Sammy.Tao@SPEECH1.CS.CMU.EDU (02/13/91)
The explanation of why different people, or the same person using different equipment, or the same person on different days, perceive qualitative differences in Q-Sound is psychoacoustically reasonable. (Sorry, I'm in a hurry and can't find better words to describe it.) The reason is as follows: Q-Sound works partially on the manipulation of phase differences in sounds, which is one cue people use to lateralize sounds. (The other cues are time and intensity differences.) Experiments have shown that people have trouble lateralizing 180 degree phase shifts. Sometimes they perceive a single image; other times they perceive one image at the left ear and another one at the right ear. Since this a psychophysical effect, the results could vary between different subjects, different audio eqpt. used to reproduce the music (Maybe better components preserve phase relationships better?), etc. [Going back to nerd lingo, you'd say that interaural phase shifts of 180 degrees can produce perceptions of a single fused image or dichotic images.] I have _The Immaculate Collection_, and I perceived a 'wall of sound' that's been described before. It was like looking into a fisheye lens, but with my ears :^). It produced a different effect, but I wouldn't want it on all music. Sammy +-----------------------------------------------------------------------+ |Sammy Tao, Dept of ECE |email: Sammy.Tao@speech1.cs.cmu.edu| ^G if | |Carnegie Mellon University|NeXT mail: tao@fechner.cs.cmu.edu | I'm an | |Pittsburgh, PA 15213 |"A straight mentirosa..." | Aggie! | +-----------------------------------------------------------------------+