Thank you for posting these interesting notes about generating images in your mind. This of course lies at the heart of The vOICe approach where arbitrary image information is provided via sound, and it is left to the brain to try and learn to (re)synthesize the original visual view.
I wonder, given what you say about John's AGC, how well can you mentally "see" (visualize) a view such as in the sound file (direct URL to short wav sample follows, so set your media player to auto-repeat)
or the slowed down sample
Seeing with Sound - The vOICe http://www.seeingwithsound.com/intro.htm
John A. Gardner Professor and Director, Science Access Project Department of Physics Oregon State University Corvallis, OR 97331 tel: (541) 737 3278 FAX: (541) 737 1683 SAP URL: http://dots.physics.orst.edu/