Btw I read an article online once linking diet and obesity to tinnitus.
It said kids are getting more tinnitus these days, but they are also fatter.
Necro-bump...was looking up what folks here when they are alone and in a quiet place...I hear a very faint hissing noise myself.
An interesting note: John Cage the experimental composer was profoundly influenced by an experience he had in an anechoic chamber.
An anechoic chamber is meant to be the most soundproof environment you can get. He was fascinated by silence and so arranged to get a session in one to experience "true" silence. While in the chamber he heard a faint rushing noise and wondered what it was. The technician informed him that the experience was common. In absolute silence, we can never achieve absolute silence. The rushing noise he heard was the sound of his own blood pumping through his veins.
We will never be able to achieve true silence in the physical realm.