I'm just glad they identified the source of the hum, many people are impacted for years by unexplainable sounds, and it is maddening.<p>It took me and my neighbours a month to find the source of a hum that was resonating with our windows. It was torture, with midnight walks and lurking around potential sources, mapping nearby industrial sites, and questioning our sanity, while our windows were vibrating without a stop. We were very lucky to track it down to a badly installed air conditioning vent 200 m away.<p><a href="https://en.wikipedia.org/wiki/The_Hum" rel="nofollow">https://en.wikipedia.org/wiki/The_Hum</a>
I tried making a spectrogram: <a href="https://twitter.com/nibot/status/1269347206445756416" rel="nofollow">https://twitter.com/nibot/status/1269347206445756416</a><p>I tried using baudline[1] (a 20-year-old program!) but it didn't work out-of-the-box on my current Linux installation. Instead I found something called Sonic Visualizer[2], which, while not real-time, worked out of the box. Using Pulse Audio 'pavucontrol' it was easy to configure Sonic Visualizer to use as its input the 'monitor' channel, i.e. capturing the audio while the video played on Twitter.<p>I'd love to get baudline working again since it's able to run in realtime.<p>It looks like the main tone is at 440 Hz and tones at 400 and 480 Hz come and go. Not sure what to conclude from this. :-)<p>[1]: <a href="http://www.baudline.com/" rel="nofollow">http://www.baudline.com/</a><p>[2]: <a href="https://www.sonicvisualiser.org/" rel="nofollow">https://www.sonicvisualiser.org/</a>
Apparently they knew about the hum in advance. Under CEQA they should have had to do an Environmental Impact Report and hold public hearings. Someone is bound to sue.<p><i>UPDATE: The sound is intentional. Or, at least, known about in advance.<p>According to a statement Saturday morning by Paolo Cosulich-Schwartz of the Bridge District, "The Golden Gate Bridge has started to sing. The new musical tones coming from the bridge are a known and inevitable phenomenon that stem from our wind retrofit during very high winds."
Cosulich-Schwartz adds: "As part of the design process, the District did extensive studies on the impacts of the project, including wind tunnel testing of a scale model of the Golden Gate Bridge under high winds." Those tests, seen in a video here, showed that the bridge "would begin to hum" when air passed through it more freely.</i>
This sounds so beautiful and desolate, reminding me of a combination of the first two tracks from Aphex Twin's Selected Ambient Works Vol 2, disc 2, in particular "Blue Calx" and "Parallel Stripes" starting from 40 seconds. [0]<p>Thank you for sharing.<p>[0] <a href="https://www.youtube.com/watch?v=FXBAU8HsAqk" rel="nofollow">https://www.youtube.com/watch?v=FXBAU8HsAqk</a>
This is very similar to an Aeolian Harp, also known as a wind harp.<p><a href="https://en.wikipedia.org/wiki/Aeolian_harp" rel="nofollow">https://en.wikipedia.org/wiki/Aeolian_harp</a><p><a href="https://www.youtube.com/watch?v=CtzSm76ppS4" rel="nofollow">https://www.youtube.com/watch?v=CtzSm76ppS4</a><p>They are pretty cool art installations. The Golden Gate bridge may now be the largest such installation ever built!
I was working outside yesterday afternoon and this humming was driving me insane. I thought it was some instrument at a monastery nearby.<p>I can’t believe it’s the bridge.
There should be an app for this.<p>To get direction and location, you need acoustic samples from multiple widely-spaced locations, all synchronized. Human ears are not wide enough apart to directionalize low frequencies, but with a baseline of tens or hundreds of meters from separate cell phones, it's not hard. Run a correlator, line up the samples, compute the hyperbolas of constant time offset, (like GPS and LORAN) and find the target.<p>This needs an app with timing accurate to a millisecond or so. Can you get that from cell phones? The built-in clock synchronization isn't that good. The GPS receiver has more accurate time, but you may not be able to get at that.
I hope somebody has a chance to make high-quality samples/recordings before it's fixed. I doubt we'll get the chance to hear an instrument like this again, accidental or not.
I honestly think this is awesome and beautiful, though I might feel differently if I lived nearby just because of how relentless it is.<p>I remember years ago I had the idea that if you could design construction equipment to rotate/oscillate/whatever at frequencies that were harmonic with each other, construction noise would become musical, almost like a very loud set of wind chimes.
I rode across the bridge in high winds last week and I thought that the bridge might be failing somehow - the sound was almost unbearable - I thought a serious safety issue was potentially occurring because of a structural frequency effect. I guess the good news is that there is no emergency - bad news is maybe ear plugs on bike rides on windy days.
Holy moly I can hear this from the Inner Richmond at night, WHILE IN MY BED. I thought my tinnitus was doing something new, but it's the freaking bridge!
this is fascinating! i wonder how long it will take them to do something about it? seeing the video, i almost wish they'd keep it, but i don't live nearby, so...<p>i found a couple more video examples of accidental acoustic wind effects in architecture -- but it looks like these aren't as ever-present and loud as the Golden Gate Bridge is right now.<p>Beetham Tower - Manchester, UK: <a href="https://www.youtube.com/watch?v=Y8-MrU6lpwg" rel="nofollow">https://www.youtube.com/watch?v=Y8-MrU6lpwg</a><p>Freedom Tower - NYC, USA: <a href="https://www.youtube.com/watch?time_continue=25&v=nkjA3BvvOuw" rel="nofollow">https://www.youtube.com/watch?time_continue=25&v=nkjA3BvvOuw</a><p>in the Beetham Tower case, apparently the architect <i>lives in the tower's penthouse</i>. i bet they're frustrated that none of the fixes have completely remedied the problem.<p>links from: <a href="https://gizmodo.com/when-buildings-howl-a-primer-on-architecture-that-whis-1475982071" rel="nofollow">https://gizmodo.com/when-buildings-howl-a-primer-on-architec...</a>
Maybe they should find a way to generate electricity from the bridge, it sees plenty of wind practically every single day for the same reason the SF bay is great for sailing.<p><a href="https://patents.google.com/patent/US9444372B2/en" rel="nofollow">https://patents.google.com/patent/US9444372B2/en</a><p><a href="https://en.wikipedia.org/wiki/Vortex_Bladeless" rel="nofollow">https://en.wikipedia.org/wiki/Vortex_Bladeless</a>
Lisbon also has a bridge that you can hear from miles away: one lane in each direction has a surface made of metal grating which makes a loud hum when cars drive over it.<p>People who live nearby don't notice it (strange looks if you point it out) but I think it's sad that it's impossible to escape the constant noise in certain places.
They finally found a way to reduce the cost of real estate in SFO! Seriously, you have to wonder how someone can actually think this is OK when it can be heard from far away at all times and people crossing it are reporting it to be unbearably loud.<p>My prediction is this will be added to the long history of engineering disasters. It's OK, this is how we learn.<p>Here's another video I found:<p><a href="https://www.youtube.com/watch?v=sa2j9b8486I" rel="nofollow">https://www.youtube.com/watch?v=sa2j9b8486I</a>
I’m curious if there can be an impact on the wildlife out here. Animals don’t understand what the noise is, so can it disorient them in some way that could have a harmful effect?
Another 'cool' mega-instrument is the Earth Harp. Instead of transverse waves (plucking) the strings, you use compression waves (pushing) in the strings to make the vibrations. Due to some physics here, you then need a very large resonator to hear the sounds. Essentially the Earth itself. Here's a good video from the Burn at an Earth Harp performance: <a href="https://www.youtube.com/watch?v=c66w_pPnO-s" rel="nofollow">https://www.youtube.com/watch?v=c66w_pPnO-s</a>
Worse mistakes have been made<p><a href="https://en.m.wikipedia.org/wiki/Tacoma_Narrows_Bridge_(1940)" rel="nofollow">https://en.m.wikipedia.org/wiki/Tacoma_Narrows_Bridge_(1940)</a><p>Pretty sure every bridge engineer knows that one. Amusing that the lesson didn't generalize.
There is this building that has a similar kind of noise: <a href="https://en.m.wikipedia.org/wiki/Beetham_Tower,_Manchester" rel="nofollow">https://en.m.wikipedia.org/wiki/Beetham_Tower,_Manchester</a>
The second law of thermodynamics says that the energy of reducing the wind's speed has to go somewhere. It's either going to push the bridge around, make noise by generating vibration, generate electricity as in a wind turbine, or some combination of the three.
Does anyone know if they are planning on removing the slats? Maybe if they randomly changed the spacing of the slats if it would alleviate the problem ?
I like how this article and lots of people's tweets mention '2020.' As if 2021 is going to be any better and things won't just remain permanently horrible! Have a nice day!
The expressway I-5 bridge in Seattle is notoriously loud and can be heard for miles around. Interestingly, the sound from the busy topmost lane doesn't seem to make it to the ground. You can verify this during the brief pause when the express lane changes directions. I believe the traffic noise from the express-lane is reflecting off the underside of the upper lane. Seems like a diffusing layer on the underside of the upper lane would reduce the sound getting to the city below.
Reminds me of Google’s old Crittenden Lane buildings. The buildings have exterior metal vertical slats over windows for shade control. They sing when it’s windy.
I'm glad the tones produced are a whole step apart instead of a half step or something smaller. I wonder if they took that into account in the design; it always drives me nuts when two neighboring beeping electric turn-styles beep in just slightly different tones.
We just live with a very loud sound at our house. Run water for any reason. When you stop, some 0-15 seconds later an enormous sound reverberates thru the house. Plumber says its 'water pipes growing or shrinking, rubbing against the straps'. But it goes on for 10-30 seconds. No water pipe in the world moves that long/that much?
According to following, engineers knew this sound would happen during high winds from the west.<p><a href="https://www.theguardian.com/us-news/2020/jun/06/golden-gate-bridge-san-francisco-sings" rel="nofollow">https://www.theguardian.com/us-news/2020/jun/06/golden-gate-...</a>
I wonder if they will now need to install thousands of rubber vibration dampeners wedged between the slats.. like large versions of tennis racket string dampeners.. if that is possible to do without catching too much of the wind trying to pass through. Maybe only on every other slat, or every three slats, could reduce the noise at least somewhat.<p>So then someone would need to custom manufacturer all of those pieces of rubber and then they would all need to be jammed in there. But then the weather would probably degrade then over time.<p>I just wonder how many millions are going to be spent on mitigating this.
I don't live in SF but have visited a few times. I would be incredibly angry if someone arbitrarily decided to add a whole bunch of noise into my environment for no good reason. However "interesting" the noise may be to some people, having to deal with it in my daily life would be awful! I cannot comprehend how a person or group could be allowed do something like that.
This sounds exactly like the audio synthesis I did for a recent generative sound app. I didn't know too much so a very high q band pass filter over brown noise did the trick. Do that over several voices (not necessarily harmonic) and you get something similar. Check it out: <a href="https://apps.apple.com/us/app/night-shapes/id1490540845" rel="nofollow">https://apps.apple.com/us/app/night-shapes/id1490540845</a>
Check out The Singing Ringing Tree art exhibit:<p><a href="https://youtu.be/4B0hGyKV9qs?t=12" rel="nofollow">https://youtu.be/4B0hGyKV9qs?t=12</a>
I'd assume that the engineers would have performed some form of stress tests for these installations that were actually meant to afford wind resistance and that the noise should have been noticed. Does anyone know how these conditions are tested in a simulated large structural engineering lab?
Here’s a BBC doc on the “Bristol hum” <a href="https://youtu.be/QpeKot2X_O8" rel="nofollow">https://youtu.be/QpeKot2X_O8</a><p>Makes me almost happy for my hearing loss from attending a Jack White concert in a tiny bar where he maxed out the sound system. Although that’s probably worse off.
Apparently you can hear it from pretty far away and not just as you go over the bridge: <a href="https://twitter.com/Shirin_Jnk/status/1269143410268467200" rel="nofollow">https://twitter.com/Shirin_Jnk/status/1269143410268467200</a>
I wonder what the space is in between the slats, or more precisely, the period. Working out what pitch this is, and a bit of $v=f\lambda$ might tell us which way the wind is blowing.
It sounds like a WW-II air-raid siren.<p><a href="https://www.youtube.com/watch?v=WgaCNEQzL1Q" rel="nofollow">https://www.youtube.com/watch?v=WgaCNEQzL1Q</a>
I should probably know this, but mechanical design packages include thermal modeling and fluid dynamics modeling. How about modeling for resonating in wind?
My bet: depression rate is going to increase around the bridge where the sound can be heard.<p>I wonder if you can hear it from top of Mount Tamalpais?
Given it makes sound, it vibrates at high frequency. I've troubles understanding why a vibrating bridge is "better for structural integrity". I remember some of these in the past which broke<p>Bridge engineer cares to enlighten me/us?
This reminds me... On the off chance someone reads this and happens to have a copy:<p>I once ripped this mix from, I think it was di.fm or soma.fm, called 'Quiet ambient preceding magnetic storm', but the only hdd it was on broke.