What’s all the data center noise about?

PRINCE WILLIAM COUNTY, Va. — It's often said that good fences make good neighbors, but neighbors in the Great Oak Subdivision say, they’re not good enough to quiet the noise next door.

“We're about 700 feet from the data center right here,” said Dale Brown, Great Oak homeowner’s association president from alongside a neighbor’s yard. “It's just really, really loud.”

Along with an audible hum, the Amazon Web Services Data Center in Manassas and others nearby have also been generating rumbles of complaints from the nearby community.

“These data centers are loud, noisy beasts and they are being built too close to residential areas,” said Roger Yackel, who’s been active in the community’s pushback on data centers that they say are being approved without consideration of the nearby homes and schools. “That's not something that we should have to live with.”

John Lyver, a retired NASA analyst, has taken to tracking the noise from the data centers in his neighborhoods.

“I’m finding that the noise is far worse than anybody ever figured it was going to be,” he said.

Before tech came to his doorstep, Brown worked in tech, where he says he worked on building data centers.

“It does not have to be that noisy,” said Brown.

THE QUESTION:

What is it about that hum that makes it so tough for some neighbors to tune out, and can living with continuous hum really be harmful?

THE SOURCES:

THE ANSWER:

We can’t assert that Northern Virginia Data Centers emit noise that’s harmful to humans in general—but we can Verify: the type of constant, low-frequency sounds resonating from the buildings can be harder to silence, be more annoying, and even pose health risks.

WHAT WE FOUND:

We measured the volume and analyzed the frequency of the noise from the sidewalk right outside the Amazon Web Services Data Center in Manassas, from the yard where we chatted with Dale Brown, and the nearby Oak Valley subdivision, close to a proposed data site.

Outside the data center was louder, but the frequency analysis found very similar wavelengths from the Great Oak neighborhood. There was no measurable hum from Oak Valley.

“There's not a ton of research on data center noise,” said Braxton Boren, assistant professor of audio technology at American University. He did take a look at some existing research and measurements of a data center in Texas, and found similar conclusions to our measurements in Prince William County: low, consistent hums.

“Low frequencies have very, very long wavelengths, so they're not able to be absorbed by air molecules,” he explained. “You could build a wall, and those wavelengths would by a process called diffraction, they would sort of bend and go right over it. You can't even block them in the normal way that you would with a lot of other sounds.” 

The data center noise can be so low, it’s just barely within the range of frequencies to which our ears are most sensitive and Boren said we can still be effective by those and even lower noises.

That’s because even when we stop noticing it, our brains still register the sound, which can have an impact.

"My auditory system is picking up on a lot of things behind the scenes all the time. Because if anything is sneaking up behind me, the auditory system is the thing that needs to let to let me know about that because my eyes aren't going to tell me that," Boren explained. "So there can be things in our context which we're not consciously aware of, it's not sort of at the forefront of our attention, but the auditory system is gauging those things and it will probably let us know about it."

The CDC warns a noise not loud enough to cause hearing damage can still cause stress, anxiety, and even heart disease when continuously exposed to it.

“We have some semblance of a feeling that something's not quite right with us,” said Boren. “These feelings of low frequency hums are often indicative of that.”

Lyver says that’s something he and his neighbors notice.

“Our brains never get a chance to rest, never get a chance to get away from it,” he said.

Another reason why some neighbors feel they can’t silence the noise around data centers could be because this whole topic is the center of town talk. One element of audio annoyance--a real scientific concept—is the belief a sound doesn’t belong in someone’s environment.

“It's perceived as symbolic of other things like an intruder to the neighborhood,” said Boren.

That means the sound can feel more stressful than others that might even be more noticeable—like the punctuating noise from the nearby airport and passing planes overhead.

“They're transient, and the airport was here before Great Oak,” said Brown. “This”—gesturing toward the data center—“came after Great Oak.”

Neighbors are also concerned about the additional data centers in the works nearby--which they worry will only serve to amplify the noise.

"From here, all of their noises add together," said Lyver. "The other example that I use is a motorcycle. A Harley-Davidson is loud. I can put up with it. You put three or four them together, okay, it's louder. I can put up with it. But you have Rolling Thunder? You're breaking windows."

But in Prince William County, we also heard something we didn’t expect.

“I am not against data centers,” insists Yackel. “I am against building noisy data centers next to residential community.”

“I firmly believe that we need data centers,” said Brown. “For me, it's a matter of how it's built and what investment is made in making it to be quiet, as opposed to allowing it to be a quick [return on investment] and building it cheaply and noisily.”

Because even though these folks worry they can’t live with them--you could say they can’t live without them, either.

“The neighborhood needs Amazon,” said Lyver—as an Amazon delivery truck passed behind him, dropping a package at a neighbor’s door. “I firmly believe that we need data centers, but I don't want to hear them.”

While they're not the only operator of data centers in Northern Virginia, we did reach out to Amazon to find out what they're doing about these complaints. They sent VERIFY the following statement:

“We design and engineer our data centers to minimize the impact on our neighbors and the environment. Although we meet all of the relevant sound and environmental standards for our facilities in Virginia, in a very small number of isolated instances we have received feedback from neighbors about some unwanted sounds in their community. As soon as we were made aware of this, we engaged directly with residents to conduct detailed sound evaluations to understand the issues they are experiencing, immediately installed sound shrouds to lower sound levels, and are now reengineering and installing new equipment to continue to eliminate unwanted sounds.”

Community members also tell us they are so concerned about future developments and the issues that might come with those data centers; Amazon says they believe their changes will help inform best practices for any new data centers built by AWS or other developers.