will come HD-ready and prices are already dropping. But with satellite radio and downloadable Internet podcasts gaining ground fast, HD radio has a lot of catching up to do.

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