Pink Floyd's The Final Cut made use of a special encoding process that allows the simulation of "three-dimensional" sound, called holophonics. This was also adopted by Roger Waters for his Pro's and Cons album; while on Amused to Death, he used a somewhat similar mixing process called QSound.
"By the way, has anybody really noticed the 'huge improvement' in sound staging produced by Mr Zuccarelli and his labs? If so, explain what's so special.
I noticed it. It really does give a certain amout of imaging, around you rather than just between the speakers. When Waters did his Pros & Cons show on the radio in 1985, he did an introduction where he walked to a timpani, struck it with his fingernail, and then said "If I ask you to point where that timpani came from, [here I pointed over my right shoulder] and if you don't point over your right shoulder, then we're in trouble." It was impressive.
As for just what it is, they were very secretive. They had "ringo the holophonic microphone." The process was based on holography, but of an audio form (you can do holography with any wave-based phenomena). The theory was that there were high frequencies generated by the ear (and some people have been shown to 'generate' some frequencies from time to time), and that sounds interfere with these frequencies, and the interference pattern is what we interpret. So, what holophonics is is a conversion of sounds directly to that interference pattern.
Now, the fact that this sounds like a crock is immaterial, because it does work. So, just what is it? Most (including myself) believe it's just a form of binaural recording. That "ringo" is probably just a dummy head with microphones where the ears are. And when you listen with headphones, your ears are right where those microphones were, and you hear it as if you were actually there. Binaural is fantastic fun, and I wish more people would work with it. It's a shame, though, that Floyd/Waters got duped into believing that Zuccareli's process was anything special....
Roger's Amused to Death (and a number of albums from other artists) use the QSound mixing system. It essentially allows sound to be positioned anywhere within a half-sphere around the listener. Roger himself explains how it works in the following interview (from Rockline, Feb. 8, 1993):
It divides any signal into a left and right component...(so it works with any stereo system), and it introduces minute delays at different frequency levels into left and right components to make your brain think that the sound is coming, not from in front of you -- from the two speakers -- but from in any one of a number of other positions around you. But you have to be sitting right between the two speakers, I mean exactly -- to within like an inch or an inch and a half [on] either side of the central perpendicular axis. And it is an amazing effect...