The beginning of my trip was excellent. We started at 9:00pm. Nice visuals, and lots enlightening thoughts. The sound didn't come until I tried to go to sleep at 2:00am. I don't normally notice it under normal conditions. However, with my eyes closed the sound was DEAFENING. Drove me nuts because I couldn't go to sleep. So rather than fight it, I got rid of the sound by thinking. Of course I couldn't go to sleep while I was thinking, but it was better than listening to the deafening roar of silence in my head.
My first thoughts were of the sound. I came to the following conclusions. I only heard it when my mind was blank. I have since labeled it the sound of silence. The sound also had a visual pattern which was interesting to look at. When I looked at it long enough, materials manifested in the pattern. I could see events unfolding, places, people, etc.
I think the mushrooms kept me awake with this sound, and the sound made me think. I haven't suffered from light episodes of insomnia since my childhood. But I believe that these periods of lying awake at night thinking did a lot for my development.