Fraunhofer and Telos to Show Surround System for HD Radio

Fraunhofer Labs says it has devised a way to transmit 5.1 audio to receivers using the data channel of Ibiquity Digital’s HD Radio service.
At the NAB Radio Show this week, Fraunhofer and Telos/Omnia will demonstrate live, over-the-air 5.1 surround. The companies consider this the first public demo of the new system; they performed private demos at the spring NAB.
In the system to be shown, 80 kilobits per second are used for the stereo channels and 16 kbps for the surround information. The system is based on work by Fraunhofer IIS and Agere Systems in the area of “binaural cue coding.”
According to the companies, three factors are required for the perception of a spatial audio image: level difference, time difference and coherence between channels. These values are represented as a function of frequency and time with compact coding and allow for a data savings compared to transmitting all audio channels individually, they stated.
Fraunhofer developed MP3 and MPEG-AAC. Executive Harald Popp said the company believes surround is the next major audio enhancement.
The surround technology can work with any core stereo codec. Fraunhofer IIS has presented it as an enhancement to MP3 and MPEG-4 HE-AAC and work is underway to marry it with other codecs.