The Quietest Room on Earth

so the reference for 0db is basically what they consider the threshold for human hearing which is 20 micro Pascal and this room is quieter than the threshold of human hearing hi my name is Mary spender and you are watching choose TED Talks and in this episode I with a few people you might recognize visit an anechoic chamber firstly what is an anechoic chamber it's a completely soundproof room designed to absorb any reflections echoes and resonances that cause any reverberation sure have a few built in their headquarters so that at any time they can test their microphones in a completely isolated and controlled environment oh it's also rumored that if you spend too long in there with the lights off you will go insane spoiler we had to try that out here we are in the anechoic chamber it's crazy awkward silences are much more real yeah Sciences are way more awkward near no reverb to help those out do you feel like it's you feel the air around your head or something like there's a pressure at the sensation of being underwater yeah yeah yeah when you're like submerged my voice is right here Mike yeah get the reflection off your hand I was skeptical about it and it's gonna be impossible to communicate through the camera what it's like to be in here but yeah just trust us it is really odd I feel anyway like the air is a physical thing around me like there's some kind of pressure that's weird clap without any reverb or it sounds like I'm hearing a clap after it's gone through like a noise gate yeah you know or the clap but with a really heavy noise gate on it it's weird yeah it sounded the same I mean obviously to me yeah yeah yeah is there a big difference so there's this phenomenon called the inverse-square law where sound as you get further away will have in volume when you've doubled the distance that you are so if I keep talking at hopefully relatively the same level it'll probably sound something like that through the camera and you don't get to experience this ever in the real world because you always have something that the sound is bouncing off of and you know reinforcing those waves in your ears but here it's it's pretty trippy you just the volume drops out Wow I've been wanting to do this for a really really long time having worked for sure microphones I knew that they had anechoic chambers built in their headquarters in Niles Illinois and of all the people I wanted to take in there of course it was Rob Andrew and Jeff they are massive nerds just like me and it's a pretty rare experience to be able to go into an anechoic chamber especially with some people who really know what they're talking about we always hype up the gym very much too so we'll be like alright welcome to the anechoic chamber we have a bot with the door closed we have about thirty seconds of air so I'm gonna talk really fast and this is where we you always see people like wait it's serious I should just sit here with my hand on the door as I do it the whole time and just seal people in maybe like so we do a lot of testing here 28 29 and this is where we do a lot of so we've been yelling in here we've been clapping in here now Mary's gonna play guitar I probably shouldn't turn my head away at all [Music] it sounds like it's right here guitar through that amp in this room it's a very familiar sound but I it's a very familiar sound that I've only experienced with headphones on tracking guitar and hearing the guitar through my computer in a digital and I'm going to leave all the science up to Matt who is the staff acoustical engineer at shore in Niles we measured the noise of this room and it is negative 5 dB yeah so it's hard because with any DB that you need a reference basically to calculate the DB level so the reference for zero DB is basically what they consider the threshold for human hearing which is 20 micro Pascal and this room is quieter than the threshold of human hearing so it's actually like 5 DB below like what you can even sense wow it's like the quietest thing for me being a drummer I hear mostly ringing when I come in here the size of the room really determines how low in frequency you can be anechoic to so with this size we're down to about 80 Hertz that's where we touched down to 57 layers of drywall yeah tip to tip it's sixteen point four feet and one direction fourteen feet four inches and the other and height tip to tip and around 22 by 24 as you can see we're suspended sort of halfway yeah there just looked like some torture pit yeah it looks like a mortal kombat like the floor is like this yeah I think the match that we're on with a fine mesh underneath to catch a everyone's change and there's like the exact same sound spikes from the ground beneath so let me talk a little bit about the testing so we have this rail system so we can kind of configure the room for whatever we need to test this like is our typical mic test setup so I just grabbed like an SM 81 and this is the source speaker it's a coaxial driver because you want the source to be coincident like if you had a two-way where you had a tweeter up here and a Wolford down here now you've got a different path length yeah I mean the tweeter and the Wolfer and that's gonna mess up your measurement same thing as like having reflections like basically the problem with reflections is you're getting now you have delay and path and you're getting comb filtering and stuff so so we get it set up and then we can run the test and this little turntable here will let us look at different angles or run polar responses so like all the when you look in the user guide or like our literature those frequency responses and polar responses were created in this room robots are cool I love that it just moves do you know if there's any truth to any of the stories about if you stay in here for a certain amount of time you go crazy I don't know do I seem crazy because I've spent a lot of time I left a microphone running while we were in this weird limbo environment it was so so strange and here are some of the highlights I think I thought it was my stomach [Laughter] testing testing testing yeah you're like yeah like hearing oh if you are in here for a now are you going sane clearly total rubbish but actually being here I don't think that's true still but it is far far more of a different switch I guess I'm making any sense yes maybe I am going and saying it is seriously odd to be in here with no lights on and not hear anything other than like every year you like feel your heartbeat you know a bit more yeah almost like a sizzle and I wonder if it was like something like really high-frequency hearing damage or something I heard all my stomach gurgles every single position of them inside my hepta man the first little bit was just disorienting and weird but then after like a minute or so it's like I get used to this okay so he didn't stay in long enough to be driven insane we got 10 minutes as opposed to probably hours and hours that it would take and that would just be difficult because this was a working anechoic chamber it was already lucky that Sauron and Matt gave up their time to talk us through exactly what we were experiencing why we were experiencing it and exactly what goes on in there when they are testing out microphones I know the weirdest thing we found in here was yeah a bullet casing yeah so I was like I was actually in here and I was like looking for something I dropped because obviously something it's like we put down this super fine mash because otherwise it's like lost and looking like what is this and it was like a spent 9 millimeter like a bullet casing I was like so seems weird right the only logical explanation is that we allowed the Niles Police Department to use the building for active shooter training and I think they weren't supposed to be in here but I think some cop is like Oh check it out like an echo chamber wonder what it sounds like massive thank you to Andrew Robin Jeff for accompanying me in this super weird crazy experience it was so much fun to hang out with them massive thanks to Soren and Matt for sharing their expertise and letting us in there and letting us film of course and having worked for sure in the past I know what an outstanding company they really are and there's a reason they've been around for 93 years they really really do take care with every single product and yeah I will always always love that brand and everything I use microphone wise is by sure give this video a thumbs up comment below with your favorite moments maybe ring that bell just in case you want to see any of my videos again and otherwise I will see you next week [Music] you

Channel: Mary Spender

Views: 1,857,358

Rating: 4.8554077 out of 5

Keywords: Mary Spender, Tuesday Talks, Mary Spender Music, Family Friendly, Rob Scallon, Andrew Huang, Shure Microphones, Silence, Total Silence, Anechoic, Crazy, Insane, Anechoic Chamber, Does silence make you crazy?, echo, sound, audio, reverb, sensory deprivation, acoustics, wave, decibels, fiberglass wedges, human hearing, quietest room, quietest room on earth

Id: aC-LKEpaR1s

Length: 12min 3sec (723 seconds)

Published: Tue Jun 11 2019

Reddit Comments

[u/Rogue2166]

Anechoic chambers are cool, but this one is only -5db below the human threshold. Microsoft has the quietest at over -20db below human threshold and is certified quietest by Guinness:

https://www.cnn.com/style/article/anechoic-chamber-worlds-quietest-room/index.html

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A 747 in that room would sound like a faint conversation on the outside.

[u/guyFCR]

Veritasium also made a pretty interesting video about this room. https://www.youtube.com/watch?v=mXVGIb3bzHI

[u/CatOnProzac]

Anechoic Chamber

[u/Whisper_Man]

I build these rooms! AMA

[u/[deleted]]

Wow I didn't think I'd ever see a Mary Spender video on this sub.

[u/SecretOil]

I am so confused by that display behind her; are those massive microphones or what?

[u/sedeyus]

I was thinking how they could possibly use this in A Quiet Place sequel.

[u/saltymike]

it must feel like a black hole of sound.

[u/dexcel]

Quietest place on earth, except they won’t stop talking and shut up.