I first read about anechoic chambers in a story about John Cage. The idea of such a chamber is that the room is treated with giant foam wedges so sound is not reflected away from the walls at all, as such the air is still and does not carry any sound to your ears. In the Cage story he talks about how even in a silent room there is no silence. Your body make sounds that when the environment is quiet enough become audible! You can hear your blood!!  Either way though this seems like it would be a very eerie phenomenon. This video via Sythntopia shows the setup of an anechoic chamber and mentions how PEOPLE are said to GO INSANE if they spend too much time in one. Check it out!!