5.1-channel surround sound in Digital Audio Broadcasting
(DAB) can now be played back with standard
stereo headphones - thanks to Ensonido, a new technology
of Fraunhofer Institute for Integrated Circuits IIS.
At High End 2005 in Munich, Bayern Digital Radio and
Fraunhofer IIS present for the first time multi-channel
sound for headphones in digital broadcasting.
So far, surround sound has been the domain of large
loudspeaker setups in living rooms or theaters. Ensonido
now provides nearly the same listening experience through
a portable receiver and stereo headphones. In order to play surround sound over stereo headphones an acoustic model simulates the natural transmission of multi-channel sound from loudspeakers to the human ear. Harald Popp, head of the Multimedia Realtime Systems department at Fraunhofer IIS: "Ensonido now offers the DAB audience surround sound with portable devices." The first live presentation of this technology takes place at High End 2005 at the booth of Bayern Digital Radio.
Multi-channel sound in DAB is achieved by the new "Spatial Audio Coding" technology (SAC). The Moving Pictures Expert Group (MPEG) is currently standardizing this technology as a multi-channel extension of existing perceptual audio codecs. Fraunhofer IIS significantly contributes to the standardization. The system is fully backward compatible and achieves an audio quality very close to a discrete multi-channel audio transmission. Unlike the latter, with SAC the data rate increases by just about 16 kBit/s for transmitting surround audio instead of stereo. In the upcoming MPEG standard the system will even work with spatial data rates as low as 5 kBit/s. Thus, SAC enables a smooth, compatible, and cost-effective introduction of multi-channel sound to DAB.
Information about DAB can be found on www.digitalradio.de/en.
For information on Ensonido please visit www.ensonido.com.