The residents of the neighborhoods near Glen Drive in Sterling, Virginia — a community in Loudoun County — began noticing the noise after a large data center campus opened adjacent to their homes. It was not loud in the way a passing truck is loud. It was a continuous, high-pitched whine that persisted through the night and into the morning. As one resident described it to a journalist: “People talk about the cloud like it’s something floating in the sky, but for those of us living right next to these facilities, the cloud comes with a noise and feeling like I have allergies year-round, whenever I’m in my house.” Another resident said the noise was “almost like you have a headache all the time.”
The facility generating the noise was a Vantage Data Centers campus — one of more than 200 data centers in Loudoun County, which hosts a disproportionate share of the world’s internet infrastructure and has been called “Data Center Alley.” The noise came primarily from the facility’s on-site gas turbines and cooling equipment, which operated continuously. Loudoun County zoning enforcement received more than a dozen complaints about the facility in a single year, and officials began the slow process of revising local ordinances to address complaints that existing noise standards were not designed to capture.
This situation is not unique to Virginia. Residents near data centers in Chandler and other parts of the Phoenix metro, in parts of the Midwest, and in communities across the country have reported similar experiences. Understanding what is causing the noise, what it does to the people living with it, and what recourse is available requires working through several distinct questions.
What Produces the Noise
A data center generates noise from multiple concurrent sources, each with different acoustic characteristics.
Cooling towers and HVAC systems are typically the dominant source of operational noise. Cooling towers use large fans to move air across water, dissipating heat through evaporation. The fans run continuously at high speed and generate significant broadband noise — a combination of frequencies that produces the sustained hum or roar that neighbors closest to the facility most commonly describe. On large hyperscaler campuses or colocation facilities with dozens of cooling tower units, the aggregate noise output is substantially greater than any individual unit.
Chillers — large refrigeration units used in more controlled cooling systems — produce mechanical noise from compressors and pumps, including low-frequency components that can be particularly difficult to mitigate and that travel long distances.
Backup diesel generators are tested on a regular schedule — typically once a month, sometimes more frequently — and are activated during power outages. Generator testing produces significantly more noise than normal operations, often at levels well above any data center’s baseline operational noise. These tests typically last one to several hours and are often conducted during business hours, though the timing varies by facility and jurisdiction.
Transformer hum is a lower-amplitude but often more tonally distinct sound: an electrical hum at 60 Hz (the frequency of the U.S. electrical grid) that can be perceived as an annoying drone by neighbors within a few hundred feet. Because transformer hum is at a fixed, recognizable frequency, it is particularly difficult for the human brain to habituate to or filter.
Some newer facilities, like the Vantage campus in Sterling, generate electricity on-site using natural gas turbines rather than drawing all power from the grid. On-site turbines introduce combustion noise and exhaust in addition to mechanical vibration, and can produce noise characteristics that differ significantly from conventional cooling-only operations.
How Noise Is Measured and What Standards Apply
Noise is measured in decibels — a logarithmic scale in which an increase of 10 decibels represents a doubling of perceived loudness. There are different weighting systems for measuring decibels that correspond to how human hearing perceives different frequencies.
A-weighted decibels (dBA) are the most common measurement unit in noise ordinances. The A-weighting filter attenuates low and very high frequencies to reflect the frequencies to which human hearing is most sensitive. This makes dBA measurements appropriate for assessing most types of community noise.
C-weighted decibels (dBC) give much less attenuation to low-frequency sound. This matters for data center noise assessment because low-frequency components — the hum of chillers, the vibration of large fans, transformer noise — may be substantially underrepresented in dBA measurements but clearly audible and disturbing to neighbors. A facility that appears to comply with a local noise ordinance measured in dBA may still be generating low-frequency noise that affects the community.
Residential noise ordinances in most jurisdictions set limits in the range of 50 to 65 dBA at the property line during nighttime hours. In Loudoun County, the industrial noise limit is 55 dBA measured at residential property lines. Neighbors have reported that noise from the Vantage facility exceeded this threshold, and county officials have acknowledged that the existing measurement standard — which uses dBA and does not separately account for tonal noise — is inadequate to capture what residents are experiencing. Officials noted that the county’s zoning ordinance “currently does not measure” tonal noise of the type residents could clearly hear.
Distance attenuates noise: sound energy decreases as it spreads over a larger area with increasing distance from the source. The standard approximation is a reduction of about 6 dBA for every doubling of distance in open air. This means that noise levels at a property line 200 feet from a cooling tower will be substantially lower than at the source — but a large facility with many cooling units will have a higher aggregate output, and low-frequency noise attenuates more slowly with distance than higher-frequency noise. For neighbors within a few hundred feet of a large data center, achieving compliance with even a 65 dBA property-line standard during nighttime hours is not guaranteed.
What the Health Research Shows
The health consequences of chronic noise exposure have been studied extensively, primarily in the context of transportation noise — road traffic, aircraft, rail — but the physiological mechanisms are not specific to noise source. According to the World Health Organization’s Environmental Noise Guidelines for the European Region, the health outcomes associated with environmental noise include annoyance, cardiovascular and metabolic effects, cognitive impairment, sleep disturbance, and adverse effects on quality of life and mental health. WHO has identified noise as one of the principal environmental causes of ill health in the western European Region, second only to air pollution.
Sleep disruption is the most extensively documented pathway. Nocturnal noise fragments sleep architecture — increasing time spent in light sleep stages and reducing time in deep, restorative slow-wave sleep — even when the person does not consciously wake. Research published in Sleep Science found that nighttime noise causes measurable biological changes including stress hormone release, and that people who experience noise-disrupted sleep suffer the following day from increased reaction time, daytime sleepiness, mood changes, and decreased cognitive performance. Nocturnal noise has provoked measurable physiological reactions at levels as low as 33 dB — well below the threshold of most residential noise ordinances.
Cardiovascular effects are also documented. Chronic noise exposure is associated with elevated blood pressure, hypertension, and increased risk of cardiovascular disease through the stress response pathway: sustained low-level activation of the sympathetic nervous system raises cortisol and adrenaline levels, which over time contributes to cardiovascular damage. WHO’s review of the evidence found “stronger evidence of the cardiovascular and metabolic effects of environmental noise” in its most recent guidance compared to prior reviews, reflecting an accumulating body of research.
Low-frequency noise specifically — the type produced by large data center cooling and mechanical systems — has additional characteristics that make it particularly harmful. The human brain has difficulty habituating to low-frequency, constant-frequency sound, meaning the auditory system does not learn to ignore it the way it eventually ignores more variable or higher-frequency background noise. Documented health effects of low-frequency noise exposure include headaches, dizziness, impaired concentration, sleep disorders, stress, anxiety, and negative effects on cognitive performance. Research on children has found that chronic exposure to environmental noise is associated with cognitive impairment — specifically in higher-order cognitive functions including logical reasoning and mathematical ability — even at levels that adults might describe as merely annoying.
Data center noise is particularly problematic because it is constant. Unlike road traffic, which diminishes at night, or a quarry that operates during business hours, a data center’s cooling systems run at all hours because the servers they are cooling do not stop. The noise at 3 a.m. is indistinguishable from the noise at 3 p.m. There is no quiet time that allows the body to recover.
What Has Happened in Communities That Have Documented Problems
Loudoun County, Virginia, is the most extensively documented case. With more than 200 data centers — the highest concentration in the world — the county has generated a corresponding volume of resident complaints and media coverage. The Vantage Data Centers campus in Sterling drew sustained complaints about a continuous high-pitched whistle from nearby residents. According to Politico’s reporting, county officials confirmed they had received more than a dozen noise complaints about the facility in a single year. County Supervisor Mike Turner publicly acknowledged that the existing noise ordinance — focused on decibel levels without accounting for tonal character — was inadequate and that the county was considering revisions.
Fairfax County, also in Northern Virginia, enacted a requirement in September 2024 that new data centers be built at least 200 feet from abutting property and undergo a noise study before approval — reflecting a direct response to resident concerns about noise from existing facilities. Chandler, Arizona, adopted a zoning code amendment requiring sound studies and noise mitigation measures for new data centers, along with a communications protocol to notify residents about construction. Both responses illustrate that local regulatory frameworks can be updated when communities apply sustained pressure.
In Phoenix and surrounding Maricopa County communities, residents near data center clusters have reported similar experiences: the continuous hum of cooling systems and generator testing that disrupts sleep and discourages outdoor activity near their homes.
What Neighbors Can Do
Documentation is the essential first step. A neighbor who has concerns about data center noise should begin keeping a noise log: date, time, weather conditions, a description of the noise, and whether it is affecting sleep, conversations, or outdoor activity. This log becomes a credible factual record for regulatory complaints and public hearings.
Noise measurement apps on smartphones — such as NIOSH Sound Level Meter, Decibel X, or similar — are not substitutes for professional measurement but can provide useful general readings and timestamps. If a facility’s noise appears to approach or exceed local ordinance limits, a professional noise measurement conducted by an acoustic consultant produces results that are defensible in a regulatory or legal context. Some communities have organized to fund a shared professional measurement.
If a data center is already operating, complaints can be filed with the local zoning enforcement office. Most jurisdictions have a code enforcement division that responds to documented complaints about zoning ordinance violations, including noise violations. Filing a formal complaint creates a public record and may trigger an official noise measurement. If the facility exceeds applicable limits, enforcement mechanisms — fines, compliance orders — may be available.
If a data center is still in the approval process — pending a conditional use permit or site plan review — the noise study requirement is a critical target for community advocacy. Requesting, at a public hearing or in written comments, that the approving authority require a pre-construction noise study, operational noise limits, monitoring during operation, and generator testing schedules and restrictions, gives the community specific protections that are far more effective than generic noise ordinance enforcement after the fact. Some jurisdictions now require noise studies as a condition of conditional use permit approval; communities in jurisdictions that do not yet have this requirement can advocate for it during the specific project approval process and in any broader ordinance revision discussions.
Politico: A Data Center Opened Next Door. Then Came the High-Pitched Whine. | WHO: Environmental Noise Guidelines Development | Sleep Science: Environmental Noise and Sleep Disturbances | Gibson Dunn: State Regulatory Treatment of Data Centers | National Association of Counties: Data Centers Primer