Does being in an anechoic chamber cause hallucinations? According to several blogs (that likely copy each other), it does. The Orfield Laboratory in Minneapolis–Saint Paul, Minnesota, United States is reported to be the quietest room in the world with a rating of -9.4 dB sound pressure level (SPL). Several sources on the internet claim that this causes hallucinations and that nobody can stay there for long. It seems the blogs just copy each other. A selection:
Apparently it's so quiet, staying in there for a time will drive you insane. Nobody has been able to be in the room for more than forty five minutes.
Even Mr. Oldfield, the owner of the sound chamber, admits that he can stay in the room for no more than 30 minutes. The sound of his heart valve drives him crazy.
Geekslop goes on to quote Mr. Oldfield, but do not provide any real citation.
From an article in TCB Magazine, Patricia Kelly, September 2008:
With no reverberation in the room, you have no spatial orientation cues. After about half an hour in the dark, you can become disoriented. Eventually, you might experience visual and aural hallucinations.
The quiet chamber amplifies even the slightest noise, making people accurately aware of anything, including the sound of their heart beating. In fact, the sensation is so intense -- including the possibility of hallucinations -- that no one has been able to stay in the room longer than 45 minutes, according to the Deccan Chronicle.
This news has a link to the Deccan Chronicle which is now dead.
Is there any evidence for those claims? Does being in such a quiet room cause hallucinations, to such a degree that nobody is able to be there for long?