the weirdest experience I've had, which I've replicated a few times, is related to the sort of intermittent chirping sounds that I have as part of my T. One time I was laying in bed, motionless, and decided to start touching my index finger to my thumb in sync with the chirping. Every time I'd hear the chirp, I would touch my fingers.
After several minutes of this, I became aware of a feedback mechanism: initially, the chirps slightly preceded the finger touch sensation (because of the reaction time involved in hearing the sound and then making the movement). After a period of time, though, the touch seemed to be occuring more or less in perfect sync with the sound -- and then a few moments later, it seemed that the sounds were actually reacting to the touch sensation, and not the other way around!