Sony Corp. announced it will sell HD digital radio players in July, making it one of the largest manufacturers to back the radio's industry's next-generation broadcast technology.

Sony said it would begin shipping a tabletop radio and a model for cars, the first step in what they say is a long-term commitment to the technology.

HD digital radio is a relatively new form of radio broadcasting that allows conventional radio stations to bundle multiple digital signals with their traditional analog signal and send it on the same frequency.

The digital signal —carried as a series ofones and zeros —provides crisper near CD-quality sound and allows for text and other digital information to be carried with the audio. Satellite radio also sends its signals digitally.

Unlike satellite radio, which is a subscription-based service, the content on HD radio is free.Consumers do needtopurchase aspecial radio receiver to pick up the digital signal.

According to the U.S.-based HD Digital Radio Alliance, more than 1,200 radio stations in the United States have adopted the technology and projects that more than 1.5 million HD radio devices will be sold in 2007.

The technology faces stiff competition, as consumers today have a wide variety of digital media options, particularly with portable media players such as Apple Inc.'s iPod.

"Digital terrestrial radio is the last frontier in audio," said Andrew Sivori, a senior product marketing manager at Sony's personal audio division. "And it's coming to price points that are becoming more reasonable for consumers."

Sony said the XDR-S3HD tabletop model will be available for about $200 US and the XT-100HD tuner will sell for about $100 US.

With files from the Associated Press