Full spatial surround sound has been a 'nearly' technology for years. But, as Kevin Hilton reports, developments on show at September's IBC exhibition may point to it finally entering the mainstream
3D was the big thing at IBC 2008. You couldn't move for camera rigs and video displays specially designed for the deeper, immersive format. Stereoscopic imaging in TV has stalled since then and so had a much lower profile during this year's show but the 3D concept was kept alive as more audio developers presented different ways to recreate a true spatial sound experience.
In cinema world, Dolby Labs has is already there with Atmos. This object-based surround format – which delivers height and depth as well as length and width to a sound picture – is now being made available on Blu-ray Discs through extensions to the Dolby Digital Plus 7.1/5.1 technology that is standard to the delivery format.
The company's development of discrete-channel, more realistic surround sound began during the mid-1990s with AC-3 coding, the basis of the original Dolby Digital 5.1 system. During IBC 2014, Dolby demoed AC-4, which is not so much a successor to AC-3 as a way to deliver multichannel audio to provide additional features for both broadcasters and viewers.
AC-4 is also object-based and designed to help create "engaging and personalised sports programming" and support multiple languages, as well as provide "adaptive 360-degree audio experiences anywhere, on any device".
The personalisation element, explains Tarif Sayed, director of Broadcast Services for Dolby, is intended to go further than current channel-based 'red button' interactive services and use the many different streams offered by AC-4 to deliver alternative commentary and effects options.
"If I'm watching a sport like international hockey, I can choose the language of the broadcast commentary, or have a biased fan commentating with the sound of his team's supporters for background, or the comments of a coach, or just effects," Sayed says. He adds that hockey has been one of the test areas for AC-4, along with NASCAR and football. The technology was submitted to ETSI in May but no commercial installations have yet been confirmed.
Research into immersive audio was at one time being driven by the growth in 3D imagery. Now that is less of a consideration in broadcast – if not completely a dead duck – 4K/Ultra High Definition is seen as the obvious visual partner for any spatial sound system in TV. Japanese public broadcaster NHK has been at the forefront of R&D for 4K and now 8K transmission, with 22.2 sound the audio accompaniment. What is not widely known is that 22.2 is based on Fairlight's 3D Audio Workspace (3DAW).
Fairlight's chief technical officer, Tino Fibaek, explains that NHK defined what they wanted in terms of loudspeakers and some tools but that the Australian company developed the rest. A key component of 3DAW is the AirPan user interface, which enables sound elements to be manually placed in the soundscape using a Virtual Reality positioning controller.
Fibaek comments that soundtracks can be mixed in 3DAW or on audio workstations including Pro Tools and Nuendo. There is also the option to master finished projects in other immersive formats; as well as NHK 22.2 Dolby Atmos and DTS MDA are now part of the programme, while Auro-3D signed up during the week of IBC.
The target for the developer of any emerging technology is industry recognition through an international standard. The IBC Future Zone had demonstrations of EMCA-407, which is able to carry NHK 22.2 (demonstrated with 4K video on the broadcaster's own stand nearby) at 256kb a second over satellite links and 4K HEVC (high efficiency video coding). The technology was shown by France Télévisions, satellite operator SES and low bit-rate audio coding specialist Swissaudec, all three of which have been working in conjunction with IBC, ECMA International, video compression developer ATEME, Mayah Communications, 3D audio producer Tom Ammermann's New Audio Technology, EPF Lausanne and the Virtual Acoustics Technology lab at McGill University in Montreal.
Research institute Fraunhofer IDMT has been developing an immersive audio technology over the last few years and at IBC showed the latest additions to its work, an intuitive user interface. The SpatialSound system (pictured) range comprises two systems for different applications: Stage, which allows the sound to follow the movement of individual actors in a live performance; and Wave for "compact and efficient spatial sound reproduction in mobile or fixed installations". The new introduction is Control, an interface for both systems that allows PCs, tablets or smartphones to be used in the production and demonstration of immersive audio as well as live staging. A Fraunhofer spokesman said uses included planetariums, live shows and theatre work.
Spatial sound is a cinematic reality and theatre and live events are following suit. Whether broadcast also embraces it is less certain, particularly as uptake depends on transmission practicalities and the willingness of consumers to fill their living rooms with loudspeakers. But the potential is there...