In 2012 I spent 5 weeks-ish (I wasn't keeping track) in the forest alone in Siberia.
I remember at one point, after several weeks had passed, I wondered into a particularly beautiful part of the woods and exclaimed out loud "Wow!!"
It struck me that it was the first time I had heard my own voice in several weeks - with noone to talk to and no camera to interact with I hadn't made a sound the whole time! (Though my thoughts had been as active and deep as ever!)