On the level

Broadcast audio is always the bridesmaid and never the bride as video technology – especially HD – steals the limelight. Digital Broadcast looks to address the balance with a look at two of the biggest audio issues facing the industry: loudness control and the roll-out of surround sound services.

While all the hype and attention has firmly encircled the transition to HD pictures there is another component of this upgrade worth making a noise about - the transition to surround sound audio.
Although it is not a prerequisite of the HD shift, broadcasters are finding that surround sound is increasingly important to consumers.

“Sound without pictures is radio, pictures without sound is wallpaper,” says Niall Feldman, director of new products, SSL. “We find that successful content creators and broadcasters are very serious about audio. There is also growing consumer demand for better sound and separate audio systems for TV. One facet of the drive to make wafer-thin, wall-hung TVs is that the resonant cavities that surrounded bulky CRTs have gone. Modern thinner, flatter displays have increasingly poor audio as a result. To reproduce sound quality good enough to bring life to the picture, demands a separate audio system. Many of these are 5.1 capable, either through separate speakers, or creative ‘directional’ sound solutions.”

This pattern of increasing consumer demand is also being witnessed by audio signal processing developer, Dolby.

“It’s an exciting time for us. Audio is becoming far more prominent than it ever has been before,” says James Caselton, broadcast marketing manager EMEA, Dolby Laboratories.

“It’s not really a question of whether people want 5.1. Our concern now is about how we can help broadcasters and operators deliver it to their audiences,” adds Caselton.

“When stereo came along consumers thought it was great. Then we went into the iPod age and the focus was firmly on compression. Now what we are seeing is that emphasis coming back to the question of quality.”

In addition to offering consumers an improved experience, SSL’s Feldman also believes there is a solid commercial case behind surround sound.

“Content with HD pictures and high quality surround sound is an investment that should be viewed as having long-term return by content creators. Charging for added-value content is a growing part of broadcast economics as straightforward display advertising models are a less significant source of revenue,” he says.

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“In many ways the audio challenges for broadcasters are far simpler and more straightforward than those of video. Relatively, audio data rates are lower, the variety of options for storage and transmission are fewer and many of the challenges have been resolved. This means there should be no excuses for not getting audio ‘right’,” claims Feldman.

Orbit Showtime’s VP of broadcast operations and technology, Mike Whitaker, is not so sure that surround sound is quite as straightforward.

“We all know how to edit in stereo and work with multiple audio tracks and in multiple languages but if you’re doing compliance work or editing in Dolby, it’s an entirely different ball game,” says Whittaker. “The video for HD hasn’t changed an awful lot. It’s still colour, it’s still widescreen, there are just more lines. In Dolby its not just that there were two tracks and now there are six, there is all the meta data that is involved, the synchronisation and the loudness control. It’s very different and people are still learning.

“The broadcasters in Europe that have already transitioned to HD are telling us that the pictures are fine and it is the surround sound that must really be focused on. It has been the one thing that has caused the most headaches,” says Whittaker.

Whittaker is confident it is worth the effort.

“HD is a cinematic experience and it’s about putting viewers in the middle of the action. We are building up our HD capabilities at the moment in terms of what we can broadcast in terms of the broadcast transmission head end and we are very much looking at using Dolby. We are aiming to rollout our next generation set top box some time this year and it will be Dolby capable,” he reveals.

Whittaker also believes that the production process for surround sound requires an entirely new approach.

“Just as shooting in HD is not just about changing the camera you use. The extra lines mean you need to think about things like set design. Dolby is about sound design. It’s a totally different way to work and it requires some serious post production work,” he adds.