WHILE ACOUSTIC ENGINEERS HAVE BEEN TRYING TO BUILD THE PERFECT LOUDSPEAKER, A RESEARCH TEAM HAVE DISCOVERED THAT WE'RE LIVING UNDER IT. A REVOLUTIONARY SOUND BROADCAST WILL SOON USE THE ATMOSPHERE AS A LOUDSPEAKER.
THE WORLD OF music broadcasting is about to enter a new era. Ever expanding the horizons of music, technology is about to change its form irrevocably - never again will a radio or television transmission be regarded in the same light. Sound interesting? Sound revolutionary? It certainly should.
Let me explain a little more slowly: preparations have been made for a completely new kind of broadcasting - not just for music, but for any audio signal. The first experimental broadcast is due to take place on the morning of the first Sunday this month, and will take the form of a 30-minute music broadcast. The new system will take the form of satellite signals and use the higher reaches of the atmosphere and TV radio receiver dishes as transducers to convert the signals back into sound.
Let's go back five years to a small research team based in one of England's great universities. Three men and one woman - Professors David Lloyd, John Mortimer, Phillip Latton and Susan Edmunds - are conducting a research program intended to find out more about the upper reaches of the Earth's atmosphere when they discover that, if polarised by a particular kind of electromagnetic field, a layer only a couple of molecules thick can be turned into a rigid, transparent sheet. While further investigating this unexpected phenomenon they discover that, due to the curvature of the Earth, and hence its atmosphere, the sheet is the shape of a perfect loudspeaker cone. Not only that, but if the polarising signal is then modulated by an analogue signal in the audio range it will actually work as a loudspeaker.
Until now the project has been kept under the tightest possible security by the university in question, but they agreed to provide advance details to MT after news of the discovery was leaked to select areas of the hi-tech press. The university behind the project still wishes to remain anonymous for now, but research team leader David Lloyd confirmed details of the impending broadcast at a meeting only days before this article is due to appear in print.
"Yes it's true", he concedes, with the kind of gentle smile that only comes with years of patient disappointment spent in pursuit of science. At 57 years of age, Lloyd can claim that the "Skycast" is the culmination of all his research.
"There's still a lot of preparation to be made before the Skycast can take place, and there's far more work to do in finding out if it has any genuine use, if it's socially acceptable to fill the air with the music and so on. At present we've chosen to make the trial a program of light hymns to take place on a Sunday morning simply to make it as unobjectionable as possible, but it's certain to attract a lot of criticism."
Many of the theoretical details concerning the atmospheric phenomenon that looks likely to become known as the "Lloyd Effect" will not be made available even after the first broadcast, but Lloyd was happy to tell me what he could of the arrangements.
"The music signal will be transmitted to three satellites in orbit around the Earth", he explains. "They will be able to superimpose this on an unfocussed transmission over the United Kingdom and it is this that will cause the Lloyd Effect. But there are two major complications from there on. The first concerns the speed of sound in the rarefied atmosphere this high above the earth - in the thin air the sound will travel quickly and be transposed down in pitch as it encounters the thicker air lower in the atmosphere. For this reason we must first transpose the signal up for broadcasting and this is a rather imprecise science at this point. The second problem concerns the absorption of the sound by the atmosphere as it travels, and phase cancellations introduced by movements in the atmosphere - the lower frequencies will travel relatively undisturbed, but the higher ones would suffer severe and unpredictable phase cancellations and be almost completely attenuated by the time they reached the ground. Even if they were not, they would be disturbed in the same way as music at large open-air rock concerts: the sound tends to drift in the wind and easily becomes lost."
For this reason a second new principle will be tested on the inaugural Skycast broadcast.
"We're going to make use of all those unsightly TV dishes that Rupert Murdoch's Sky TV fiasco has spread around the country, and their owners won't even know it's going on", he chuckles. "We can split the signal into two - just like you would in the crossover in a domestic hi-fi system - and let the Lloyd effect provide our woofer and the TV dishes be our tweeters. In this way there's very little in the way of adverse atmospheric effects to account for. There will be anomalies of course; if you don't live near any TV dishes, all you'll be able to hear is the bass - a bit like sitting next to the bass organ pipes in church - and if you live near a concentration of TV dishes you may get high-frequency echo effects as the sound from successive dishes reaches you. These are the problems that cannot be overcome in an experimental broadcast.
"But if the system were to become widely accepted we could set up a network of high-frequency dishes across the country, or indeed the world, to give an even sound quality throughout. You see that's one of the beauties of it all - the Lloyd layer has no mass to speak of, in theory at least, it's a perfect loudspeaker."
PROFESSOR LLOYD AND his team may be well on their way to inventing the perfect loudspeaker system, but the world's human inhabitants have already made sure they've left him problems of their own.
"WE CAN SPLIT THE SIGNAL INTO TWO - JUST LIKE YOU WOULD IN THE CROSSOVER IN A DOMESTIC HI-FI SYSTEM - AND LET THE LLOYD EFFECT PROVIDE OUR WOOFER AND THE TV DISHES BE OUR TWEETERS."
"Over Britain, indeed over most of the globe, the Lloyd Effect should work perfectly, but there are problems over the poles. You see, the Effect relies very heavily on certain characteristics of the ozone layer to work, and where that layer is damaged or missing, it won't work properly. It's as if mankind's aerosol deodorants have poked little holes in my speakers', he muses sadly.
There are many ramifications to Professor Lloyd's work; some of these are theoretical, some are social. Theoretically, if there was enough gas in space we could use the atmosphere to make sound broadcasts to the stars - they'd take a long time to get there, but how would it be to hear the voices and music of an alien race?
More practically, how are people going to react to the idea of having the air full of music they're powerless to turn off? It's bad enough on the beach - this could be the turning point for the Noise Abatement Society. Lloyd, however, is too wrapped up in the possibilities of his proposals to dwell too long on the problems.
"Imagine..." he says, clutching at my sleeve. "Imagine a world where we could have music around us wherever we went. Imagine the music of the great classical composers, pure and undistorted, greeting you as you set out for work...*
"What about the advertising potential?", I venture. "Don't you think there's a danger that less idealistic people could use your discovery to bombard us with radio commercials?"
"That's just one of the reasons the details of my research are being kept so quiet", he replies.
"Even the satellite people making the test transmission will only know what they need to know. At the moment my team are the only people in the world with this knowledge - we could inflict our musical tastes upon you!
"No, no. I can see many benefits of establishing such a system - therapeutic benefits, recreational benefits, educational benefits... The effect can be regionalised so that different transmissions could be made to different geographical areas with bands of separation between them. This would take care of differing regional requirements whether they were international or quite local. With a sufficiently sophisticated system, I've no doubt we could even isolate individual properties and beam down a different music program to every garden in the world. It would be expensive, of course, but possible."
I contacted various governmental departments in an attempt to establish what their policies would be on such a system if it were to exist. It's remarkable how closed-minded people in authority can be to technical developments that are only just around the corner. The only conclusion I can draw from my research at this point is that their reaction is unlikely to be a sympathetic one, regardless of the technical merit of the achievement.
So. if you're not doing anything at 11.30 on the first Sunday in April, go out into the street and listen to what you might call the first broadcast of real World Music. It may be a once-in-a-lifetime opportunity.