Ded_wards, I haven't searched MIT's archives lately, but I'm sure you'll find it under the Dept. of Physiological Psychology, ca. 1964-1966. The title of the paper is "Controlled Studies in Human Stereophonic Perception."
We had hundreds of volunteers (S-T-E-R-E-O was everywhere!), and more important, the first computer system large enough to crunch statistics and probability -- at the same time! So, no study of this type was even possible any time earlier.
Although my little project wasn't specifically concerned with re-producing virtual sonic environments using only two loudspeakers, in 1997, a fellow at MIT named Bill Gardner did his PhD thesis on that very subject. You can read it (150 pages) at:
http://sound.media.mit.edu/Papers/gardner_thesis.pdfFor those of you too busy to read it in detail, it describes a way for producing a "sweet spot" anywhere in the listening room through the use of a procedure called "head tracking." But it leaves no doubt that full re-creation of a sonic environment is possible using only two loudspeakers.
Thanks for the lively discussion ;--)
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