Thanks to Sean Zimmerman, who I met at Conflikt, I got to go poke around at and in Microsoft’s anechoic chambers! One of them just recently set the world record for the quietest place on earth. And it was really cool.
The Building. Massive. Brutalist. Stoic. Waiting. Quiet.
Sean and Christian, Our Tour Guides
These rooms are called “anechoic chambers” because they are rooms that don’t echo sound. (An-echo-ic: An – negation, “echo” – echos, “ic” – characteristics thereof.) All normal rooms echo sound all over the place, as I’ve talked quite a bit about previously. These… pretty much entirely don’t.
Microsoft actually built four of these chambers, at different sizes, for different purposes. Two are tiny – far too small to walk into. Those are for various kinds of small device testing. But the two we’re looking at today are both much larger.
The first one, which I’ll call the Green Room, has a really big door!
Not that door, you clowns, the other one!
Yeah, this one!
It also has a metal grate floor which brings the noise level up a bit. It’s like -8db from 0 reference, which doesn’t give you much of an idea of scale – but for pretty much everyone, 0db is completely inaudible. Anything below that starts getting crazy, and the lack of sound reflection will start freaking some people out. Sound just kind of …collapses. It dies around you. That’s the territory we’re in, and we aren’t even in the world record room yet!
The absolute minimum for sound in this measurement scale is brownian motion in air – the sounds produced by random collisions of gas molecules. That’s -23db, and more or less the absolute zero of sound in a standard atmosphere.
The Green Room is neon green on the outside. It needed painting for protective purposes, but nobody specified a colour, so when this chamber started going up they asked the contractor ‘why this neon green,’ and the contractors were all ‘you got something against the Seahawks?’ XD
Green Room connects to the building HVAC, but has its own control zone and is baffled heavily inside – which means it can be completely cut off from building HVAC when in use. From memory, I think it completely blocks out everything external below 180Hz, and almost everything below that as well. That may and may not sound super-impressive if you don’t know how this works, but trust me – it’s impressive.
This is an 80s Doctor Who set, right? Quickly, Tegan – this way!
But this isn’t even the big story. The bigger chamber you haven’t seen yet? That one holds the world record. It certified at -20db for the Guinness Book. When people talk about Microsoft’s Anechoic Chamber, they mean the bigger one.
The record holder is basically a separate isolated building. It’s completely surrounded by the large cement building pictured up top, including overhead, and has its own separate HVAC system. There’s a gap of about a metre between the two structures. The only common point is the ground on which the two buildings rest, and the power and sound cables, which are, themselves, sound-insulated nine ways to hell and back.
Mind the gap:
Looks like a Vault-Tec utilities corridor. Supermutants, probably. Careful.
This – okay, few people remember this, but there was a time when home audiophiles of the particularly batshit sort would do this sort of thing for their turntables. No, seriously, they’d cut a hole in the floor of their house, and pour a cement base and column, onto which they would mount the turntable, for complete isolation. And as goofy as that is in a home audio environment – I mean seriously, what? – it is meaningful here.
Anyway. The floor in the big chamber is just fun to walk on. It’s a coarse square mesh that feels like walking on a trampoline. Bouncie bouncie! Obviously, this is a flats-only room, no heels here:
Below that is a super-thin fine mesh which catches dropped objects, and below that, more of the same sound baffling as used on the walls. Then – in all directions but down – the aforementioned gap separating the two buildings.
The Microsoft audio-testing crew want to put a tentacle in the gap space, or at very least an inflatable alligator. (This came out after I said that in Fallout 3, that gap would have water in it. And ghouls.)
Both walk-in chambers use special lighting. I don’t know the technical details, but they’re designed so what incredibly tiny amounts of noise they might make is at 40,000Hz, well outside human hearing. This to avoid the 60Hz hum of many light bulbs – even incandescent. I don’t know if they’re supplying DC power or very high frequency AC or whether that’s possibly a trade secret. Could be!
Quietest photon cannons on the planet
Oh, wait, you didn’t know light bulbs made noise? Surprise! When lighting out my studio I went through several different bulbs, testing for quietness. I didn’t go to the extremes shown here, of course, but still.
I did the same for my computer monitors, which is one of the reasons why I’m afraid to upgrade my digital audio workstation to widescreen – I don’t know what kind of noise profile the new ones might have, and going to a store will not help. Everything below air horn sounds quiet at Best Buy.
This room, like the green one, also has a Really Big Door. This one opens inward, instead of outward, which creates a problem – and check out how the back of this door interfaces with the wall it has to open into as a result. It’s pretty cool.
That interfacing is important; those wedge panels are interlinked. Damage one, and you have to disassemble all the way back to the door to replace it. Bill Gates once sent a memo to Microsoft Security saying, “Yes, the developers are allowed to play golf in the halls,” but that would not apply here.
That door – and the walls, and everything else, of course – mean that all sound above 150Hz is blocked completely out of the room, as is damn near everything below that. Then the wall treatment takes care of anything generated inside. And the microphones and mic preamp combinations they use for testing cost like $10,000 each – well more than my entire studio!
I’d like to say that I fruck out a bit when they let me stand in there in the dark and in quiet, but really, I didn’t. I found it calming and nice. They only kept the doors closed and lights off for four or five minutes; they say people can get pretty antsy in that short a period of time, but I was still rather enjoying it. To me, it sounded like a very quiet studio, just… lots more so.
I’d’ve liked a couch or something to lay down on. And would no doubt have fallen asleep almost instantly. No Sith Lord would have anything on me!
Meditate on this, Darth Asthma
Relatedly, Minion Paul doesn’t like being in my studio for long, because even that is too quiet and it freaks him out. So there you are. 😀
All in all: super-cool experience, and I can 100% legit say I have stood in the quietest place on Earth. Pretty awesome day. Thanks again, Sean! And as always, larger versions of the pictures are on Flickr.