Physical Factors*
John C. Steinberg, W. B. Snow · Bell System Technical Journal · 1934
In considering the physical factors affecting it, auditory perspective is defined in this paper as being reproduction which preserves the spatial relationships of the original sounds. Ideally, this would require an infinite number of separate microphone-to-speaker channels; practically, it is shown that good auditory perspective can be obtained with only 2 or 3 channels.