MP3 creators Fraunhofer IIS, in association with Dolby Labs, LSI Corp., and Phillips Applied Technologies have announced the licensing terms for MPEG Surround, which promises to bring surround sound to audio streams without much overhead.

Fraunhofer has been pushing hard In an attempt to encourage the adoption and growth of MPEG Surround, what is internationally known as MPEG-D. Last week at the IFA consumer electronics show in Munich, Germany, Fraunhofer IIS showed off its partnership with Rockantenne digital radio station, which now streams in 5.1 surround using the technology.

MPEG Surround adds to any audio format a sidestream that contains spatial data, which re-creates surround sound in compatible devices and does not effect the stereo playback of those incompatible. Use of MPEG Surround with HE-AAC audio files effectively results in 5.1 surround at a bitrate of 64Kb per second or less, Fraunhofer said.

While not true discrete 5.1 surround, Fraunhofer says the achieved audio quality is "very close...despite the fact that the surround image is represented by a very low additional bitrate," which can be as small as 4 kbps.

Standardization of MPEG Surround was finalized last year, and today, the patent holders announced their worldwide joint licensing program and preliminary licensing fees for companies building products and software working with the format.

MPEG Surround should not to be confused with MP3 Surround, which Fraunhofer debuted nearly five years ago, and was recently included in Sony's PlayStation 3.

MP3 Surround has seen little uptake since its launch, but Fraunhofer hopes the flexibility of MPEG Surround will make it attractive to services such as Internet audio streams, digital radio and mobile television. The company says DAB in Europe and HD Radio in the United States could benefit from surround sound with little overhead. DAB has often been criticized for being worse than stereo FM analog stations.

Fraunhofer actually debuted MPEG Surround at the annual 3GSM conference in 2007, focusing on mobile devices such as cell phones. DVB-H or MediaFLO are two mobile TV standards that could be improved with surround sound even when using standard headphones.

"Specifically for portable applications, MPEG Surround offers a binaural mode, providing spatial rendering and reproduction of multi-channel audio on stereo headphones," the company says.