In meditation, one attempts to shut out external impressions in order to access the world within... well, sensory deprivation really helps. There's something called the Ganzfeld Effect where people can go into hallucinatory states if staring into a formless field of uniform color for several minutes. That's the idea behind sensory deprivation chambers or old-time techniques like mirror or psychomanteum scrying where the trance induced is required to "see" things.
Anyway, for people experimenting with brainwave synchronization through audio files, the Ganzfeld technique of putting something over your eyes to create the uniform field of vision might enhance the process.
http://www.web-us.com/ganzfeld.htm
Cut a ping pong ball in half and put it over your eyes while reclining or lying down. If the ball has a logo, then use two and keep the blank halves. To make it fit better, squeeze the circular half into an oval and smoothly trim down the longer sides of the oval. Upon releasing the trimmed part assumes a curve that follows the contour of your eyelids. Then you can color it red, blue, or violet with a marker or just keep it white and use a lightsource of your choice. Put on your favorite audio (simplest would be white or pink noise) and gaze off into the formless void... if nothing else, your visualization ability will become quite vivid after several minutes.
Applications:
* retrieving memories, recapitulation
* working out abstract concepts
* observing your thoughts and the inner world
* visualization exercises
* mind awake, body asleep
* remote viewing, scrying
* training open-eye trance-at-will ability
Acquiring fringe knowledge is like digging for diamonds in a mine field.
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