Archived from groups: rec.audio.pro (
More info?)
gmc wrote:
> I have heard that spending time in an anechoic chamber can be a very
> disorientating experience - tales of people only being able to spend
> eg 10 mins in that environment before having to get out & reorientate
> themselves.
I haven't tried this myself (but I would like to), but F.Alton Everest
reports in his book "Master Handbook of Acoustics" (Fourth Edition) in
chapter 3 in the section entitled "Sensitivity of the Ear" the following...
"The delicate and sensitive nature of our hearing can be
underscored dramatically by a little experiment. A bulky
door of an anechoic chamber is slowly opened, revealing
extremely thick walls, and three-foot wedges of glass fibre,
points inward, lining all walls, ceiling, and what could be
called the floor, except that you walk on an open steel
grillwork.
"A chair is brought in, and you sit down. This experiment
takes time, and as a result of your prior briefing, you
lean back, patiently counting the glass fibre wedges to pass
the time. It is very eerie in here. The sea of sound and
noise of life and activity in which we are normally
immersed and of which we are ordinarily scarcely conscious
is now conspicuous by its absence.
"The silence presses down on you in the tomblike room; 10
minutes, then half an hour pass. New sounds are discovered,
sounds that come from within your own body. First, the loud
pounding of your own heart, still recovering from the novelty
of the situation. An hour goes by. The blood coursing
through the vessels becomes audible. At last, if your ears
are keen, your patience is rewarded by a strange hissing
sound between the "ker-bumps" of your heart and the slushing
of blood. What is it? It is the sound of air molecules
pounding against your eardrums. The eardrum motion resulting
from that hissing sound is unbelievably small – only 1/100th
of a millionth of a centimetre – or 1/10th the diameter of a
hydrogen molecule!"
I'm not entirely sure that single oxygen or nitrogen molecules have
enough momentum to stimulate the mechanical apparatus of the middle ear.
Nonetheless, I would like to hear this effect for myself. Personally,
I think the observed phenomenon is more likely to be some sort of neural
background noise similar to amplifier hiss.
Anyway, you'll have to spend a good deal more than 10 minutes in an
anechoic chamber to observe this.
Chris W
--
The voice of ignorance speaks loud and long,
but the words of the wise are quiet and few.
--