A room so quiet, no one can spend more than 45 minutes in it | Hacker News Reader

A room so quiet, no one can spend more than 45 minutes in it

timesherald.com

184 pointsjamessun90 comments

BTW, Ron Sauro at NWAA Labs (http://nwaalabs.com/ or http://nwaalabs.ipower.com/pictures1.html) was hoping to build a quieter chamber but his funding dried up. He built his acoustical testing facility at a nuclear plant that was constructed but never commissioned.

The original plan was to build a 50ft by 60ft by 55ft chamber, with about half of it being underground. Given the exterior noise level of around 20 dBA (the plant is located in the wilderness), the thick concrete walls of the facility, and some additional noise and structural isolation he might very well beat Orfield's record with a much larger chamber (meaning it will be anechoic down to a lower frequency). If he can get the funding.

If you're ever in the area, Ron is a friendly guy and he'll be happy to give you a tour (he's on LinkedIn).

Agreed, I feel fortunate to have NWAA so close. Good to see you on HN, Anechoic.

I've worked in one of these for a happy summer making measurements of acoustic diffuser panels. I quite enjoyed it. However, it looks that that room actually has a regular floor; mine didn't. You lowered your own suspended floor (metal grill tiles) onto scaffold poles to get into the room, then tore it all up as you left. Falling off the "floor" was a Really Bad Idea; those foam pyramids have got a steel spike up the middle for rigidity, and you'd be in deep trouble if you fell onto them from 6 feet up (especially as no-one was going to hear you scream).

There was a safety microphone wired to the door switch for this reason (which also meant it wasn't QUITE such a good idea to say rude things about people in there :-)

However, it looks that that room actually has a regular floor

Look carefully at the picture, he's not standing on a solid floor, he's standing on a wire frame over more absorbers. Their website has a better pic: http://www.orfieldlabs.com/Researchtour4.html

IOW, their chamber is (fully) anechoic, not just hemi-anechoic.

Yes, you're quite right; I thought that was a particularly ugly patterned carpet he was standing on. I think that says more about British carpets than anything else :)

Looks like their wire floor is a bit more permanent than the design I was using; my microphone was on a rotating boom that could be swept 360 degrees from outside, and my sample mounting was a pole down to the real floor, so we could have the absolute minimum of interference from the mountings.

Well apparently one can hear one's own circulatory and nervous system: http://theresonator.blogspot.com/2007/04/john-cage-visits-an...

> Cage entered the chamber expecting to hear silence, but as he wrote later, he "heard two sounds, one high and one low. When I described them to the engineer in charge, he informed me that the high one was my nervous system in operation, the low one my blood in circulation."

I can attest to this. We have an anechoic chamber here at Michigan State and I've also been in the testing chamber at EV (Electro-Voice). Hearing the blood in your head and ears is quite odd, but the disorientation from not being able to place yourself in space is even stranger.

After reading this article, I immediately started to see if I could find one nearby and found out about the one at Michigan State. Would it be possible for me to go there and sit inside for a bit to experience this, even though I'm not a MSU student?

Likewise, I'd like to try this... it seems cool as hell!

Hey all -- I can see if I can arrange something. The chamber is in the basement of the Communication Arts and Sciences building and I teach in the College--but I don't know who currently runs it. Let me send some emails and see what I can do.

Sure thing, I'd be up for a trip out there and maybe we can meet up and grab food/drinks afterwards.

Send me an email since you don't have one listed in your profile! agscala@gmail.com

I'd be very interested in coming along as well, if at all possible. I'm near Michigan State often, doing UX Design at TechSmith. Feel free to email me at bulletsvshumans@gmail.com .

If you are able to make this happen, it would be very interesting if you could get the visitors to write a short note before entering about what they expect, how well they think they'll handle the disorientation, etc. After they're done have them write a similar note about their experience and how reality matched up with their expectations.

For all of us that don't have access to such facilities, this kind of before/after diary might be very interesting.

If you have heart issues and you have a period with no heart beat, even just seconds, the feeling of sudden silence is striking. I think it's likely that people just aren't aware that they can hear their heart beat all the time. It might just be me though, but I suspect not as I mentioned how quiet everything went to a cardiologist who didn't seem surprised.

I'm sure many people could, starting with the Deaf. I'd certainly enjoy a break from the incessant yammering of humanity.

I'd certainly enjoy a break from the incessant yammering of humanity.

It's not just a break from humanity, it's a break from everything (including nature, which typically fills the void when humanity is absent).

If you haven't been in a very quiet space, it becomes disorienting very quickly. The quietest space I've been in has been <12 dBA (my measurement equipment only went that low so I couldn't get the true Lmin). At that level, I could hear the blood rushing through my ear. I have a minor case of tinnitus which is typically inaudible, but in that space it was like an alarm clock screaming into one ear. The other ear seemed to desperately find something to "lock" onto, so it was amplifying every little thing it could.

After about 15 minutes I wound up opening a window to let a little wind noise into the room. That raised noise levels up to about 19 dBA and was much more comfortable.

>>>I have a minor case of tinnitus which is typically inaudible, but in that space it was like an alarm clock screaming into one ear.

Ah, I was wondering about that. (Now scrolls up to delete question asked elsewhere.)

I have tinnitus as well. The idea of a totally quiet room gives me the creeps, I know I wouldn't be able to stand it for more than a few minutes.

You're sure? I don't understand deafness to mean not sensing any vibrations whatsoever.

I've been in an anechoic chamber and it's not so much the lack of sound but the intense visual shock. You're usually in a room with incredible depth levels, sharp angles and so on. It can induce a feeling of sea-sickness.

The absolute silence exacerbates the issue but it's not the only factor at play.

There was a small room like this at my university. It was fitted with a "panic" button, because if anything happened you in there, no one could hear you shouting.

I was hoping for more science-y details. Any HN folks care to give a better explanation of what's going on here?

The room is anechoic and insulated. Anechoic means that the walls are treated to absorb all the sound waves that hit them, and not reflect them back. (Typically, anechoic surfaces are soft and cannot support much weight, so [guess] there is probably a support system to put weight bearing platforms inside.) Insulated means that sounds from outside the room are not transmitted in. A lot of concrete can take care of the high frequencies, but low frequencies often require special suspensions to keep sounds from the earth out.

The most interesting thing is the measured extent of what they've produced.

I've been in a few before. They are used a lot for testing the RF properties of wireless products. They basically let nothing from the outside in, and allow for no reflection on the inside. Thus you can isolate the characteristics of your device from any other possible surrounding noise. I usually get a headache after being in one for awhile, but I always assumed that's because the pointy foam shit smells like fresh paint.

The term is used for both RF and Audio wave absorbing rooms, but in this case they are talking explicitly about a room that doesn't reflect Sound.

Wouldn't they be the same thing, just "tuned" to block out different frequency ranges? I'm guessing the tuning is based on the material and shape of the foam, and thickness and material of the walls? It's all waves.

Sound waves and radio waves are not the same thing.

They're not the same things, no, but they obey the same wave mechanics, and due to the difference in propagation velocity, their wavelengths are actually very close. A wavelength of 3 meters is about 100 MHz in the RF world, and 1 kHz in audio terms.

That's why an RF anechoic chamber looks a lot like an acoustical anechoic chamber, and often sounds like one too.

A wavelength of 3 meters is about 100 MHz in the RF world, and 1 kHz in audio terms.

An acoustic wavelength at STP is around 1ft/30cm, not 3m (which is closer to 100 Hz).

D'oh, you're right; I started punching calculator buttons with 1100 f/s and turned it into meters somehow.

Point stands, though.

It's all waves.

EM waves vs pressure waves, they're not the same thing (although the math is basically the same, just with different constants). Something that affects an EM wave won't necessarily affect a pressure wave - a Faraday cage for example will block EM waves but won't do anything to block sound waves.

EM waves are transverse (they oscillate perpendicular to their direction of motion) and sound waves are longitudinal (they oscillate in the same direction as they move).

There are some mathematical differences between transverse and longitudinal waves, so it's not just the same math with a different medium.

They are different physical phenomena. Sound is a pressure and is produced by compression and expansion of the (local) environment. RF or light is a self-sustaining electromagnetic wave (assuming we are not right next to the source [i.e. far-field]) produced by a time-variant electric field inducing a time-varying magnetic field, which induces a time-varying electric field, which induces ... All these induced fields end up supporting each other and propagating the wave.

While they are both considered waves, it is not frequency regimes that differentiate acoustic pressure waves and RF waves -- RF waves can be anywhere within the "audio" spectrum and beyond, and audio waves can be well into the ultrasonic range and into the UHF regime.

The idea of the anechoic chamber is the same (blocking all reflections), but it is not just as simple as tuning to different frequencies. They do however need to be designed for a specific frequency range.

I am not an expert on anechoic chamber design (or acoustic wave propagation for that matter), but an RF anechoic chamber is not the same as an acoustic anechoic chamber, although it will show some functionality as one. Does that make sense, or am I just confusing the conversation? It did when I started writing all this. :/

You're right; the RF anechoic chambers are designed to absorb differently. However because they still do that at least partly through thick walls and foam cones; RF chambers are also pretty damn quiet - with the 2 I used for CE mark testing, if you stood two people opposite sides of the chamber, and one spoke 'into the wall' you had trouble hearing them unless they deliberately raised their voice.

Neither of the RF chambers I used had the foam cones on the floor; just carbon tiles.

... and audio waves can be well into the ultrasonic range and into the UHF regime.

Theoretically, at sea level on earth, the mean free path of air molecules allows for 3.4 GHz. But attenuation is proportional to f^2 which results in an upper limit of 100MHz. You need a medium denser than air at sea level for higher frequencies.

I read that title and immediately thought. Challenge Accepted.

I want one to meditate in each morning.

Being completely deaf in one ear, I'm sure I could last 90 minutest at least. A cool article, but a bit sensationalist.

I like that your process for calculating how long you could last appears to consist of multiplying the amount of time others can last by their ratio of working ears to yours. Science!

As I read his comment I was going to write basically what you did, but I thought "No. No, that is too nerdy." So thank you =D

Relevant: I do wonder though if the disorientation would be less for someone with complete deafness in one ear. I would think that they are already somewhat used to the balance/orientation issues.

He mentioned that people generally can't be in there longer than 45 minutes. I would love to test that theory. Give me a desk, a laptop, and let me get to work.

The most interesting thing would be whether or not my tinnitus is going to drive me insane or not :P

In a room this quiet I assume using keyboard will sound very loud.

Quite the opposite - hence, 'quiet room'.

How do you hear your heartbeat if you can cannot hear your keyboard keys when pressed?

Because the veins are very near your ear canal. Any outside sound is not available, so the only sound you hear is those that are internal and wouldn't get very far anywhere else...

And I imagine even them are not louder, just that you're a lot more focused on them.

Not to mention the ventilator, the HDD, and the rest of the electronic components.

Here is a video of the effects in an anechoic chamber : http://channel9.msdn.com/Series/CampusTours/Microsoft-Campus...

We used to have one at HP. I hated going in there, supremely disorienting and creepy, especially with the weird panels on the walls.

I wonder how this would equate to being in space (preferably in a space suit) ?

I wonder what it sounds like in units of noise cancelling headphones.

I've been in the Orfield labs anechoic chamber. I didn't feel too disturbed, but then I never got the chance to be in there alone -- some friends and I went together.

Steve's a great guy. He'll give you a little tour of everything going on at Orfield labs, but the price of admission is a $20 check to a local food-bank.

He told my friends and I a lot of interesting things. Like how corporate offices use subtle noise from the air-ducts to drown out coworkers' conversations; or how casinos use echoing plates to project the sound of a jackpot across the entire gaming floor.

I definitely recommend paying it a visit if you ever find yourself in Minneapolis.

I would love to hear what my drum set sounds like in there. Has anyone ever practiced a musical instrument in a chamber like this? I wonder what the advantages and disadvantages would be.

Drums sound really strange without reverb. If you've ever drummed outside, the difference is really stark - I play outside with my samba band a lot, and all the drums sound really cold and quiet, so you end up playing a lot harder automatically just to get the sound of your drum to be as loud as you're used to. I imagine the anechoic chamber might be similar, with the added effect of not hearing any drum sound which would normally bounce off the floor - do, for example, you'd probably hear very little snare wire sound.

The reverb room actually sounds cooler:

> ...a reverberation chamber with bowed aluminum panels in which he sounds the same from 300 feet away as 3 feet away.

Reverb rooms are much easier to build (and more common) than very-quiet anechoic chambers.

Okay, but are perfectly diffuse rooms really more common than perfectly absorbent rooms?

Anyway, I didn't know that before today :)

Perfectly diffuse rooms are a common staple of acoustics labs in university and calibration facilities, it's a requirement for STC (sound transmission class) testing for building materials and wall/window assemblies.

Any acoustically well-designed movie theater (THX or HPS-4000 certified among others), performance space, concert hall or auditorium will be decently diffuse, at least at higher frequencies.

I enjoyed a similar experience sitting in the middle of a mile-on-a-side clearcut area on a windless, zero-degree Sunday in January in the far north. No planes, no traffic, no animal noises. I sat on a frozen log and listened to the blood in my ears for a half hour.

Give me a good book and I'll spend 45 hours in one.

Brilliant idea.. though probably bait'sy title... I would love to spend as much time as i can over there... If it's becoming annoying i can always sit down and start practicing vipassana(http://www.dhamma.org/) that would be fun to listen to only my body. :-P

The closest I think I've come to anything like this is a "soundproof" booth used for hearing tests. I remember that being eerily quiet (to listen for very quiet tones in headphones). Anyone know how this chamber compares to a hearing test booth? Sounds like it's probably quite a bit quieter...

I'm curious. If you speak in an anechoic chamber like this, what does it sound (or not) like?

There was an episode of 'Get Smart' where in order to keep the room quiet the words people spoke turned into word clouds. Eventually the room was so full they had to eat their words. This article reminded me of that.

I have tinnitus and I often wonder how I would feel in such an environment and what the whistling in my ears would sound like.

yes, noise is pollution. I would tax cars based on air and noise pollution and nothing else.

Why nothing else? How about congestion?

That's spatial pollution.

And [ugly car du jour] is aesthetic pollution.

I would tax buildings-activities for congestion. If you rent a building for residential use: no tax. If you rent it to be used as a Shopping Center: big tax. If on top of that, they don't have a big parking space: huge tax.

Big parking spaces just subsidies and encourage car use. (At least that's the line of the UK government, and the reason why they basically require you to have less parking spaces than household units in new residential developments.)

yes. That's why I said you will also be taxed if you attract traffic in a congested area.

I don't get why people can't spend more than 45 minutes in there.

I understand that you begin to hear your heartbeat and so on, but surely anyone who is even slightly deaf (e.g. even from just prolonged listening to loud music) wouldn't hear these very low-decibel sounds?

So it can't be the lack of sound, as a slightly hard of hearing person hears the noise floor drop out quite frequently. (Correct me if I'm wrong here; it's just my assumption). Is it that these sounds become so annoying, such a nuisance?

If someone had a noise-free keyboard (maybe touch) and were coding in there, would anything be a distraction? Would anything limit your stay?

I find sitting into a dead-silent room with a laptop (e.g. somewhere where you can't even hear a clock tick, nor any street sounds, nothing) to be completely maddening initially...but then after about 2-3 minutes you can immerse yourself and do something with extreme concentration.

The 45 minutes aspect is misleading. They haven't been using the room to test that, its just that no-one has spent longer than that so far.

Our title is (currently) "A room so quiet, no one can spend more than 45 minutes in it", and the Times Herald headline is even more specific: "A room so quiet no one can stand it for more than 45 minutes."

I'm wondering what it is they 'can't stand.' The article text is pretty vague. '“Your eyes don’t feel as comfortable in this room,” Orfield pointed out, adding that some visitors have had hallucinations during or after a spell in there. “You lose your touchstones.” Small wonder, then, that even Orfield spends no more than a half-hour at a time in the 99.99 percent soundproof anechoic chamber, and no one has lasted in there for more than 45 minutes.'

It doesn't match either my experience or my expectation, which is why I asked about it above. If someone had a silent computer to code on in there, could they crank out code for a couple of hours without nuisance, or would something bother them? If the latter, then what exactly would bother them?

> If someone had a silent computer to code on in there, could they crank out code for a couple of hours without nuisance, or would something bother them? If the latter, then what exactly would bother them?

First of all, I'm seriously disappointed I can't test this because no computer is quiet enough. Second of all, I can't stand working in sound-proofed rooms. I much prefer working in an environment with (non-distracting) ambient sounds.

Look, the "45 minutes" thing is total clickbait. I've been in an anechoic chamber and it is a little disconcerting and weird to suddenly find yourself hearing nothing at all. I only spent a few minutes in there, and it's not uncomfortable at first, but it feels good to get out. It's basically just a feeling of disorientation.

But I have no doubt that, properly motivated, you could easily spend an hour in there. Hell, if I had access to one I'd go do it right now just for dumb internet bragging rights.

I've been in an anechoic chamber ... and it's not uncomfortable at first, but it feels good to get out

Not all anechoic chambers are equal, and not all anechoic chambers are necessarily quiet - they're only as quiet as they need to be for whatever it's designed to test (an anechoic chamber designed to test ICE equipment might have background noise levels in the 40-50 dBA range), so be careful about extrapolating your experience to the quietest anechoic chamber in the world.

I think zipdog hit it on the head, and it's the PR-spin that turns it into seeming untested, unproven "no one can stand" bit.

Have they had open competitions? I feel relatively certain that people would endure in there effectively indefinitely: People can tolerate remarkable things.

I cannot speak to partial deafness, but I used to work in an anechoic chamber. It is indeed soul-suckingly disturbing after short periods of time. Even a totally "silent" environment has tremendous amounts of reverb and low-level reflected noise: you just filter it out automatically. In an anechoic chamber, this noise is gone, and your filter goes haywire. It starts filtering things that aren't there. You start hearing your own blood vessels in your eardrum, yes, but you also perceive a kind of disturbing anti-noise. It's very hard to describe.

Top it off with the fact that usually such rooms are entirely sealed off and that you're standing or sitting on a big mesh trampoline floating in the center of the room, and it all comes to one seriously creepy experience after about ten minutes.

How does it compare to using earplugs in a silent room?

I must assume it's quite different

Even though some of the sound travels through the facial bone structure (like when you hear your own voice) I guess most sounds come from outside

Also, earplugs add pressure to the ear canal so I guess this muffles somethings

How does it compare to an isolation tank?

In comparison, isolation tanks are extremely noisy.

You got to try an anechoic chamber to believe it. BTW: many universities have one. The one I worked at (BYU, long ago) has this one:

http://www.physics.byu.edu/research/acoustics/facilities.asp...

http://vimeo.com/15855229 (a corny advertisement, but shows the room well)

http://www.youtube.com/watch?v=0PGF_cGS8ts

It's a very good facility. Interestingly, I believe the main anechoic chamber used to be an echo chamber!

Thanks!

Huh, the vimeo one is weird. I'd think we wouldn't be able to hear them talk, let alone move boxes (at around the 1:00 mark).

Of course you can hear sounds: but you can only hear direct sounds. All reflected sounds are gone. And that's actually a high percentage of the sounds you normally hear.

An anechoic chamber is used to test acoustics in an environment with absolutely no reflection (reverb, echo, etc.).

Nobody tell the State Department - it'll be the new waterboarding.

Sensory deprivation has already been used as a form of torture by the US. See the case of Jose Padilla for instance.

Well, I've got access... I could take a book and go sit in our anechoic chamber for an hour, I guess. If I decide to try it, I'll report back.

And if you don't report back, we'll still have a data point..

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