Cohen has been a favorite of mine growing up, so.it pains me to say this, but he was apparently involved in some sort of MK experiments. Sensory deprivation for sure, there is a picture of it. Easy to find, just type in what it is. Maybe he was even some form of assassin doubling as a Bible-obsessed oversexed folk singer? Literally wouldn't surprise me one bit. There was only one article I ever saw on it I'll try to find it now. It was an interview or a book written about him by his neighbor or something, I don't exactly remember. Interesting read it you're into Cohen. Hang on...

http://lunamoth1.blogspot.com/2011/09/man-in-photo-taken-at-mcgill-university.html?m=1

(^ this is pretty fucking weird, gang and aforementioned picture inclusive.)