A leading development in the search for true spatial sound reproduction was shown by research house IRT and Sisvel Technology at the recent CeBIT show, writes Kevin Hilton. Binaural Room Synthesis (BRS) is designed to create the sound of a 5.1 room on headphones by tracking the movement of a listener's head. By logging the different positions of the head the BRS system is able to create the impression that a person is moving "acoustically" in a virtual room, with the sound sources appearing as fixed positions in the sound picture. BRS is the result of 10 years research by the IRT (Institut fuer Rundfunktechnik), which is based in Munich and works with leading broadcasters in Germany, Austria and Switzerland, including ARD, ZDF, DRadio, ORF and SRG/SSR. The work was carried out in cooperation with Sisvel Technology, the research, development, and technical consulting arm of intellectual property management specialist the Sisvel Group. The aim of the system is to reproduce good quality surround sound without the need for expensive hi-fi equipment and acoustic treatments. Multichannel audio signals are controlled by head-tracking data and combined with the results of modelled binaural impulses measured in a room with a 5.1 system. IRT claims this allows listeners to move their heads while wearing headphones and experience the same spatial effect as if they were in the original room. The position of a person's head does not affect the reproduction as the input signals are rendered to recreate the localisation of the virtual loudspeakers in relation to the set up of the original space. www.irt.dewww.sisveltechnology.com
The growing pains of surround sound
Tim Carroll has built a career on surround sound but he acknowledges that 5.1 is still in "the vast minority" on today's home entertainment scene. Kevin Hilton listens as the founder Linear Acoustic sounds off about the benefits of 5.1 but how stereo still has a place.