Скачать или смотреть Noise comparisons: Neighborhoods with and without data centers

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:
Braxton Boren, Assistant Professor of Audio Technology at American University
The Centers for Disease Control
Adobe Audition Analysis "Spectral Frequency Display"

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.