The science fiction reality
BBC tests '3D sound'
Gary Cornhouse;Digital Vision;Getty Images
Engineers at the BBC are currently beavering away designing new 3D audio technologies. Soon, we will be able to enjoy our favourite radio and TV programmes in glorious three-dimensional sound.
Great stuff! But what does it mean in practice? Surely, as hardened fans of The Archers might argue, radio is already capable of creating the illusion of 3D audio where, in shows such as radio plays, the brain fills in the blanks to produce images as vivid as TV.
What is 3D sound?
The BBC's technology division, BBC R&D, promises that its new 3D acoustics will be able to convince the listener that tunes and sounds are not only emanating from their radio set or television, but also from above and below them, according to a BBC white paper.
It's something that's already been tested, with the Beeb trying out the latest in 3D sound tech on recordings of the Last Night of the Proms, an Elbow gig from Abbey Road Studios and the Wizard of Oz radio play.
"This type of research is absolutely necessary," says CEO and chief designer at Tivoli Audio, Tom DeVesto. "Since the beginning of radio and sound reproduction in general the goal has always been to offer the listener 'convincing' sound. This is a next step."
Will I need a new radio or TV?
No. The BBC's 3D sound gurus claim that this new immersive audio will work fine on your current radio or TV speakers or headphones.
"We want to deliver a new experience to the audience that gives them more immersion and involvement in the content," explains the BBC's lead audio technologist Frank Melchior, stressing that no new radio or telly will be required for licence-payers to enjoy 3D sound.
"Sound quality is an important benefit of digital radio and further innovation will enhance the digital experience on all platforms," adds Laurence Harrison, from digital radio lobbyists DRUK. He agrees that this latest BBC research is important, "as consumers are already enjoying 3DTV and in the future will expect a similar experience on radio."
But how does it actually work?
What clever scientific tricks are the BBC's engineers using to convince our ears that stuff is happening all the way around us?
"Humans are set up to localise sound," explains Dr Nigel Holt, a psychologist from Bath Spa University who specialises in auditory psychophysics, the study of how humans perceive sound.
"Two ears means that we can accurately tell how far to the left or right a sound is.
"The shape of our ears with their folds and creases is not just for some kind of weird decoration. It is these folds that allow us to tell how high or low a sound is."
The 5.1 'surround sound' 3D audio reproduction that many of us are currently used to uses small speakers dotted around the room to 'con' us that sounds are moving around us.
But the BBC's project will use different techniques that don't rely on a room full of speakers. One such technology is called 'ambisonics' - where a recording is made using multiple microphones positioned in different places. By overlaying the soundtracks on top of one another, the listener hears the '3D' sound, which is more like actually being there.
Dr Holt explains that this illusion of 3D audio "can be very compelling, when done properly you can really can 'feel' as if you are listening in the place where the sound was recorded, which can be a very exciting and emotional experience."
So when can we hear it?
BBC press officers are currently keeping their cards close to their chest on this latest 3D audio research, but expect to find out a lot more about the Beeb's future broadcast plans later this year.
Of course, what any true music or theatre fan really wants is to hear live concerts and radio plays in which the entire sound experience (of a concert, radio play or the like) is able to be digitised and then accurately recreated in our homes.
"This advance, if it really is going to happen, is down to the fact that the way we can record and store sound is now better than it used to be," adds Dr Holt.
"Also, and importantly, our tellys, radios and computers now have a good deal of processing power on board to deal with the sound before it is sent out into our rooms."